Home

Lake Shore Model 455 DSP Gaussmeter Manual

1. Use the A or WV key to select from Off or On Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display Operation 4 21 Lake Shore Model 455 Gaussmeter User s Manual 4 11 RELAYS The Model 455 has two mechanical relays designated Relay 1 and Relay 2 The relays are most commonly associated with the high and low alarms but they can also be controlled manually and used for other purposes Both relays default to their normal state when instrument power is turned off The relays have two modes of operation Manual The relay is turned off normal or on active manually from the front panel or over computer interface Alarm The relay is configured to follow the operation of the alarms The user can tie the action of the relay to the high alarm low alarm or both alarms The relay is activated any time the associated alarm is active To begin the relay setup process press the Relay key The following relay setup screen appears as a prompt for relay selection Use the A or V key to select Relay 1 or Relay 2 Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display The next relay setup screen appears as a prompt for operating mode Use the A or V key to select the relay mode for manual operation Of
2. 2 3 x2 x 12 in Bore 19 mm diameter x 279 mm deep 0 75 x 11 in See Figure 7 18 MAN 455 Model 455 Gaussmeter User s Manual RM 1 2 Half Rack Mounting Kit for One 1 2 Rack Gaussmeter Half length mounting panel and mounting g ears to attach one Model 455 to a 483 mm 19 inch rack mount space See Figure 3 7 Dual Mounting Shelf for Two 1 2 Rack Gaussmeters Mounting panel and mounting ears to attach RM two Model 455 DSP Gaussmeters to a 483 mm 19 inch rack mount space See Figure 3 8 Accessory included with a new Model 455 Probes and Accessories 7 1 Lake Shore Model 455 Gaussmeter User s Manual 7 3 LAKE SHORE STANDARD PROBES There are several types of Lake Shore Model 455 probes available Axial Gamma Tangential and Transverse generally named for the Hall sensor orientation Because the Model 455 covers such a wide magnetic field range 0 01 mG to 350 kG three probe ranges are available High Stability HST High Sensitivity HSE and Ultra High Sensitivity UHS Please consult the factory for availability of probe types not detailed in this section 7 3 1 Hall Probe Selection Criteria Proper selection of a Hall probe is probably the most difficult and important decision to make after choosing the Model 455 Utilizing the wrong probe may lead to less than optimal accuracy or even worse costly damage Probe Application Field measurement application is the controlling factor
3. cccesceceeceeceeeeeeeaeeeeeeeseneeeseaeeesaeeeeaeeseeneess 4 17 Peak Operation Relative ccccccccceeesceceeeeeceeeeeeeaeeeeaeeseeeeeceaeeeeaaesseeeeseeeeeseaeeesaeeeeeeeneeeess 4 18 Peak Operation Analog Output 1 and 3 4 18 TEMPERATURE MEAGUDREMENT 4 19 Re EE 4 19 ELE Kee ee be beten Meo 4 22 ANALOG OUTPUT TE 4 23 Analog Output 3 Mode Setting ccccceeeeeeceeeeeeeaeeeeeeeceeeeeceaeeesaaeseeeeeseaeeesaeeseaeseeeeesaas 4 23 Analog O tp t 3 Polarity EE 4 25 Analog Output 3 Volt mt 4 25 LOCKING THEsKEY RE 4 26 DEFAULT PARAMETER VALUES ed eege eebe tinea ahi ei ania ed 4 27 Table of Contents Lake Shore Model 455 Gaussmeter User s Manual TABLE OF CONTENTS Continued Chapter Section Title Page 5 ADVANCED OPERATION isnc cits cccccetecscccitenccctinsscee tdectecctaveccectissccceunsentechdveccccdavectechussdccctaeentece 5 1 5 0 EISE TTT 5 1 5 1 PROBE MANAGEMENT riran reerd i Ara aay eN Ua Aa KRAE Seed ege Eed Dees 5 1 5 1 1 Clear Probe Zero Calibration ccccccecsscccceesneceeecneeeeeceaeeeeecaaeeeeecaaeeeesceaeeseesaeesessneeseneaas 5 1 5 1 2 Probe Serial N rgb t Ge tege cates Add EE NAAR ct Jabedvaa ocestsbadusachad caveit ah satelvad asta 5 1 5 1 3 Field and Temperature Compensation cccccceeeeeeeeeeeeeeeceeeeeeaeeeeaaeseeeeeeeeeeeaeeteeeseneeeed 5 1 5 1 4 Extension Cable aeaa araa AA aiea Eaa Eaa Eeti ia a aAA AAT AAE a TaBe RAEE a 5 2 5 2 HALG GENERATOR narena a ae ai a R E 5
4. 1 Magnitude check 2 Algebraic check lt low value gt Sets the value the source is checked against to activate the low alarm 350 kG lt high value gt Sets the value the source is checked against to activate high alarm 350 kG lt out in gt Specifies the alarm to trigger on value outside or inside of setpoints 1 Outside 2 Inside Examples ALARM 1 1 100 300 1 term Turns alarm checking on Activates alarm if the absolute value of the field is over 300 Gauss or if the absolute value of the field is below 100 Gauss ALARM 1 2 100 300 2 term Turns alarm checking on Activates alarm if the value of the field is between 100 Gauss and 300 Gauss ALARM Alarm Parameter Query Input ALARM term Returned lt off on gt lt mode gt lt low value gt lt high value gt lt out in gt term Format n n tnnn nnnE nn t nnn nnnE nn n Refer to command for description ALARMST Alarm Status Query Input ALARMST term Returned lt state gt term Format n lt state gt 0 Off 1 On ANALOG Analog Output 3 Parameter Command Input ANALOG lt mode gt lt polarity gt lt low value gt lt high value gt lt manual value gt lt voltage limit gt term Format n n tnnn nnnE nn tnnn nnnE nn tnnn nnnEtnn on lt mode gt Specifies data the analog out 3 monitors 0 off 1 default 2 user defined 3 manual lt polarity gt Specifies analog output polarity 1 unipolar 2 bipolar lt low value gt If lt mo
5. 4 1 TURNING POWER ON Verify that the AC line voltage indicator in the fuse drawer window shows the appropriate AC line voltage before turning the instrument on The instrument may be damaged if it is turned on with the wrong voltage selected Instructions for checking line voltage selection are given in Section 3 3 1 Attach the power cord and turn on the instrument as described in Section 3 3 4 When the Model 455 is turned on the display reads Lake Shore for a few seconds and the alarm beeper sounds briefly to indicate the instrument is initializing Most instrument setup parameter values are retained when power is off with only a few exceptions When the instrument is powered on for the first time parameter values are set to their defaults listed in Table 4 1 When initialization is complete field readings will appear on the display Messages will appear in the reading locations on the display if the instrument has not been properly configured Refer to Section 8 6 for a list of error messages The Model 455 should be allowed to warm up for a minimum of 30 minutes to achieve rated accuracy LakeShore 455 DSP Gaussmeter Relative Alarm Remote e d d DC RMS Analog Zero Max Local Output Display Autorange Probe Escape Hold Peak Pe PS Pi Sei Pe E W 9 Select Interface Alarm Relay Units Range Probe Enter Relative Reset E Wi 9 9 Wi m y 455_Front_3 bmp Figure 4 1 Model 455 Front Panel Opera
6. Lake Shore Model 455 Gaussmeter User s Manual 1 3 SAFETY SUMMARY Observe these general safety precautions during all phases of instrument operation service and repair Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended instrument use Lake Shore Cryotronics Inc assumes no liability for Customer failure to comply with these requirements The Model 455 protects the operator and surrounding area from electric shock or burn mechanical hazards excessive temperature and spread of fire from the instrument Environmental conditions outside of the conditions below may pose a hazard to the operator and surrounding area e Indoor use e Altitude to 2000 meters e Temperature for safe operation 5 C to 40 C e Maximum relative humidity 80 for temperature up to 31 C decreasing linearly to 50 at 40 C e Power supply voltage fluctuations not to exceed 10 of the nominal voltage e Overvoltage category II e Pollution degree 2 Ground the Instrument To minimize shock hazard the instrument is equipped with a 3 conductor AC power cable Plug the power cable into an approved three contact electrical outlet or use a three contact adapter with the grounding wire green firmly connected to an electrical ground safety ground at the power outlet The power jack and mating plug of the power cable meet Underwriters Laboratories UL and
7. The letters DTE near the interface connector stand for Data Terminal Equipment and indicate the pin connection of the directional pins such as transmit data TD and receive data RD Equipment with Data Communications Equipment DCE wiring can be connected to the instrument with a straight through cable As an example Pin 3 of the DTE connector holds the transmit line and Pin 3 of the DCE connector holds the receive line so the functions complement It is likely both pieces of equipment are wired in the DTE configuration In this case Pin 3 on one DTE connector used for transmit must be wired to Pin 2 on the other used for receive Cables that swap the complementing lines are called null modem cables and must be used between two DTE wired devices Null modem adapters are also available for use with straight through cables Section 8 11 1 illustrates suggested cables that can be used between the instrument and common computers The instrument uses drivers to generate the transmission voltage levels required by the RS 232C standard These voltages are considered safe under normal operating conditions because of their relatively low voltage and current limits The drivers are designed to work with cables up to 50 feet in length Remote Operation 6 17 Lake Shore Model 455 Gaussmeter User s Manual 6 2 3 Hardware Support The Model 455 interface hardware supports the following features Asynchronous timing is used for the individual bit d
8. 6 0 3 4 20 15 1 5 10 0 4 5 0 0 Error Deviation from perpendicular a Effect of angular variations on percentage of reading error where percent error 1 cos a 100 Figure 3 5 Effect Of Angle On Measurements 3 6 Installation Lake Shore Model 455 Gaussmeter User s Manual 3 6 AUXILIARY I O CONNECTION The Auxiliary connector is a 25 pin D sub plug This provides access to the analog outputs and relays The pins are defined in the following table Auxiliary_lO bmp Figure 3 6 Auxiliary UO Connector Pin Description Pin Description 1 Analog Out 1 14 Ground 2 Analog Out 2 15 Ground 3 Analog Out 3 16 Ground 4 No Connection 17 No Connection 5 Internal Use Only 18 No Connection 6 Internal Use Only 19 No Connection 7 No Connection 20 No Connection 8 Relay 1 NO 21 No Connection 9 Relay 1 COM 22 No Connection 10 Relay 1 NC 23 No Connection 11 Relay 2 NO 24 No Connection 12 Relay 2 COM 25 No Connection 13 Relay 2 NC Analog Output 1 The first voltage output gives access to amplified voltage signal directly from the probe This voltage is corrected for the nominal sensitivity of the probe and provides the widest bandwidth of the three voltage outputs In wideband AC mode its signal can be viewed on an oscilloscope to observe the shape of AC fields In peak mode the output can be used to view pulse shape or other character
9. 6 3 1 Interface Commands Alphabetical Listing CLS Clear Interface Command Input CLS term Remarks Clears the bits in the Standard Event Status Register and Operation Event Register and terminates all pending operations Clears the interface but not the instrument The related instrument command is RST ESE Standard Event Status Enable Register Command Input ESE lt bit weighting gt term Format nnn Remarks The Standard Event Status Enable Register determines which bits in the Standard Event Status Register will set the summary bit in the Status Byte This command programs the enable register using a decimal value which corresponds to the binary weighted sum of all bits in the register Refer to Section 6 1 4 2 1 ESE Standard Event Status Enable Register Query Input ESE term Returned lt bit weighting gt term Format nnn Refer to command for description ESR Standard Event Status Register Query Input ESR term Returned lt bit weighting gt Format nnn Remarks Bits in this register correspond to various system events and latch when the event occurs When an event bit is set subsequent events corresponding to that bit are ignored Set bits remain latched until the register is reset by this query or a CLS command Refer to Section 6 1 4 2 1 IDN Identification Query Input IDN term Returned lt manufacturer gt lt model gt lt serial gt lt date gt term Format aaaa aaaaaaaa aaaaaaa
10. B l i Cable Length 6 6 feet f 0 125 0 020 T 0 36 0 030 dia 2 5 This table is for L 3 inches and S 0 375 inch Temperature Coefficient Corrected Operating Contain Model Act St Freq i nee W T A Se w des Type Accuracy Temp maximum Temperature Area Material Range of Reading Range Zero Calibration Sensor HMFT DC to 0 20 to 30 kG spe Ge 3E03 VR A 436 p gos 0 040 20 kHz 0 25 30 35 kG E E HMFT max max i we DC to 0 10 to 30KG err ome 3E03 VF PPOX exible 800 Hz 0 15 30 35 kG o cto W 75 C Key No HMFT 2903 VH d Tubin nue Ke 9 DC tO uer 40 50 to 35 kG 0 09G C 0 015 C 2903 VJ o 085 E 0 065 E 20 kHz 0 005 ee approx DC to st 4 0 25 to 35 KG 0 13G C 0 005 C 800 Hz This table is for L 15 0 5 inches and S 0 75 inch HMET Flexible DC to uer 22 20 to 30 kG AFIS VR e 0 040 Tubing 20 kHz 0 25 30 35 MEI go 0 09G C 0 015 C 0 150 0 C to ge dia amp Epoxy op ep HMFT S i DC to 0 10 to 30 kG approx Fiber HST 4 o E ope 4F15 VF glass 800 Hz ase 0 15 30 35 kG Sean e One probe is included with the purchase of the Model 455 Model numbers shown in bold are the probes available to chose from Flexible_Transverse bmp Figure 7 7 Definition of Lake Shore Flexible Transverse Probes FLEXIBLE AXIAL PROBE edel SSES L ae A E Lies K nu KR Cable Length 6 6 feet 0 26 0 0230
11. Slide the top panel back and remove it from the unit INSTALLATION Slide the top panel forward in the track provided on each side of the unit Carefully replace the back bezel by sliding it straight into the unit Use 5 64 hex key to install 4 screws attaching top panel to unit Use 5 64 hex key to tighten 2 screws attaching rear bottom panel to unit If required reattach 19 inch rack mounting brackets OY OR E tS Connect power cord to rear of unit and set power switch to On I 8 9 FIRMWARE REPLACEMENT There is one integrated circuit IC that may potentially require replacement See Figure 8 3 for the IC location e Main Firmware Erasable Programmable Read Only Memory EPROM U16 Contains the user interface software Has a sticker on top labeled M455MF HEX and a date Use the following procedure to replace this IC 1 Follow the top of enclosure REMOVAL procedure in Section 8 8 2 Locate the IC on the main circuit board See Figure 8 3 Note orientation of existing IC Service 8 5 mf ee maea 2 U52 LS Ka Ra C87 CRIO ef Ca Di w f ees Ea ez bd mim g P eapa Lake Shore Model 455 Gaussmeter User s Manual 5065 BI DS Ze ES BS RAS ew Sa Bez LS e R26 E Oz Dees SR E AH g P7 Gay ca R45 CS puzza eno ei H g R EN u7 EN Us D a E oO R12 s u us 2 o g Ez Figure
12. The Service Request Enable Register is programmed by the user and determines which summary bits of the Status Byte may set bit 6 RQS MSS to generate a Service Request Enable bits are logically ANDed with the corresponding summary bits see Figure 6 4 Whenever a summary bit is set by an event register and its corresponding enable bit is set by the user bit 6 will set to generate a service request The Service Request Enable command SRE programs the Service Request Enable Register and the query command SRE reads it Reading the Service Request Enable Register will not clear it The register may be cleared by the user by sending SRE 0 From Operation Event Register From Standard Event Status Register From Output Buffer z ll RER 128 64 32 16 8 4 2 1 Decimal Not Not Not Not Status Byte Register STB RQS Generate service request SRQ Reset by serial poll Service Request Enable Register SRE SRE z 6 5 4 3 21 11 0 s8 128 64 32 16 8 4 2 14 Decimal Not Not Not Not By aie Used Used Used Used E Name Figure_6 4 bmp Figure 6 4 Status Byte Register and Service Request Enable Register 6 1 4 3 3 Using Service Request SRQ and Serial Poll When a Status Byte summary bit or MAV bit is enabled by the Service Request Enable Register and goes from 0 to 1 bit 6 RQS MSS of the status byte will be set This will send a service request SRQ interrupt m
13. The following alarm setup screen appears as a prompt for using the alarm in magnitude or algebraic mode Use the A or V key to select from Magnitude or Algebraic Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display When the alarm feature is used to detect an error condition an active alarm state is expected when the field reading is higher than the high alarm setpoint or below the low alarm setpoint This operation is achieved by setting the inside outside parameter to outside It is called outside because the alarm is active when the reading is outside the range of the two setpoints During magnet testing or sorting it is often desirable to have the alarm active when the field reading is inside or between the two setpoints This operation is achieved by setting the inside outside parameter to inside To configure the Alarm inside outside setting continue from the magnitude algebraic mode screen or press and hold Alarm and then press Enter until the following screen appears as a prompt for selecting the inside outside setting Use the A or V key to select from Inside or Outside Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display The following images demonstrate different combinations of Inside Outside with Magnitude
14. lt negative peak gt lt positive peak gt term Format nnn nnnE nn nnn nnnE nn Remarks Returns the negative and positive peak readings 6 34 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual RDGREL Relative Reading Query Input RDGREL term Returned lt relative reading gt term Format nnn nnnE nn Remarks Returns the relative field reading RDGTEMP Probe Temperature Reading Query Input RDGTEMP term Returned lt temperature gt term Format nnn nnnE nn Remarks Returns the probe temperature reading in a format based on the present temperature units REL Relative Mode Command Input REL lt off on gt lt setpoint source gt term Format n n lt off on gt Specifies Relative mode off or on 0 off 1 on lt setpoint source gt Specifies source of relative setpoint 1 User defined 2 Present Field Example REL 1 1 term Relative mode turned on configured to use the User defined setpoint Refer to RELSP command REL Relative Mode Query Input REL term Returned lt off on gt lt setpoint source gt term Format n n Refer to command for description RELAY Relay Parameter Command Input RELAY lt relay number gt lt mode gt lt alarm type gt term Format n n n lt relay number gt Specifies which relay to configure 1 Relay 1 2 Relay 2 lt mode gt Specifies relay mode 0 Off 1 On 2 Alarms lt alarm type gt Specifies the alarm type that activates the re
15. 0 01 26 Connect the 300 mQ resistor across the Gaussmeter input of the Model 455 using a proper 4 lead connection 27 Configure the Model 455 for 100 mA excitation current HALLCS 1 28 Read the resistor using the Model 455 RDGOHM Store as EXPECTEDRESISTANCE 29 Configure the Model 455 range to the 350 mQ range RANGE 4 30 Read the resistor using the Model 455 RDGOHM Store as ACTUALRESISTANCE 31 Calculate the Gain Calibration Factor GCF EXPECTEDRESISTANCE ACTUALRESISTANCE Test this factor to be 1 0 42 32 Send the Gain Calibration Factor GCF to the Model 455 CALG 1 4 lt GCF gt 33 Read the resistor using the Model 455 RDGOHM Verify the reading to be EXPECTEDRESISTANCE 0 01 34 Repeat steps 26 thru 33 for the 35 mQ and 3 5 mQ ranges range 3 and 2 using the 30 mQ and 4 3 mQ resistors respectively 35 Send the Gain Calibration Factor GCF calculated for range 2 to range 1 The hardware gains for those two ranges are equivalent 36 Send the CALSAVE command to save the calibration constants into non volatile memory 8 11 2 2 Gaussmeter Calibration 10 mA Excitation Ranges This section describes the method of calibrating the 10 mA current source that may be used for future Hall sensors The five ranges of the Model 455 will need to be calibrated for each current setting The highest range is for each current is calibrated using a 33 2 Q resistor that is measured using the 3458 in a four lead resis
16. 3 Remove instrument power cord 4 5 100 120V 0 5A 5x20mmT 220 240V 0 25A 5x20 mm T 6 Re assemble line input assembly in reverse order 7 Verify voltage indicator in the line input assembly window 8 Connect instrument power cord 9 Turn power switch On I 8 6 ERROR MESSAGES The following messages appear on the instrument display when it identifies a problem during operation The messages are divided into three groups Instrument hardware messages are related to the instruments internal circuits or non volatile memory If one of these messages persists after power is cycled the instrument requires repair or recalibration Measurement messages are most often associated with over field conditions caused by an improperly selected field range or excessive noise on the measurement leads or a missing or illegal probe If these messages persist after proper configuration the instrument may require repair Illegal operation messages remind the operator when a feature is locked out or the instrument is not configured to support a feature Instrument Hardware Defective RAM Internal RAM is defective and must be replaced 3 EEPROM contents are corrupt and parameter values will be reset to default Eye BETBOM Reoccurrence may indicate defective EEPROM Calibration may be affected Input Not Responding Internal processor communication has failed Invalid Calibration Instrument has not been calibrated or calibration memory has
17. Model 455 DE 9P Standard Null Modem Cable DE 9S to DE 9S PC DE 9P 5 GND lt H _ 5 GND 2 RD in Ore A TD out 3 TD out TD RD in 4 DTR out gt 6 DSR in 6 DSR in DO r _ sOWdAL DTR oun 1 NC TAIT RIS tt 7 DTR tied to 4 8 CTS in 8 NC ae 1 DCD in Model 455 to PC Serial Interface PC with DB 25P Model 455 DE 9P Standard Null Modem Cable DE 9S to DB 25S PC DB 25P 5 GND lt _ _ gt _ 7 GND 2 RD in 1 TD Out 3 TD out a WUUW S R TF 3 RY in 1 NC AS 4 RTS out 7 DTR tied to 4 gt 5_CTS in 8 NC E e 8 DCD in 6 DSR in ennn eee oe 20 DTR out 4 DTR out ng 6 DSR in Model 455 to PC Interface using Null Modem Adapter Model 455 DE 9P Null Modem Adapter PC DE 9P 5 GND PV gt 5 GND 2 RD in TTT TT TT sss 3 TD out 3 TD out TT G_ lt iI_iW NGNGST LT BD RY in 1 NC TTT 4 BER Cont 6 DSR in RS 1 DCD in 4 DTR out 6 DSR in 7 DTR tiedto4 C 8 CTS in 8 NC a H RTS Cont 9 NC er H NC NOTE Same as null modem cable design except PC CTS is provided from the Model 455 on DTR Service 8 9 8 10 2 IEEE 488 INTERFACE Connector Lake Shore Model 455 Gaussmeter User s Manual Connect to the IEEE 488 Interface connector on the Model 455 rear with cables specified in the IEEE 488 1978 standard document The cable has 24 conductors wit
18. RMS Wide Band AC Block Diagram OR 455_Block_4 bmp 2 1 7 Peak Measurement The Model 455 is capable of measuring the peak amplitudes of signals either peak pulses or periodic pulses In peak mode the instrument uses a 100 mA DC excitation current The voltage that is generated by the Hall device is read by the A D at 40 kHz Output 2 Peak E Periodic d The readings are then passed through a peak detector that will capture and hold a maximum peak pulse value or calculate the value of periodic peaks Refer to Section 4 8 2 for information on how to setup the peak mode Analog Output can be used to output a real time representation of the field being measured Analog Output 2 can also be used to output a digitally derived representation of periodic fields being measured for signals up to 10 kHz Measured fields up to 20 kHz may be represented with the addition of external filters to the analog output Analog Output 2 should not be used in pulse mode since it is not fast enough to accurately re create quick pulses Pulse 455_Block_5 bmp Figure 2 5 Peak Measurement Block Diagram Background 2 3 Lake Shore Model 455 Gaussmeter User s Manual 2 2 FLUX DENSITY OVERVIEW 2 2 1 What is Flux Density A magnetic field can be envisioned as consisting of flux lines i A unit of flux is called a line In the cgs system one line of flux equals one maxwell Mx In the SI system the flux unit is the weber Wb where 1W
19. Register Clear Methods Operation Event Register Send CLS Register Method Example Condition Registers None registers are not latched Event Registers Query the event register ESR clears Standard Event Status register Standard Event Status Register CLS clears both registers Power on instrument Enable Registers Standard Event Status Enable Register Operation Event Enable Register Service Request Enable Register Write 0 to the enable register ESE 0 clears Standard Event Status Enable register Power on instrument Status Byte There are no commands that directly clear the Status Byte as the bits are non latching To clear individual summary bits clear the event register that corresponds to the summary bit Sending CLS will clear all event registers which in turn clears the status byte If bit 5 ESB of the Status Byte is set send ESR to read the Standard Event Status Register and bit 5 will clear Power on instrument 6 6 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual 6 1 4 2 Status Register Sets As shown in Figure 6 1 there are two register sets in the status system of the Model 455 Standard Event Status Register and Operation Event Register 6 1 4 2 1 Standard Event Status Register Set The Standard Event Status Register reports the following interface related instrument events power on detected command synt
20. Rotate the fuse holder until the proper voltage indicator shows through the window Verify the proper fuse value Re assemble the line input assembly in the reverse order SE SOW e Da Verify the voltage indicator in the window of the line input assembly Connect the instrument power cord kent ke ro Turn the line power switch On I Power Switch O Off On Line Cord Input Fuse Drawer Ny LINE 10 6 Voltage 50 60 Hz 40 VA MAX 100 120 V 0 5A 5x20mmT 220 240 V 0 25 A 5 x 20 mm T 455_Power bmp Figure 8 2 Power Fuse Access 8 5 FUSE REPLACEMENT Use the following procedure to remove and replace the line fuses WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power before performing these procedures CAUTION For continued protection against fire hazard replace only with the same fuse type and rating specified for the line for the line voltage selected 8 2 Service Lake Shore Model 455 Gaussmeter User s Manual Fuse Replacement Continued NOTE Test fuse with an ohmmeter Do not rely on visual inspection of fuse Locate line input assembly on the instrument rear panel See Figure 8 2 With a small screwdriver release the drawer holding the line voltage selector and fuses Remove and discard both existing fuses Replace with proper Slow Blow time delay fuse ratings as follows 1 2 Turn power switch Off O
21. The setting range is from 0 to 100 if unipolar or from 100 to 100 if bipolar with a setting resolution of 0 001 A value of 100 represents an output of 10 V and a value of 100 represents an output of 10V The manual entry screen appears as a prompt for setting the Analog Output 3 voltage Use the data entry keys to enter the manual output value between 0 and 100 unipolar or 100 and 100 bipolar Press Enter to accept the new value and return to the normal display Press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display 4 24 Operation Lake Shore Model 455 Gaussmeter User s Manual 4 12 2 Analog Output 3 Polarity The Analog Output 3 can be configured to operate either in a unipolar fashion output from 0 volts to 10 volts or in a bipolar fashion output from 10 volts to 10 volts To configure the Analog Output 3 polarity press and hold the Analog key for approximately 4 seconds The following screen appears as a prompt for configuring the polarity Use the A org key to select from Unipolar or Bipolar Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display 4 12 3 Analog Output 3 Volt limit In some instances it may be desirable to limit the maximum voltage of the Analog Output 3 for examp
22. User Programmable Cable Continued If a valid HMCBL cable is attached the next MCBL Program screen appears as a prompt for serial number entry Use the number entry keys to enter the numeric serial number up to 10 digits Press Enter to accept the new value and continue to the next setting screen If desired press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display The next MCBL program screen appears as a prompt for entering the nominal sensitivity in mV kG This sensitivity is based on a 100 mA Hall current Use the data entry keys to enter the nominal sensitivity value from one of the following ranges between 0 550 and 1 100 mV kG between 5 500 and 11 000 mV kG and between 550 and 1100 mV kG Press Enter to accept the new value and return to the normal display If desired press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display The Model 455 will adjust the available ranges based on the values entered for the current and sensitivity NOTE Using a sensitivity outside the above ranges may cause reduced performance Values near but lower than the 55 minimum will reduce resolution Values near but above the 11 maximum may cause an instrument overload OL condition before full scale range is reached Hence using Hall gene
23. charge between bodies at different electrostatic potentials caused by direct contact or induced by an electrostatic field The low energy source that most commonly destroys Electrostatic Discharge Sensitive ESDS devices is the human body which generates and retains static electricity Simply walking across a carpet in low humidity may generate up to 35 000 volts of static electricity Current technology trends toward greater complexity increased packaging density and thinner dielectrics between active elements which results in electronic devices with even more ESD sensitivity Some electronic parts are more ESDS than others ESD levels of only a few hundred volts may damage electronic components such as semiconductors thick and thin film resistors and piezoelectric crystals during testing handling repair or assembly Discharge voltages below 4000 volts cannot be seen felt or heard 8 7 1 Identification of Electrostatic Discharge Sensitive Components The following are various industry symbols used to label components as ESDS ax CAUTION Wy ij Ewe 8 7 2 Handling Electrostatic Discharge Sensitive Components Observe all precautions necessary to prevent damage to ESDS components before attempting installation Bring the device and everything that contacts it to ground potential by providing a conductive surface and discharge paths As a minimum observe these precautions De energize or disconnect all power and signal sources and load
24. dis 0125 40 020 D Model a atiwe Stem Frequency SE em perature Coefficient max Wo area Material Range nau Feri HMFA 18 oil mn 0 dia Node DC to Lento 20kG oC to Tubing amp HSE se eM IT ee Was T815 UF 0 5 mar Beds approx 10 KHz eee SN 35 KG TSC Al minu m Flexible_Axial eps Figure 7 8 Definition of Lake Shore Flexible Axial Probe 7 8 Probes and Accessories 7 4 PROBE ACCESSORIES Additional accessories are available that may be desirable A list of accessories available for magnetic systems is as follows Lake Shore Model 455 Gaussmeter User s Manual Description Of Accessories Probe Extension Cables Four cable lengths are available Each extension cable contains an EEPROM for calibration data To maintain probe accuracy the probe and extension cable must be calibrated together at Lake Shore however probes may be matched to uncalibrated extension cables in the field Refer to Section 5 1 The probe will exhibit its full accuracy if used without the extension cable Part numbers and cables lengths are defined as follows HMCBL XX MH XxX MRA XXX MRT XXX Calibrated HMPEC 10 HMPEC 25 HMPEC 50 HMPEC 100 Uncalibrated HMPEC 10 U HMPEC 25 U HMPEC 50 U HMPEC 100 U Description Probe Extension Cable Probe Extension Cable Probe Extension Cable Probe Extension Cable Length 3 meters 10 feet 8 meters 25 feet 15 meters 50 feet 30 meters 100 feet Hall
25. many advanced features at a moderate price DSP technology creates a solid foundation for accurate stable and repeatable field measurements Advanced features including DC to 20 kHz AC frequency response peak field detection to 50 us pulse widths DC accuracy of 0 075 and up to 5 digits of display resolution make the Model 455 ideal for both industrial and research applications For added functionality and value the Model 455 includes a standard Lake Shore Hall probe DC Measurement Mode Static or slowly changing fields are measured in DC mode In this mode the Model 455 takes advantage of the internal auto zero function and probe linearity compensation to provide a basic DC accuracy of 0 075 Measurement resolution is enhanced by advanced signal processing capability allowing users the choice of reading rates to 30 readings per second or high resolution to 5 digits Front end amplification specifically designed to complement DSP data acquisition provides high stability and repeatability That along with probe temperature compensation provides superior stability ideally suited for demanding DC measurement applications such as field mapping LakeShore 455 DSP Gaussmeter Relative Alarm Remote e e f pe RMS Sai e Analog Zero Max l Local Output Display Autorange Probe Escape Hold Peak E 9 9 9 9 9 9 9 Select Interface Alarm Relay Units Range Probe Enter Relative Reset Te E 9 9 Wi oe 455_Front bmp Figure
26. 000 uT 350 00 mOe 28 000 A m 35 000 mG 3 5000 uT 35 000 mOe 2 8000 A m For manual ranging press the Select Range key The screen appears as a prompt for changing the range Use the A or V key to select from the available ranges Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display NOTE The Auto Range function is not offered for Peak Pulse measurements 4 16 Peak Operation Operation Lake Shore Model 455 Gaussmeter User s Manual 4 8 2 Peak Operation Periodic Pulse Setup The Peak measurement mode can be configured to measure pulsed fields or the maximum amplitude of periodic fields In periodic mode the instrument follows the peak amplitude of the periodic signal This may be useful in determining additional information about AC fields such as crest factor Pulsed fields with a minimum pulse width of 50 us can be captured using the pulse measurement mode Once captured these readings will only change if a larger peak is measured or if the Reset key is pressed To setup the periodic or pulse feature press and hold the Peak key for approximately 4 seconds The Peak configuration screen appears as a prompt for selecting Periodic or Pulse measurements Use the A or F key to select from Periodic or Pulse Press Enter to accept the new selection and continue to the next setti
27. 16 6 2 SERIAL INTERFACE OVERVIEW riara iiien a aie A e E A Aa 6 17 6 2 1 Changing Baud Raters iiaiai paata aiaa i rina 6 17 6 2 2 Physical Connection 2220 aie a Gna ee 6 17 6 2 3 Hardware UDO reiege REENEN EES 6 18 6 2 4 Character FOrmativistcccdiveteccivisvncedvyueeia ege deeg ed deg 6 18 6 2 5 Message String EE 6 18 6 2 6 Message Flow Control 6 19 6 2 7 Serial Interface Example Programs ssssssseesseesseesissiettinsttntttnttnuttnntttnnttnntnnnnnntn nenn nnna 6 19 6 2 7 1 Visual Basic Serial Interface Program Getup 6 20 6 2 7 2 Program Operation s ncines ante e ai Geena ene tee deeds 6 23 6 2 8 FROUDIGSMOOUIAG EE 6 23 6 3 COMMAND SUMMARY veccecuseticestentdcedeseseeds cand savaestivesecsndsedassseedavsceddausccdichesveddedacsstedaasesdeacs 6 24 6 3 1 Interface Commands Alphabetical Listing ccccceecceceeeeeeeeeeeeeeeseeeeeseaeeesaeeeeaeeesaees 6 26 Table of Contents iii Lake Shore Model 455 Gaussmeter User s Manual TABLE OF CONTENTS Continued Chapter Section Title Page 7 PROBES AND ACCESSORIES sscccesecssseeeeseeeeeeeseseaeseseeeenseaeensesesaesaseaesnseaeseaeseseaesesnaneesneess 7 1 7 0 GENERAL en aceesat bovis ated eet tee deeaie bettie a ae eege 7 1 7 1 MODELS arrears deed AE eege eege 7 1 7 2 EE EREM tin ee S ed tie ted ede eee el E 7 1 7 3 LAKE SHORE STANDARD DROBES scenes ceaeeeseaeeeeeeeseeeeesaeeesaeeeeeeeseas 7 2 7 3 1 Hall Probe Selection Criteria cccccecccseee
28. 2 EE CAL Calibration Error NRDG New Field Reading ALRM Alarm OVLD Field Overload NPRB No Probe Figure_6 1 bmp Figure 6 1 Model 455 Status System Remote Operation 6 5 6 1 4 1 5 Reading Registers Lake Shore Model 455 Gaussmeter User s Manual Any register in the status system may be read using the appropriate query command Some registers clear when read others do not Refer to Section 6 1 4 1 7 The response to a query will be a decimal value which corresponds to the binary weighted sum of all bits in the register refer to Table 6 1 The actual query commands are described later in this section Table 6 1 Binary Weighting of an 8 Bit Register Position B7 B6 BS B4 B3 B2 B1 BO Decimal 128 64 32 16 8 4 2 1 Weighting 27 26 25 24 23 22 2 20 Example If bits 0 2 and 4 are set a query of the register will return a decimal value of 21 1 4 16 6 1 4 1 6 Programming Registers The only registers that may be programmed by the user are the enable registers All other registers in the status system are read only registers To program an enable register send a decimal value which corresponds to the desired binary weighted sum of all bits in the register refer to Table 6 1 The actual commands are described later in this section 6 1 4 1 7 Clearing Registers The methods to clear each register are detailed in Table 6 2 Table 6 2
29. 3 5 2 1 User Programmable Cables esnan ninan iser aaraa aaa a a aa E AAE EADAE LA aa 5 3 5 2 2 Ohms Measurement Mode assrar ii tessar i raa era S EA R AEAEE EEEE NAAA AEAEE RE A 5 4 6 COMPUTER INTERFACE OPERATION cccccsseeeeeseseeeeeesecesesesceeseseseeeseseeeeneeseseeesensseeees 6 1 6 0 GENERAL rroi ira A E SETAE AE EE A 6 1 6 1 IEEE 488 INTERFACE rirse eena aa a EAS ee a Ea SE E A AS 6 1 6 1 1 Changing IEEE 488 Interface Parameters ccccccccceeceeseceeeeeeeaeeeeeaeseeeeeseaeeesaeeseneeseaees 6 2 6 1 2 Remote Local Operation 6 2 6 1 3 IEEE 488 Command Structure oinas ire aei iaaea PLA EAA E AA E a 6 2 6 1 3 1 Bue Control Command i esiones eii ere EEEE a EN ne Ea EE Ee Ne EE EEA 6 2 6 1 3 2 GOMIMON GOMMANS TEE 6 3 6 1 3 3 Device Specific COMMANAS EE 6 3 6 1 3 4 On ue EE 6 3 6 1 3 5 Highspeed Binary Output Configuration ececececeeeeeeeeeeeeeeeeeceeeeeeeeeseaeeeaeeseaeeeaeeseaeessaeeseaeeeaees 6 4 6 1 4 Status System nade nee aan Oh aes tine BA eee eau a 6 5 6 1 4 1 WU 6 5 6 1 4 2 Status Register Sets n saves t elei derbei db ee deele 6 7 6 1 4 3 Status Byte and Service Request GO 6 9 6 1 5 IEEE Interface Example Progorams 6 11 6 1 5 1 IEEE 488 Interface Board Installation for Visual Basic Program ceeesseeeeeeneeeteseeeeeeeneeeeeee 6 12 6 1 5 2 Visual Basic IEEE 488 Interface Program Getup 6 13 6 1 5 3 Program Qperation EAEE sees Ee dee Eed eebe EERSTEN 6 16 6 1 6 TroubleShOoting EE 6
30. 4E02 VF 2 0 125 o 045 HMNT4EO2VF 0 0490 130 DC 30 35 kG HMNT 4E04 VF 4 0 125 Max 0 005 i 0 25 dia 0 210 Stainless 800 Hz 2 to 1 5K to 0 010 3160 WN 61 1 GE DM 0 010 0 050 Tue 350k per C a One probe is included with the purchase of the Model 455 Model numbers shown in bold are the probes available to chose from Transverse bmp Figure 7 4 Definition of Lake Shore Transverse Probes TANGENTIAL PROBE Cable length 6 6 feet 0 36 0 030 dia actus Stem Freq C omede d Temp eratu re Contain i Coefficient Max i S Srea Mater Range Ty Geess Max Mperature EH Sensor 0 030 0 020 dia 8 Mak max Hiig pe HSE DO3 TH 0 125 Tangential eps Figure 7 5 Definition of Lake Shore Tangential Probe 7 6 Probes and Accessories Lake Shore Model 455 Gaussmeter User s Manual AXIAL PROBES a B S Cable Length 6 6 feet 0 36 40 030 dia D Active Stem Freq Corrected O Temp Coefficient Max Contain L A Area Material R Accuracy Temp Temp aterial RANJE Reading Range Zero Calibration gon cor HMMA 0602 TH 2 0 125 HMMA 0604 TH 4 0 125 ia DC to HMMA 0608 TH 8 0 125 400 Hz HMMA 0618 TH 18 0 12 0 020 Alum 0 25 DC to 20 kG 2 0 125 HMNA 1904 VR 4 0 125 ia pee Dele 0 003 20 kHz HMNA 1908 VR 8 0 125 0 20 p 0 C HMMA 1802 VR 2 0 063 to 30 kG to 009G 0 015 HMMA 1808
31. 7 3 8 4 1 4 2 6 1 6 2 6 3 6 4 6 5 6 6 7 1 7 2 7 3 7 4 7 5 7 6 7 7 7 8 7 9 7 10 7 11 7 12 7 13 7 14 7 15 7 16 7 17 7 18 8 1 8 2 8 3 8 4 8 5 8 6 8 7 Lake Shore Model 455 Gaussmeter User s Manual LIST OF ILLUSTRATIONS Title Page Model 455 Front Panels inyin erener aae a eA aa a a ue a e a Wee 1 1 Model 455 System Block Diagram ccccecccsesceceneeeeseeeeneeecaeeeseeessaeeesaeessaeeesaeesaeeesaeesaeesaeeseaeeeaeeseaeeeaees 2 2 DC Measurement Block Diagram ecceeeceeseceeeeeeeseeeeeeeeteaeeeeeeesaeeeeeesaaeeeeaeeseaeeseaeeseaeeseaeeseaeeseaeeseaeeeeaeetes 2 3 RMS Narrow Band AC Block Diagram cccccceeeeeeeeeeeeeeteaeeeeaeeteaeeeeaeeseaeeseaeeseaeeseaeeseaeeseaeeseaeeseaeeseneeseatenes 2 3 RMS Wide Band AC Block Diagoram nennen aneneen 2 3 Peak Measurement Block Diagram AA 2 3 Hall Generator THeOry atic nian eee dete ate epee seein ea orate anda EE ened ae ae ed 2 5 Axial and Transverse Eenelter 2 6 Model 455 Rear Panels ugesot alten ee eatin ib a ae ee ee ee 3 2 Eine liput Assembly cicien aeaaea ioen aa ara a ea aa E EAE AN AAE Eaa Spa apren he Saa a aanp R Eana Pa aaeeea oiai 3 3 Maximum Flexible Probe Bend PHadus AA 3 5 Probe Orientation For Positive Measurement ccceeeeeceeeeeeeeeeeneeeeaeeteaeeseaeeseaeeseaeeseaeeseaeeseaeeseaeeseeeseaeene 3 5 Effect Of Angle On Measuremente AAA 3 6 Auxiliary l Connector egene cdebett See he a a etal ede hited bie ee teeta ede eee ed 3 7
32. 7 2 16 Press Enter or select the Send button with the mouse to send command 17 Type Exit and press Enter to quit Remote Operation 6 21 Lake Shore Model 455 Gaussmeter User s Manual Table 6 8 Visual Basic Serial Interface Program Public gSend As Boolean Global used for Send button state Private Sub cmdSend_ Click gSend True End Sub Routine to handle Send button press Set Flag to True Private Sub Form Load Dim Dim Dim Dim Dim strReturn As String strHold As String Term As String ZeroCount As Integer strCommand As String frmSerial Show Term Chr 13 amp Chr 10 ZeroCount 0 strReturn strHold mn If frmSerial MSComm1 PortOpen True Then End frmSerial MSComm1 PortOpen False If frmSerial MSComm1 CommPort 1 frmSerial MSComml1 Settings 9600 0 7 1 frmSerial MSComml1 InputLen 1 frmSerial MSComm1 PortOpen True Do Do DoEvents Loop Until gSend True gSend False strCommand frmSerial txtCommand Text strReturn strCommand UCase strCommand If strCommand EXIT Then End End If frmSerial MSComml1 Output strCommand amp Term If InStr strCommand lt gt 0 Then End Loop While ZeroCount lt 20 And strHold lt gt Chr 10 If frmSerial MSComml1 InBufferCount frmSerial Timerl Enabled True Do DoEvents Main code section Used to return response Temporary character space Terminato
33. 8 3 Location Of Important Internal Components U16 Main Firmware EPROM Switch1 PCB Layout bmp 8 6 Service Lake Shore Model 455 Gaussmeter User s Manual Firmware Replacement Continued CAUTION The ICs are Electrostatic Discharge Sensitive ESDS devices Wear shock proof wrist straps resistor limited to lt 5 mA to prevent injury to service personnel and to avoid inducing an Electrostatic Discharge ESD into the device Use IC puller to remove existing IC from the socket Noting orientation of new IC use an IC insertion tool to place new device into socket KS Ceara C TIH Y Karl om nee on i Site Typical IC Eprom eps 5 Follow the top of enclosure INSTALLATION procedure in Section 8 8 8 10 CONNECTOR AND CABLE DEFINITIONS The AUXILIARY I O PROBE INPUT SERIAL I O DTE and IEEE 488 INTERFACE connectors are defined in Figures 8 4 thru 8 7 AUXILIARY UO Auxiliary_lO bmp Pin Description Pin Description 1 Analog Out 1 14 Ground 2 Analog Out 2 15 Ground 3 Analog Out 3 16 Ground 4 No Connection 17 No Connection 5 Internal Use Only 18 No Connection 6 Internal Use Only 19 No Connection 7 No Connection 20 No Connection 8 Relay 1 NO 21 No Connection 9 Relay 1 COM 22 No Connection 10 Relay 1 NC 23 No Connection 11 Relay 2 NO 24 No Connection 12 Relay 2 COM 25 No Connection 13 Relay 2 NC Figure 8 4 AUX
34. Auto Range Query Input AUTO term Returned lt off on gt term Format n Refer to command for description BAUD RS 232 Baud Rate Command Input BAUD lt bps gt term Format n lt bps gt 1 9600 Baud 2 19200 Baud 3 38400 Baud 4 57600 Baud BAUD RS 232 Baud Rate Query Input BAUD term Returned lt bps gt term Format n Refer to command for description BEEP Alarm Beeper Command Input BEEP lt state gt term Format n lt state gt 0 Off 1 On Remarks Enables or disables system beeper sound when an alarm condition is met BEEP Alarm Beeper Query Input BEEP term Returned lt state gt term Format n Refer to command for description BRIGT Display Brightness Command Input BRIGT lt bright gt term Format n lt bright gt 1 25 2 50 3 75 4 100 Default 3 Remote Operation 6 29 Lake Shore Model 455 Gaussmeter User s Manual BRIGT Display Brightness Query Input BRIGT term Returned lt bright gt term Format n Refer to command for description DFLT Factory Defaults Command Input DFLT 99 term Remarks Sets all configuration values to factory defaults and resets the instrument The 99 is included to prevent accidentally setting the unit to defaults DISPLAY Display Configuration Command Input DISPLAY lt item gt term Format n lt item gt Specifies the item to display on line 2 1 4 1 Blank 2 Field 3 Probe Temperature and Frequency
35. Enabled False End Sub Routine to handle Timer interrupt Turn off timer 6 22 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual 6 2 7 2 Program Operation Once the example program is running try the following commands and observe the response of the instrument Input from the user is shown in bold and terminators are added by the program The word term indicates the required terminators included with the response ENTER COMMAND IDN Identification query Instrument will return a string identifying itself RESPONSE LSCI MODEL455 1234567 02032003 term ENTER COMMAND RDGFIELD Field reading query Instrument will return a string with the present field reading in the present units RESPONSE 273 150E 00 term ENTER COMMAND RANGE 1 Field range command Instrument will set to the lowest range No response will be sent ENTER COMMAND RANGE Field range query Instrument will return a string with the present field range setting RESPONSE 1 term ENTER COMMAND RANGE 5 RANGE Field range command followed by a query Instrument will change to the highest range setting then return a string RESPONSE 5 term with the present setting The following are additional notes on using either Serial Interface program Ifyou enter a correctly spelled query without a nothing will be returned Incorrectly s
36. H E Disk drives y National Instruments GPIB Interfaces w Display adapters Floppy disk controllers Hard disk controllers ee Keyboard Monitor A Mouse National Instruments GPIB Interface p m DEV12 Attributes 89 Network adapters 4018 1 Ports COM amp LPT Interface Termination Methods m Timeouts zB System devices leen DI M Send EOI at end of write 0 F TeminateReadon os Dis z GPIB Address See a Serial Poll Primary V Set EO with EOS on Write ba il Pad sec k fi2 D ue Properties Refresh R I 8 bit EOS Compare Secondary NONE fio EOS Byte M Readdress Figure 6 6 DEV 12 Device Template Configuration 6 12 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual 6 1 5 2 Visual Basic IEEE 488 Interface Program Setup This IEEE 488 interface program works with Visual Basic 6 0 VB6 on an IBM PC or compatible with a Pentium class processor A Pentium 90 or higher is recommended running Windows 95 or better It assumes your IEEE 488 GPIB card is installed and operating correctly refer to Section 6 1 5 1 Use the following procedure to develop the TEEE 488 Interface Program in Visual Basic Start VB6 Choose Standard EXE and select Open Resize form window to desired size Fe ton On the Project Menu select Add Module select the Existing tab then navigate to the location on your computer
37. International Electrotechnical Commission IEC safety standards Ventilation The instrument has ventilation holes in its side covers Do not block these holes when the instrument is operating Do Not Operate In An Explosive Atmosphere Do not operate the instrument in the presence of flammable gases or fumes Operation of any electrical instrument in such an environment constitutes a definite safety hazard Keep Away From Live Circuits Operating personnel must not remove instrument covers Refer component replacement and internal adjustments to qualified maintenance personnel Do not replace components with power cable connected To avoid injuries always disconnect power and discharge circuits before touching them Do Not Substitute Parts Or Modify Instrument Do not install substitute parts or perform any unauthorized modification to the instrument Return the instrument to an authorized Lake Shore Cryotronics representative for service and repair to ensure that safety features are maintained Cleaning Do not submerge instrument Clean only with a damp cloth and mild detergent Exterior only 1 4 SAFETY SYMBOLS Direct current power line Equipment protected throughout by IO double insulation or reinforced insulation equivalent to Class II of Alternating or direct current power line IEC 536 see Annex H Alternating current power line Three phase alternating current power line A Caution High voltages danger of elect
38. Introduction Lake Shore Model 455 Gaussmeter User s Manual Instrument Probe Features Continued Probe Information The gaussmeter reads the probe information on power up or any time the probe is changed to allow hot swapping of probes Critical probe information can be viewed on the front panel and read over the computer interface to ensure proper system configuration Extension Cables The complex nature of Hall effect measurements make it necessary to match extension cables to the probe when longer cables are needed Keeping probes and their extensions from getting mixed up can become a problem when more than one probe is in use The Model 455 alleviates most of the hassle by allowing users to match probes to extensions in the field Stored information can be viewed on the front panel and read over the computer interface to ensure proper mating Hall Effect Generators Magnetic Field Sensors The Model 455 will operate with a discrete Hall effect generator when a suitable probe is not available Users can program nominal sensitivity and serial number into an optional HMCBL 6 blank connector to provide all gaussmeter functions except field and temperature compensation If no sensitivity information is available the Model 455 reverts to resistance measurement 1 1 3 Display and Interface Features Display The Model 455 has a 2 line by 20 character vacuum fluorescent display During normal operation the display is used to report field readi
39. Model 455 Gaussmeter User s Manual Electromagnetic Compatibility EMC for the Model 455 Gaussmeter Electromagnetic Compatibility EMC of electronic equipment is a growing concern worldwide Emissions of and immunity to electromagnetic interference is now part of the design and manufacture of most electronics To qualify for the CE Mark the Model 455 meets or exceeds the requirements of the European EMC Directive 89 336 EEC as a CLASS A product A Class A product is allowed to radiate more RF than a Class B product and must include the following warning WARNING This is a Class A product In a domestic environment this product may cause radio interference in which case the user may be required to take adequate measures The instrument was tested under normal operating conditions with a probe and interface cables attached If the installation and operating instructions in the User s Manual are followed there should be no degradation in EMC performance This instrument is not intended for use in close proximity to RF Transmitters such as two way radios and cell phones Exposure to RF interference greater than that found in a typical laboratory environment may disturb the sensitive measurement circuitry of the instrument Pay special attention to instrument cabling Improperly installed cabling may defeat even the best EMC protection For the best performance from any precision instrument follow the installation instructions in the User
40. Model RM Rack Mount Kit P N 4022 3 8 Model RM2 Dual Rack Mount Shelf P N A0 206 3 9 Model 455 Front Panel us menn rnea yiera paoe senate he vein oth ORG deg dE EN 4 1 Front Panel Display Definition 55 2 c6 cdesgevtsdaccesndececinacecdiesuceehdesgecdaetecsecdesabbeaedshhaeaddeseaanstesdneaiacsaaeaddsphaesdees 4 2 Model 455 Status Syste Msie nieni hos hoc aie oe nie ee Eggs Ee 6 5 Standard Event Status Register eu ci ide enh ate a T S A dee 6 7 Operation Event Register vs isa seen er ae aie td ei eee eh A Been he a ee Bs 6 8 Status Byte Register and Service Request Enable Register c ccecceesceeeneeeeeeeeeneeeeeeeeeeeeeeeeeeneeeeeeeeeaes 6 9 GPIBO Setting Configuration 2 0 8 t ee Bie ean ein eden ends ite hha eke 6 12 DEV 12 Device Template CGonfouraton 6 12 Effect Of Angle On Measuremente 11 7 4 Definition of Lake Shore Gamma Probe cecceesceeeeeeeeeeeeeaeeeeaeeteaeeeeaeeseaeeeeaeeseaeeseaeeseaeeseaeeseeessaeeseneeseaeere 7 5 Definition of Lake Shore Robust Brass Stem Transverse Probes 7 5 Definition of Lake Shore Transverse Probes AA 7 6 Definition of Lake Shore Tangential Probes AAA 7 6 Definition of Lake Shore Axial Probes AAA 7 7 Definition of Lake Shore Flexible Transverse PDrobes AAA 7 8 Definition of Lake Shore Flexible Axial Probes AAA 7 8 Model HMCBL XX User Programmable Cable Accessory c ccesceeeceeeeeeeeneeeeeeeeeeeeeeeeeeeeneeseeeeeneeeaes 7 11 Transverse Hall Generator HGT 3010
41. Nominal control current Icy 100 mA 100 mA Maximum continuous current 300 mA 300 mA non heat sinked Magnetic sensitivity Ic nominal control 0 55 to 1 05 mV kG 0 55 to 1 05 mV kG current Zero field offset voltage Ic nominal control 200 uV max 200 uV max current Operating temperature range 1 5 K to 375 K 1 5 K to 375 K Mean temperature coefficient of magnetic 0 01 K approx 0 01 K approx sensitivity Mean temperature coefficient of offset Ic 0 4 uV K max 0 4 uV K max nominal control current Mean temperature coefficient of resistance 0 6 K max 0 6 K max 34 AWG copper w Teflon insulation 34 AWG copper w Teflon insulation Maximum linearity error 1 0 RDG 30 to 30 kG 1 0 RDG 30 to 30 kG sensitivity vs field 2 0 RDG 150 to 150 kG 2 0 RDG 150 to 150 kG 7 12 Probes and Accessories Lake Shore Model 455 Gaussmeter User s Manual 10 mn mb eg in 0 20in amten 4 O gt OE GE E Be 0 20 in diameter C 455 C 5 eps Figure 7 11 Axial Hall Generator HGA 3010 HGA 3030 and HGCA 3020 Dimensions 0 105 mea Table 7 2 Axial Hall Generator Specifications HGA 3010 HGA 3030 Description Instrumentation quality axial low Instrumentation quality axial phenolic temperature coefficient phenolic package package Active area approximate 0 030 inch diameter circle 0 030 inch diameter circle Nominal control current Icy 100 mA 100 mA Maxim
42. Object dropdown list select General Add the statement Public gSend as Boolean Double Click on cmdSend Add code segment under Private Sub cmdSend_Click as shown in Table 6 8 In the Code Editor window under the Object dropdown list select Form Make sure the Procedure dropdown list is set at Load The Code window should have written the segment of code Private Sub Form_Load Add the code to this subroutine as shown in Table 6 8 Double Click on the Timer control Add code segment under Private Sub Timer1_Timer as shown in Table 6 8 Make adjustments to code if different Com port settings are being used a e Lake Shore Model 455 Gaussmeter User s Manual Table 6 7 Serial Interface Program Control Properties Current Name Property New Value Label Name IbIExitProgram Caption Type exit to end program Label2 Name lblCommand Caption Command Label3 Name lblResponse Caption Response Textl Name txtCommand Text lt blank gt Text2 Name txtResponse Text lt blank gt Command1 Name cmdSend Caption Send Default True Form Name frmSerial Caption Serial Interface Program Timer Enabled False Interval 10 13 Save the program 14 Run the program The program should resemble the following i Serial Interface Program Type exit to end program Commang Response eg Biel E 15 Type in a command or query in the Command box as described in Section 6 2
43. Sage accuracy Temperature Maxmum Temperature 3 tamadni Range Sensor HALA es DC to ach A2 0 Cp S Suu5 HI 0 0 SE le Ou HS als 2 gauss h CG EES E E Gamma eps Figure 7 2 Definition of Lake Shore Gamma Probe ROBUST BRASS STEM TRANSVERSE PROBES E 5 a e a T 20 dia T j Tempermture Coeficient Contain AGGUTEGy Maximum SI perature ido Ten dng Calibration Sensor ae 202 to Su kG and LS GE OTS a 286 fi ddh 30 35 kG el in dia Eass OC EN Wes TEY KU Sch to 30 kG es a8 HSTAl and eiii GI 0 005 t 20 15 seated ioe j 0 6 KG dit SOEN Brass_Transverse eps Figure 7 3 Definition of Lake Shore Robust Brass Stem Transverse Probes Probes and Accessories 7 5 Lake Shore Model 455 Gaussmeter User s Manual TRANSVERSE PROBES B es 2 5 T Cable length 6 6 feet 0 36 0 030 dia Corrected Op Temperature Contain Active Stem Freq ag Model No L T W A Aea idaterial Range Type Accuracy Temp Coefficient Max Temperature 9 of rdg Range Zero Calibration Sensor HMMT 6J02 VR 2 0 125 SE DC HMMT 6J04 VR 4 0 125 a4 0 180 A 0 20 HMMT 6J08 VR 8 0 125 max 0 005 800 He Ge HSE and HMMT 6J18 VR 18 0 25 fob U o DC to l 20 kHz HMNT 4E02 VR 220 125 o 04s 0 150 30 35 kG max 0 005 0 061 0 180 max 0 005 HMMT 6J18 VF 18 0 125 DC is 0 10 Se to 30 kG HST 4 and 0 15 HMNT
44. Status Enable Query OPSTE term lt bit weighting gt term nnn Refer to Section 6 1 4 2 2 for a list of operational status bits Operational Status Register Query OPSTR term lt bit weighting gt term nnn The integers returned represent the sum of the bit weighting of the operational status bits These status bits are latched when the condition is detected This register is cleared when it is read Refer to Section 6 1 4 2 2 for a list of operational status bits Peak Hold Reset Command PKRST term Resets the stored positive and negative peak field readings and sets them equal to zero This is only valid in Pulse measurement mode PRBFCOMP Probe Field Compensation Command Input PRBFCOMP lt off on gt term Format n lt off on gt Specifies Probe Field compensation off or on Valid entries 0 off 1 on Example PRBFCOMP 1 term Field Measurement uses the Probe Field Compensation table PRBFCOMP Probe Field Compensation Query Input PRBFCOMP term Returned lt off on gt term Format n Refer to command for description 6 32 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual PRBSENS Probe Sensitivity Query Input PRBSENS term Returned lt sensitivity gt term Format tnnn nnnEtnn Remarks Returns the probe sensitivity in mV kG PRBSNUM Probe Serial Number Query Input PRBSNUM term Returned lt type gt term Format XXXXXXXXXX Remarks Returns th
45. VE 61 mm 2 4 ind Figure 7 17 Model 4060 Zero Gauss Chamber 4060_Chamber eps Frout yew 19mm 08 in e diameter opening 7 2mm T 23 in 318 mm 1 3 in F 524 mm OG In 304 8 mm izin Depth of Opening 279 4 mm 11 in ENEE i D i D S Oe Wew 4065_Chamber eps Figure 7 18 Model 4065 Large Zero Gauss Chamber 7 18 Probes and Accessories Lake Shore Model 455 Gaussmeter User s Manual CHAPTER 8 SERVICE 8 0 GENERAL This chapter provides basic service information for the Model 455 Gaussmeter Customer service of the product is limited to the information presented in this chapter Factory trained service personnel should be consulted if the instrument requires repair 8 1 CONTACTING LAKE SHORE CRYOTRONICS If a Lake Shore product was purchased through a dealer or representative please use that resource for prompt sales or service information When contacting Lake Shore directly please specify the name of a department if do not know the name of an individual Questions regarding product applications price availability and shipments should be directed to sales Questions regarding instrument calibration or repair should be directed to instrument service Do not return a product to Lake Shore without an RGA number Refer to Section 8 2 Contact information may change periodically but current contact information can always be found on the Lake Shore web site www lakeshore com Lake Shore Cry
46. VR 8 0 125 gia 75 C per c per C HMMA 1818 VR 18 0 25 DC to 025 Alum 30 35 kG HMMA 1836 VR 36 0 25 10 kHz HMMA 2502 VR 2 0 063 0 25 dia g s HMMA 2508 VR 8 0 125 0 006 dia y es HMNA 1902 VF 220 125 9 497 approx 4 0 125 de E SS wf td z Seel 0 005 0 10 2 0 063 Se 8 40 125 dia ae 18 0 25 Bee 30 35 kG 36 0 25 2 0 063 0 25 dia 0 015 a 0 125 0 006 0 005 8 0 125 1 to 0 25 di 100 kG 36 0 25 lt 1A 0 006 7 Stainless i 0 60 0 50 0 25 dia 0 025 g ie 15K to 0 006 0 005 100 kG 350 K One probe is included with the purchase of the Model 455 Model numbers shown in bold are the probes available to chose from Axial bmp 0 13 G per C No dia HMMA 0802 UH 2 0 125 0 080 approx HMMA 0804 UH 4 0 125 dia HMMA 0808 UH 8 0 125 0 005 HMNA 1902 VR HMNA 1904 VF HMNA 1908 VF HMMA 1802 VF HMMA 1808 VF HMMA 1818 VF HMMA 1836 VF HMMA 2502 VF HMMA 2508 VF HMMA 1808 WL HMMA 2536 WL HMCA 2560 WN gene 20 126 EE RUE Men 420125 HMMA o808 uH 8 20 126 EE Baus vam RE RN E BR EE EE RE Ke E BR EE KENE Bgum 4 20 128 HMNA 1908VF 8 20 125 RE E GE KSE HMMA 1836 VF 36 20 2 EE HMA 2508 VF ae Figure 7 6 Definition of Lake Shore Axial Probes Probes and Accessories 7 7 Lake Shore Model 455 Gaussmeter User s Manual FLEXIBLE TRANSVERSE PROBES
47. a choice of AC wide band or narrow band modes The components that are used in analog signal processing can have different values from component to component and are temperature dependent Using Digital Signal Processing gives better measurement repeatability and increases the temperature stability of the instrument 2 1 3 Limitations of Sampled Data Systems Sampled data systems do have their limitations but if they are understood they can be dealt with easily The limitations of sampled data systems come from the fact that a continuous analog signal is being sampled and digitized This inherently limits the frequency of the signal that can be read as well as the resolution at which it can be read Typically the resolution is high enough and enough averaging is done that it does not present a problem The frequency limitation can cause unique problems There are notches in the frequency response as the input signal approaches one half the sampling rate and its harmonics As the measured signal approaches these harmonic frequencies the reading will fall off due to the null in the filter The rate at which an analog signal must be sampled depends on the frequency content of the signal A signal is said to be properly sampled if the original signal can be exactly reconstructed from the digital information It turns out that a signal can only be properly reconstructed if the signal does not contain frequencies above one half of the sampling rate This is
48. agreement and statement of limited warranty FIRMWARE LICENSE AGREEMENT The firmware in this instrument is protected by United States copyright law and international treaty provisions To maintain the warranty the code contained in the firmware must not be modified Any changes made to the code is at the user s risk Lake Shore will assume no responsibility for damage or errors incurred as result of any changes made to the firmware Under the terms of this agreement you may only use the Model 455 firmware as physically installed in the instrument Archival copies are strictly forbidden You may not decompile disassemble or reverse engineer the firmware If you suspect there are problems with the firmware return the instrument to Lake Shore for repair under the terms of the Limited Warranty specified above Any unauthorized duplication or use of the Model 455 firmware in whole or in part in print or in any other storage and retrieval system is forbidden TRADEMARK ACKNOWLEDGMENT Many manufacturers and sellers claim designations used to distinguish their products as trademarks Where those designations appear in this manual and Lake Shore was aware of a trademark claim they appear with initial capital letters and the or symbol LabVIEW and NI 488 2 are trademarks of National Instruments MS DOS and Windows are trademarks of Microsoft Corp PC XT AT and PS 2 are trademarks of IBM Copyright 2006 2009 and 2011 2014 b
49. apply to you 13 Except to the extent allowed by applicable law the terms of this limited warranty statement do not exclude restrict or modify the mandatory statutory rights applicable to the sale of the product to you Lake Shore Model 455 Gaussmeter User s Manual CERTIFICATION Lake Shore certifies that this product has been inspected and tested in accordance with its published specifications and that this product met its published specifications at the time of shipment The accuracy and calibration of this product at the time of shipment are traceable to the United States National Institute of Standards and Technology NIST formerly known as the National Bureau of Standards NBS FIRMWARE LIMITATIONS Lake Shore has worked to ensure that the Model 455 firmware is as free of errors as possible and that the results you obtain from the instrument are accurate and reliable However as with any computer based software the possibility of errors exists In any important research as when using any laboratory equipment results should be carefully examined and rechecked before final conclusions are drawn Neither Lake Shore nor anyone else involved in the creation or production of this firmware can pay for loss of time inconvenience loss of use of the product or property damage caused by this product or its failure to work or any other incidental or consequential damages Use of our product implies that you understand the Lake Shore license
50. by the Hall device is read by the A D at 50 kHz and is then digitally processed using a product detector and a low pass filter to create a broadband AC reading The readings are then passed through an RMS conversion routine Refer to Section 4 7 2 for information on how to set the AC measurement band Analog Output 2 can be used to output a digitally derived AC representation of the field being measured Frequency Analog Reference Output 2 from __ Read A D ee g Lowpass to A D 50 kHz Filter Filter uP Multiplier 455_Block_3 bmp Figure 2 3 RMS Narrow Band AC Block Diagram In wide band AC measurement the instrument uses a 100 mA DC excitation current This type of excitation provides the greatest frequency range for RMS measurements up to 20 kHz The voltage that is generated by the Hall device is read by the A D at 40 kHz The readings are then passed through a RMS conversion routine Refer to Section 4 7 2 for information on how to set the AC measurement band Analog Output can be used to output a real time AC representation of the field being measured Analog Output 2 can also be used to output a digitally derived AC representation of the field for measured fields up to 10 kHz Measured fields up to 20 kHz may be represented with the addition of external filters to the analog output Analog Output 2 Lowpass from Read A D Lowpass AID 40 kHz ue Antialiasing i Filter j Figure 2 4
51. conductor connector cable as specified by the standard Refer to Section 8 11 2 Cables can be purchased from Lake Shore or other electronic suppliers A connector extender Model 4005 is required to use the IEEE 488 Interface and the Auxiliary connector at the same time Cable lengths are limited to 2 meters for each device and 20 meters for the entire bus The Model 455 can drive a bus with up to 10 loads If more instruments or cable length is required a bus expander must be used Remote Operation 6 1 Lake Shore Model 455 Gaussmeter User s Manual 6 1 1 Changing IEEE 488 Interface Parameters Two interface parameters address and terminators must be set from the front panel before communication with the instrument can be established Other interface parameters can be set via the interface using the device specific commands provided in Section 6 3 To set the IEEE 488 parameters press the Interface key and press Enter to skip past Serial Interface Baud Rate The following computer interface screen appears as a prompt for the IEEE 488 address Use the A or V key to select an address between 1 and 30 The default is twelve Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display The next interface screen appears as a prompt for the IEEE 488 terminators Use the A or V key to select one of the following termina
52. continue from the Max Hold mode screen or press and hold Max Hold and then press Enter until the following screen appears as a prompt for Max Hold display setup Use the A or V key to select Max Min or Both Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 4 7 6 RMS Operation Reset If the Max Hold function is on and the Reset key is pressed the maximum and minimum readings are cleared and reset with the present field reading 4 7 7 RMS Operation Relative The relative function lets the user see small variations in larger fields When the relative function is on the relative readings will appear on the top line of the display including the small delta sign A signifying the relative display The displayed reading is equal to the present field value minus the relative setpoint The relative setpoint can be configured to be the present field reading or it can be a user defined value The relative setpoint can be displayed on the bottom display Refer to Section 4 4 1 To configure the relative setpoint press and hold the Relative key for approximately 4 seconds The relative setup screen appears as a prompt for selecting the source of the relative setpoint Use the A or V key to select Present Field or User Defined Press Enter to accept the new selection and return to the normal display Press Escape to cancel the
53. convert it to SI e g 1 G x 10 T G 10 T c SI Syst me International d Unit s has been adopted by the National Bureau of Standards Where two conversion factors are given the upper one is recognized under or consistent with SI and is based on the definition B ua M where to uo 47 x 10 Him The lower one is not recognized under SI and is based on the definition B uoH J where the symbol I is often used in place of J d 1 gauss 10 gamma y e Both oersted and gauss are expressed as cm g s in terms of base units f A m was often expressed as ampere turn per meter when used for magnetic field strength g Magnetic moment per unit volume h The designation emu is not a unit i Recognized under SI even though based on the definition B uoH J See footnote c j Hz uns 1 all in SI u is equal to Gaussian y k B Hand uch H have SI units Jim M Hand B H 4r have Gaussian units erg cm R B Goldfarb and F R Fickett U S Department of Commerce National Bureau of Standards Bolder Colorado 80303 March 1985 NBS Special Publication 696 For sale by the Superintendent of Documents U S Government Printing Office Washington D C 20402 Service Lake Shore Model 455 Gaussmeter User s Manual Table A 2 Recommended SI Values for Physical Constants Femi Vaan ae 0 0073 Fine Structure Constant u0ce2 2h a a 137 0360 Elementary Charge Pee eee ie 1 6022x10 C x 10 C Plank s C
54. converter This voltage is corrected for the nominal sensitivity of the probe and adjusted for the zero offset The output is updated at a rate of 40 000 readings per second Operation DC Operation 4 11 Lake Shore Model 455 Gaussmeter User s Manual 4 7 RMS MEASUREMENT MODE To measure periodic AC fields press the RMS key on the front panel In RMS measurement mode the keypad and functionality of the Model 455 is optimized to provide the best interaction for RMS measurements The keypad features are described in paragraphs 4 7 1 through 4 7 8 The instrument communicates the present RMS measurement band when entering RMS mode When the RMS key is pressed the following message will appear for approximately 3 seconds Note This display screen is an example of having the AC wide band mode selected refer to Section 4 7 2 for measurement band configuration 4 7 1 RMS Operation Select Range and Autorange The Model 455 reads each Lake Shore probe type High Stability High Sensitivity and Ultra High Sensitivity The tables below list full scale ranges for each probe sensitivity along with the display resolution Measurement resolution noise floor varies depending on probe and application but the Model 455 can typically measure signals as small as 0 1 of full scale range High Stability Probe HST G
55. display Table 4 1 Default Parameter Values Alarm and Relay Filter Alarni er heen a EA Off DE Resolution i oisein n 5 Alarm Mode Magnitude RMS Measurement Band Wide Alarm Trigger esceeeeeeeseeceseeeneeees Outside Keypad Locking Alarm Audible iesnisseiinsnissessss On Modes ee E dveettvce Unlocked Relay Dierenees Manual Off Lock Coden riean e s 123 Relay Se e EE ee Manual Off Measurement Analog Output Measurement Mode s sseneneneseoeoo0resoerene DC Analog Output 3 Mode Off AUtOran ge ve ENEE On Analog Output 3 Polarity 4 Bipolar Field Compensapon e On Analog Output 3 Limit ee 10V Temperature Compensation s ssssssses000 0 On Analog Output 3 Manual Out 0 Peak Mode egener nannies Pulse Computer Interface Peak Dieplan Both Baud BE 9600 Max Holdt nno Off TEEE Addies Siiran aa 12 Max Mode viecsictiscsecsnecssethisiboetesetse Magnitude IEEE Terminators CR LF Max Displayen en Both Display Relat esar whine ewe a Off Bottom Line perereca Temp Freq Remote Local Brghtmeeg 22220 715 Remote Local 0 0 eee ceeeeeeeeeeeeeees Local Field Units pnn ateei Gauss Temperature Uute C Indicates value is also initialized on power up Operation 4 27 Lake Shore Model 455 Gaussmeter User s Manual This Page Intentionally Left Blank 4 28 Operation Lake Shore Model 455 Gaussmeter User s Manual CHAPTER 5 ADVANCED OPERATION 5 0 GENERAL This chapter provides inform
56. following example shows two different ways of sending the same command Refer to the individual command descriptions for further details RELSP 2 0E 03 term Command will set the Relative setpoint value to 2000 RELSP 2000 term Command will set the Relative setpoint value to 2000 6 24 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual Table 6 9 Command Summary Command CLS KESE KESE ESR IDN OPC OPC KRST SRE SRE STB TST KWAI ALARM ALARM ALARMST ANALOG ANALOG AOUT AUTO AUTO BAUD BAUD BEEP BEEP BRIGT BRIGT DFLT DISPLAY DISPLAY IEEE IEEE KEYST LOCK LOCK MXHOLD MXHOLD MXRST Function Page Clear Interface Cmd oisi o a nE 6 26 Standard Event Status Enable Register Cmd 6 26 Standard Event Status Enable Register Query 6 26 Standard Event Status Register Query 0 6 26 Identification Ouerg cc ceeeeeeeeeeeteeteeneeneeeneeee 6 26 Operation Complete Cmd 6 26 Operation Complete Ouer 6 27 Reset Instrument Cmd ou eects 6 27 Service Request Enable Register Cmd 6 27 Service Request Enable Register Query 6 27 Status Byte Ouer 6 27 Self Test Query cccesceseeseeecceeceeeeeeteeeeeneeeeeeees 6 27 Wait To Continue Cid eee eee 6 27 Alarm Parameter Cm cece eeeeeeeeeeee 6 28 Alarm Parameter Ouer 6 28 Alarm Status Query ccccscseceeseeseeseeseeseeneeneeeneeee 6 28 Analog Output 3 Parameter Cm
57. in probe selection Application dictates the physical manifestation of the measured field including the parameters described briefly below along with relevant probe characteristics Magnitude Typical Hall probes cover an operating range of four to five orders of field magnitude Operation beyond this range often requires some compromise in performance which is often higher noise or loss of resolution Choosing the correct probe type ensures optimal performance in the desired measurement range High Sensitivity HSE High sensitivity probes are the most common for general purpose field measurement They operate effectively in fields up to 35 kG 3 5 T with excellent sensitivity over their entire range At low fields their sensitivity can be as low as 5 mG 0 5 uT HSE probes have a relatively small active area making them convenient for many applications and they are offered in a variety of stem geometries for convenience High Stability HST With a high field range of up to 350 kG 35 T high stability probes are used when fields exceed the 35 kG 3 5 T limit of HSE probes Their low field performance is slightly degraded with minimum sensitivity of 50 mG 5 uT High stability probes are also inherently more temperature stable than other probes and should be used when large temperature excursions are expected The same probe geometries are available for both HST and HSE probes HST probes are not to be used at frequencies above 800 Hz Ult
58. mmddyyyy lt manufacture gt Manufacturer ID lt model gt Instrument model number lt serial gt Serial number lt date gt Instrument firmware revision date Example LSCI MODEL455 1234567 06122003 OPC Operation Complete Command Input xOPC term Remarks Used in conjunction with bit 0 OPC of the Standard Event Status Register If sent as the last command in a command sequence bit 0 will be set when the instrument completes the operation that was initiated by the command sequence Refer to Section 6 1 4 3 6 for more information 6 26 Remote Operation OPC Input Returned Remarks RST Input Remarks SRE Input Format Remarks SRE Input Returned Format STB Input Returned Format Remarks TST Input Returned Format Remarks WAI Input Remarks Lake Shore Model 455 Gaussmeter User s Manual Operation Complete Query OPC term 1 term Has no interaction with bit 0 OPC of the Standard Event Status Register If sent at the end of a command sequence the bus will be held until the instrument completes the operation that was initiated by the command sequence Once the sequence is complete a 1 will be placed in the output buffer Refer to Section 6 1 4 3 6 for more information Reset Instrument Command RST term Sets controller parameters to power up settings Use the DELT command to set factory defaults Service Request Enable Register Command
59. new selection and return to the normal display 4 14 RMS Operation Operation Lake Shore Model 455 Gaussmeter User s Manual RMS Operation Relative Continued To turn the relative function on press the Relative key The following screen will appear for approximately 3 seconds and the Relative LED will light The relative function also interacts with other features Relative can be used with Max Hold to display the maximum relative reading To turn the Relative function off press the Relative key If the relative mode is configured to use the present field as the setpoint the Off to On transition will capture the field reading to use as the setpoint If a User Defined setpoint is selected the following screen appears as a prompt for entering the setpoint after the Relative On display disappears Use the data entry keys to enter the relative setpoint between 350 kG or equivalent depending on selected field units Enter the numeric value first Press Enter to accept the new value and advance to the units multiplier Use the A or V key to select a units multiplier of u m blank k or M depending on selected field units Press Enter to accept the new selection and return to the normal display Press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display 4 7 8 RMS Operation Analog Output 1 and 2 If the instrument is con
60. of merchantability and fitness for a particular purpose Specifically except as provided herein Lake Shore undertakes no responsibility that the products will be fit for any particular purpose for which you may be buying the Products Any implied warranty is limited in duration to the warranty period No oral or written information or advice given by the Company its Agents or Employees shall create a warranty or in any way increase the scope of this limited warranty Some countries states or provinces do not allow limitations on an implied warranty so the above limitation or exclusion might not apply to you This warranty gives you specific legal rights and you might also have other rights that vary from country to country state to state or province to province 8 Further with regard to the United Nations Convention for International Sale of Goods CISC if CISG is found to apply in relation to this agreement which is specifically disclaimed by Lake Shore then this limited warranty excludes warranties that a the Product is fit for the purpose for which goods of the same description would ordinarily be used b the Product is fit for any particular purpose expressly or impliedly made known to Lake Shore at the time of the conclusion of the contract c the Product is contained or packaged in a manner usual for such goods or in a manner adequate to preserve and protect such goods where it is shipped by someone other than a carrier hired by Lake
61. or Algebraic measurements Alarm Alarm Alarm Gamm Alarm On Off On Of On kG kG 1kG kG 1kG 2 kG 3kG Eanpb ca o0ptalon Low EN Alam Wiggered by reading Point OUT BIDE wer dedred se pine In Magnitude Wade High oan Point Alarm_Outside_M eps 4 20 Operation Lake Shore Model 455 Gaussmeter User s Manual Gamm Alarm Ala m Alarm Alarm Off On Ott On Of 3 kG 7 kG 1 kG Dk Al kG Ak 3 kG a A Bampe ofopersion Low Alanm ml Aam Wiggered by readings INBID Guster dened pone Point in Magn Hude Mode High dam Point Alarm_Inside_M eps Alarm Alarm Alarm On OUT On 3kG 2 kG Akt OkG 1kG 2 kG 3kG Bample dopersion Alam hered by readings Low Alarm High Alarm OUT BIDE Wer dedned se pone In dg abraio Mede Point Point Alarm_Outside_A eps Alam Alarm Alarm Off On Um m l 3 kG kG 1kG Ok 1 kG 2 kG 43 kG Eampie of qgeralon 4 Dam Wiggeredby reading IN BDE wer dedred ponk Low Gamm High Alarm In g ebralo Mode Point Point Alarm_Inside_A eps The Model 455 has an audible alarm annunciator or beeper The beeper will sound when the instrument is in an active alarm state If the sound of the beeper is not appropriate for your application it can be turned on or off by the user To configure the beeper continue from the alarm inside outside setup screen or press and hold Alarm and then press Enter until the following screen appears as a prompt for configuring the beeper
62. output Test this factor to be 1 0 1 Record this value Send the Gain Correction Factor GCF to the Model 455 CALG 4 3 lt GCF gt Configure Analog Output 3 to manual mode 0 ANALOG 3 2 0 0 0 10 Read the voltage using the DVM Record as VZERO Calculate the Offset Correction Factor OCF VZERO 100 10 Note The offset voltage is expressed as a percentage of Full Scale Test this factor to be between 1 and 1 Record this value Send the Offset Correction Factor OCF to the Model 455 CALZ 4 3 lt OCF gt Configure Analog Output 3 to manual mode 100 ANALOG 3 2 0 0 100 10 Read the voltage using the DVM Verify the reading to be 10 VDC 1 mV Record the reading Configure Analog Output 3 to manual mode 100 ANALOG 3 2 0 0 100 10 Read the voltage using the DVM Verify the reading to be 10 VDC 1 mV Record the reading Configure Analog Output 3 to manual mode 0 ANALOG 3 2 0 0 0 10 Read the voltage using the DVM Verify the reading to be 0 VDC 1 mV Record the reading Send the CALSAVE command to save the calibration constants into non volatile memory Service 8 15 Lake Shore Model 455 Gaussmeter User s Manual 8 11 5 Calibration Specific Interface Commands CALG Gain Calibration Constant Command Input CALG lt type gt lt range gt lt value gt term Format n n tnnnnnnn lt type gt Specifies the item to calibrate Valid entries are 1 100 mA hall current source
63. probe tip and active area is specified for axial probes but is less easily defined for transverse probes Nominal Active Area HSE and HST probes have a nominal active area on the order of 1mm diameter which is useful for all but the most stringent applications The measured field is the average over the active area but without severe gradients the measured value accurately represents the true field Field mapping with standard probes is also practical if a mapping resolution of 1mm or greater is acceptable Small Active Area HSE and HST probes with a smaller active area are also available from Lake Shore for measurements in severe gradients They should also be chosen for high resolution mapping applications UHS Probes UHS probes have a very large active length up to 3 5 in 8 9 cm They are designed to measure large ambient fields with little gradient Probe Durability All Hall effect probes are fragile The sensor normally located at the tip of the probe stem must not be bent physically shocked or abraded Many users purchase probes with the thinnest transverse stem or smallest diameter axial stem thinking that these probes should fit all future applications However this may be a big mistake Always use the most robust probe that fits the immediate application For instance the HMMT 6J04 VH aluminum stem is less prone to damage than the HMFT 3E03 VH flexible stem The HMMA 2502 VH 1 4 inch diameter aluminum is more robust
64. procedure is given in Section 8 2 Probes are shipped in cardboard containers and are often included in the instrument shipping carton Please retain the probe container for probe storage This will help protect the delicate probes from being damaged Items Included with the Model 455 Gaussmeter 1 Model 455 Instrument Model 455 User s Manual T O Mating Connector Zero Gauss Chamber Line Power Cord Line Power Cord for Alternative Voltage Se Se Se eS eS bech Fuse Pair for Alternative Voltage Included only when purchased with VAC 120 ALL Power Option Installation 3 1 Lake Shore Model 455 Gaussmeter User s Manual 3 2 REAR PANEL DEFINITION This paragraph defines the rear panel of the Model 455 See Figure 3 1 Readers are referred to paragraphs that contain installation instructions and connector pin outs for each feature A summary of connector pin outs is provided in Section 8 10 CAUTION Verify that the AC line voltage indicator in the fuse drawer window shows the appropriate AC line voltage before turning the instrument on CAUTION Make rear panel connections with the instrument power off Includes the IEC 320 C14 line cord receptacle instrument power switch and line Peme input Assembly voltage selector with line voltage indicator and line fuse holder Refer to Section 3 3 9 pin D sub plug wired in DTE configuration for use with RS 232C serial computer Oh SERIE LONE interface Refer to
65. referred to as the Nyquist frequency In the case of the Model 455 the ADC is sampled at 40 kHz in wide band AC mode In this mode the highest frequency signal that can be accurately represented out of Analog Output 2 is 20 kHz due to the limit of the Nyquist frequency In this case Analog Output 1 should be used to monitor the signal Background 2 1 Lake Shore Model 455 Gaussmeter User s Manual Limitations of Sampled Data Systems Continued It should be noted that although the Nyquist frequency will limit the signal that can be accurately reconstructed it doesn t affect the RMS reading of the signal The energy content of the signal above the Nyquist frequency will be aliased to lower frequencies where it will be included in the RMS calculation 2 1 4 Model 455 System Overview The Model 455 Gaussmeter is a highly configurable device with many built in features To better illustrate the capabilities of the DSP Gaussmeter refer to the Model 455 system block diagram Figure 2 1 The Model 455 uses a 100 mA 5 kHz square wave excitation to drive the Hall sensor in DC mode and narrow band AC mode In wide band AC mode it uses a 100 mA DC excitation to drive the sensor The Hall voltage produced by the sensor is fed back into the instrument and sent through a programmable gain stage The signal is then AC coupled into the A D where it is read at up to 50 kHz Those signals are then sent to the DSP where the signal processing is done an
66. s Manual In addition the installer of the Model 455 should consider the following e Shield measurement and computer interface cables e Leave no unused or unterminated cables attached to the instrument e Make cable runs as short and direct as possible Higher radiated emissions is possible with long cables e Do not tightly bundle cables that carry different types of signals Lake Shore Model 455 Gaussmeter User s Manual TABLE OF CONTENTS Chapter Section Title Page 1 INTRODUG TION DEE 1 1 1 0 GENERAL s c005 cies i ede a nett Ce eset 1 1 1 1 DESCRIPTION iiini eiai an ethan vase ind i Eege Za 1 1 1 1 1 Measurement Features 1 2 1 1 2 Instrument Probe Features 1 2 1 1 3 Display and Interface Features 1 3 1 2 SPECIFICATIONS egene Nolin vee iene Ada ale ee ee 1 4 1 3 SAFETY SUMMARY geed dd Get dated 1 8 1 4 SAFETY SYMBOLS riskidan iati i eile eta eee 1 8 2 BACK GROUND eege enaena dat aerar aaa eE O AE aea EES ES e 2 1 2 0 SEN Ee Ee eeh eeh ees 2 1 2 1 MODEL 455 THEORY OF OPERATION sssssssssrssrssrssirssrssrssrissrissrisstissrnssrnssrnnsrnenrnntt 2 1 2 1 1 Sampled Data Gvetems A 2 1 2 1 2 Digital Signal Processing c ccceecceeeeeeeeeeeeeeeeeceaeeeeaaeeeeneeseeeeseaeeeeaaeseeeeeseaeeesaeeeeneeeeeeeee 2 1 2 1 3 Limitations of Sampled Data Gvstems te 2 1 2 1 4 Model 455 System OvervieW ccccccceeseeceeeeeceeeeecaeeeeaeeseeeeeceaeeeeaaeeseaeeseaeeeseaeestaeeseneeseaees 2 2 2 1 5 Ren EE 2 2 2 1 6 RMS Measureme
67. second The Analog Output 2 is equipped with a two pole analog lowpass filter at 145 kHz The individual D A samples are still visible and the signal may be improved with the addition of external analog filters 4 18 Peak Operation Operation Lake Shore Model 455 Gaussmeter User s Manual 4 9 TEMPERATURE MEASUREMENT The Model 455 is capable of measuring the temperature of the probe if the probe is equipped with a temperature sensor and a temperature compensation table The probe temperature can be displayed as Kelvin or in degrees Celsius Refer to Section 4 4 1 for display setup 4 10 ALARM The alarm gives an audible and visual indication when the field value is outside or inside a user specified range When the alarm feature is turned on the LED annunciator will be on If any alarm is active the LED will blink at a steady rate An audible alarm beeper can be programmed to sound if any alarm is active Two relays can also be programmed to follow alarm operation see Section 4 11 Press the Alarm key to begin alarm setup The following alarm setup screen appears as a prompt for turning the alarm feature on or off Use the A or W key to select Off or On Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display The next alarm setup screen appears as a prompt for the low alarm setpoint value Use the data en
68. than the HMNA 1904 VH 3 16 inch diameter fiberglass with its exposed Hall sensor One last comment about probe handling never fasten a probe stem to another object If a probe is to be clamped always clamp to the handle Probes and Accessories 7 3 Lake Shore Model 455 Gaussmeter User s Manual 7 3 2 Radiation Effects on Gaussmeter Probes The HST and HSE probes use a highly doped indium arsenide active material The HST material is the more highly doped of the two and therefore will be less affected by radiation Some general information relating to highly doped indium arsenide Hall generators is as follows e Gamma radiation seems to have little effect on the Hall generators e Proton radiation up to 10 Mrad causes sensitivity changes lt 0 5 e Neutron cumulative radiation gt 0 1 MeV 10 sq cm can cause a 3 to 5 decrease in sensitivity In all cases the radiation effects seem to saturate and diminish with length of time exposed 7 3 3 Probe Accuracy Considerations The user must consider all the possible contributors to the accuracy of the reading Both the probe and gaussmeter have accuracy specifications that may impact the actual reading The probe should be zeroed before making critical measurements The zero probe function is used to null cancel out the zero offset of the probe or small magnetic fields It is normally used in conjunction with the zero gauss chamber but may also be used with an open probe registeri
69. the Product 5 This limited warranty does not apply to defects in the Product resulting from a improper or inadequate installation unless OT amp V services are performed by Lake Shore maintenance repair or calibration b fuses software power surges lightning and non rechargeable batteries c software interfacing parts or other supplies not furnished by Lake Shore d unauthorized modification or misuse e operation outside of the published specifications f improper site preparation or site maintenance g natural disasters such as flood fire wind or earthquake or h damage during shipment other than original shipment to you if shipped through a Lake Shore carrier 6 This limited warranty does not cover a regularly scheduled or ordinary and expected recalibrations of the Product b accessories to the Product such as probe tips and cables holders wire grease varnish feed throughs etc c consumables used in conjunction with the Product such as probe tips and cables probe holders sample tails rods and holders ceramic putty for mounting samples Hall sample cards Hall sample enclosures etc or d non Lake Shore branded Products that are integrated with the Product 7 To the extent allowed by applicable law this limited warranty is the only warranty applicable to the Product and replaces all other warranties or conditions express or implied including but not limited to the implied warranties or conditions
70. the response ENTER COMMAND IDN Identification query Instrument will return a string identifying itself RESPONSE LSCI MODEL455 1234567 02032003 term ENTER COMMAND RDGFIELD Field reading query Instrument will return a string with the present field reading in the present units RESPONSE 273 150E 00 term ENTER COMMAND RANGE 1 Field range command Instrument will set to the lowest range No response will be sent ENTER COMMAND RANGE Field range query Instrument will return a string with the present field range setting RESPONSE 1 term ENTER COMMAND RANGE 5 RANGE Field range command followed by a query Instrument will change to the highest range setting then return a string RESPONSE 5 term with the present setting The following are additional notes on using either IEEE 488 Interface program s Ifyou enter a correctly spelled query without a nothing will be returned Incorrectly spelled commands and queries are ignored Commands and queries should have a space separating the command and associated parameters e Leading zeros and zeros following a decimal point are not needed in a command string but are sent in response to a query A leading is not required but a leading is required 6 1 6 Troubleshooting New Installation Check instrument address Always send terminators Send entire messag
71. three years from the date of Purchaser s physical receipt of the Product the Warranty Period If Lake Shore receives notice of any such defects during the Warranty Period and the defective Product is shipped freight prepaid back to Lake Shore Lake Shore will at its option either repair or replace the Product if it is so defective without charge for parts service labor or associated customary return shipping cost to the Purchaser Replacement for the Product may be by either new or equivalent in performance to new Replacement or repaired parts or a replaced Product will be warranted for only the unexpired portion of the original warranty or 90 days whichever is greater 2 Lake Shore warrants the Product only if the Product has been sold by an authorized Lake Shore employee sales representative dealer or an authorized Lake Shore original equipment manufacturer OEM 3 The Product may contain remanufactured parts equivalent to new in performance or may have been subject to incidental use when it is originally sold to the Purchaser 4 The Warranty Period begins on the date of Purchaser s physical receipt of the Product or later on the date of operational training and verification OT amp V of the Product if the service is performed by Lake Shore provided that if the Purchaser schedules or delays the Lake Shore OT amp V_ for more than 30 days after delivery then the Warranty Period begins on the 31st day after Purchaser s physical receipt of
72. up for at least 5 minutes before zeroing the probe and at least 30 minutes for rated accuracy The probe and the zero gauss chamber should be at the same temperature If the exact direction of the magnetic field is unknown the proper magnitude is determined by turning on Max Hold and slowly adjusting the probe As the probe turns and the measured field rises and falls its maximum value is held on the display Make note of the probe orientation at the maximum reading to identify the field orientation Lake Shore logo towards north pole ni o m Li Transverse probe orientation for positive measurement B ae Axial probe orientation for positive measurement Figure 3 4 Probe Orientation For Positive Measurement Installation 3 5 Lake Shore Model 455 Gaussmeter User s Manual 3 5 3 Probe Accuracy Considerations The user must consider all the possible contributors to the accuracy of the reading Both the probe and gaussmeter have accuracy specifications that may impact the actual reading The probe should be zeroed before making critical measurements The zero probe function is used to null cancel out the zero offset of the probe or small magnetic fields It is normally used in conjunction with the zero gauss chamber but may also be used with an open probe registering the local earth magnetic field Users wishing to cancel out large magnetic fields should use the Relative function Refer to Section 4 6 6 Pro
73. will be zero volts Default 3 5 volts will equal full scale for the selected range User Def 10 volts will equal user defined field values Manual The output of Analog 3 can be manually set as a percent in the range 100 To configure the Analog Output 3 mode press the Analog Output key The analog setup screen appears as a prompt for selecting the mode of operation Use the A or F key to select from Off Default User Defined or Manual Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display If the instrument is configured for Default the following image represents the displayed field versus voltage output for the 3 5 kG range Scale changes with range 0kG GL App 25kG 15kG 1 5kKG 25kG 43 5kG Output 3 5 V 25V 1 5 V 1 5 V 2 5 V 3 5 V Voltage 7 gt Eu ER OV sia i If the User Defined mode is selected the next analog setup screen appears as a prompt for the low setpoint value This value represents the reading at which the Analog Output 3 will be 10 volts Use the data entry keys to enter the low setpoint between 350 kG or equivalent depending on selected field units Enter the numeric value first Press Enter to accept the new value and advance to the units multiplier Use the A or V key to select a units multiplier of u m blank k or M depending on selected field units Press Enter to acc
74. 1 1 Model 455 Front Panel Introduction 1 1 Lake Shore Model 455 Gaussmeter User s Manual Description Continued RMS Measurement Mode Periodic AC fields are measured in RMS mode The Model 455 provides an overall RMS frequency range of 10 Hz to 20 kHz and is equipped with both narrow and wide band frequency modes While in narrow band mode frequencies above 1 kHz are filtered out for improved measurement performance The exclusive DSP algorithms free the Model 455 from the limitations of conventional RMS conversion hardware and provide for an excellent dynamic range resolution and frequency response Peak Measurement Mode Pulsed fields are measured in Peak mode which is a natural extension of the high speed data acquisition necessary for DSP operation Fast instrument sample rates permit capture of positive and negative transient fields as narrow as 50 us pulse widths The peak reading can be held for an unlimited length of time with no sag This is ideal for most magnetizers and other fast pulse applications The Model 455 can also be configured to follow the peak of a periodic waveform for evaluation of crest factor The Probe Connection The Model 455 is only half of the magnetic measurement equation For the complete solution Lake Shore offers a full complement of standard and custom Hall effect probes in a variety of sizes and sensitivities One of ten common standard Hall probes is included with the Model 455 Refer to Section 7
75. 10 Ground Wire Twisted pair with SRQ 23 GND 11 Ground Wire Twisted pair with ATN 24 GND Logic Ground Figure 8 7 IEEE 488 INTERFACE Connector Details 8 10 Service Lake Shore Model 455 Gaussmeter User s Manual 8 11 CALIBRATION PROCEDURE 8 11 1 Equipment Required for Calibration PC and Interface e PC with software loaded which provides serial command line communication Example program in Section 6 2 7 is ideal for this purpose e DE 9 to DE 9 cable Pin to pin connections on all 9 pins Female connectors on both ends e DE 9 null modem adapter Test and Measurement Equipment e Digital Voltmeter DVM Voltage and current specs to be equivalent to or better than HP3458 specs e Function Generator Frequency and voltage specs to be equivalent to or better than HP Agilent 33120 specs e One 332 Q 0 1 25 ppm resistor e One 33 2 Q 0 1 25 ppm resistor e One 3 Q 0 02 4 lead resistor Precision Resistor Corporation PLV 3 or equivalent e One 300 mQ 0 02 4 lead resistor Precision Resistor Corporation PLV or equivalent e One 30 mQ 0 05 4 lead resistor Precision Resistor Corporation PL NG or equivalent e One 4 3 mQ 0 25 4 lead resistor created by placing a 30 mQ and a 5 mQ resistor in parallel Precision Resistor Corporation PLV or equivalent e One 2 KQ 0 1 25 ppm resistor e One 22 1 KQ 0 1 25 ppm resistor e One 200 KQ 0 1 25 ppm resistor 8 11 2 Gaussmeter Calibrat
76. 2 10 mA hall current source 3 1 mA hall current source 4 Analog Outputs 1 3 5 Temperature lt range gt Specifies the range of the item to calibrate Valid entries are 1 300 uQ range hall current source 10 pA range temperature Analog Output 1 not used 2 3 MQ range hall current source 100 uA range temperature Analog Output 2 3 30 MQ range hall current source 1 mA range temperature Analog Output 3 4 300 MQ range hall current source 5 3 Q range hall current source lt value gt Gain calibration constant value Remarks Some entries are not calibrated and are indicated by not used No value should be sent to these locations CALG Gain Calibration Constant Query Input CALG lt type gt lt range gt term Format n n lt type gt 1 5 lt range gt 1 5 Returned lt value gt term Format nnnnnnn Refer to command for description CALSAVE Calibration Save Command Input CALSAVE term Remarks Saves all CALZ and CALG calibration constants in non volatile memory CALTEMP Temperature Measurement Setup Command Input CALTEMP lt mode gt lt range gt term Format n n lt mode gt Specifies the operating mode of the temperature measurement Valid entries are 0 Normal mode autorange on 1 Manual range mode lt range gt Specifies the current source range of the temperature measurement Valid entries are 1 10 pA range 250 kQ range 2 100 uA range 25 KQ range 3 1 mA range 2 5 kQ ran
77. 2 1 Decimal ESR pon e ove pe 0e re fe ore Name ESR reads and clears the register To Event Summary Standard evet 7 6 5 4 3 2 1 0 sit S E ae Status Enable 138 64 32 16 8 4 2 1 pecima SU Register Register Not Not Not a Figure_6 2 bmp Figure 6 2 Standard Event Status Register 6 1 4 2 2 Operation Event Register Set The Operation Event Register reports the following interface related instrument events ramp done datalog done alarm new reading field overload no probe Any or all of these events may be reported in the operation event summary bit through the enable register see Figure 6 3 The Operation Event Enable command OPSTE programs the enable register and the query command OPSTE reads it OPSTR reads and clears the Operation Event Register OPST reads the Operation Condition register The used bits of the Operation Event Register are described as follows Calibration Error CAL Bit 6 This bit is set if the instrument is not calibrated or the calibration data has been corrupted Alarm Bit 3 This bit is set when there is an alarm condition New Field Reading Bit 2 This bit is set when there is a new field reading Field Overload Bit 1 This bit is set when the field reading is in an overload condition No Probe Bit 0 This bit is set if the instrument is unable to detect a probe Remote Operation 6 7 Lake Shore Model 455 Gaussmeter Use
78. 2 Operational Status Register Ouer 6 32 Peak Hold Reset Cmd eeeeeeeeeeeseeeee 6 32 Probe Field Compensation Cmd Probe Field Compensation Query Probe Sensitivity Query 6 33 Probe Serial Number Query uu cece 6 33 Probe Temperature Compensation Cmd 6 33 Probe Temperature Compensation Query 6 33 Field Range Cmd inedi sd aas 6 33 Field Range Query s sssesessrsrerersrsrsrersrersse 6 33 Field Reading Query sesisiiensninsinenrar 6 33 Measurement Mode Cd 6 34 Measurement Mode Query cece 6 34 Frequency Reading Ouerg eects 6 34 Minimum and Maximum Reading Query 6 34 Resistance Reading Query eseseeeereereereeee 6 34 Peak Reading Ouer 6 34 Relative Reading Query c cece eeeeeseeeee 6 35 Probe Temperature Reading Query 6 35 Relative Mode Cmd o cece eeeeeseeeseeeeeee 6 35 Relative Mode Query cceccceeeeeeseeeseeeeees 6 35 Relay Parameter Cmd o0 ee eee eeeeseeeee 6 35 Relay Parameter Query cceeeeeesseeseeeeeee 6 35 Relay Status Ouer 6 36 Relative Setpoint Cmd ue eee 6 36 Relative Setpoint Query cece ee eeeeseeeeee 6 36 Probe Temperature Units Cd 6 36 Probe Temperature Units Ouer 6 36 Probe Type Ouer 6 36 Field Units CMA onis rires 6 37 Field Units Query 6 37 Clear Zero Probe Cmd Zero Probe Cmd Remote Operation 6 25 Lake Shore Model 455 Gaussmeter User s Manual
79. 2 3 for a list of available probes including details on the 1 of 10 Hall probes you can choose to receive with the Model 455 1 1 1 Measurement Features The Model 455 offers a variety of features to enhance the usability and convenience of the gaussmeter Auto Range In addition to manual range selection the instrument automatically chooses an appropriate range for the measured field Auto range works in DC and AC measurement modes Auto Probe Zero Allows the user to zero all ranges for the selected measurement mode with the push of a key Display Units Field magnitude can be displayed in units of G T Oe and A m Max Min Hold The instrument stores the fully processed maximum and minimum DC or RMS field value This differs from the faster peak capture feature that operates on broadband unprocessed field reading information Relative Reading Relative feature calculates the difference between a live reading and the relative setpoint to highlight deviation from a known field point This feature can be used in DC RMS or Peak measurement mode Instrument Calibration Lake Shore recommends an annual recalibration schedule for all precision gaussmeters Recalibrations are always available from the factory but the Model 455 allows users to field calibrate the instrument if necessary Recalibration requires a computer interface and precision low resistance standards of known value 1 1 2 Instrument Probe Features The Model 455 has the best m
80. 2 5 6 and 12 inch diameter Check the Lake Shore website for any recent additions to this line These coils are accurately calibrated using field standards maintained at Lake Shore Most standards are traceable to physical standards such as a coil of carefully controlled dimensions or in some cases to proton resonance The field strengths are measured on the basis of the field generated by a current through the coil When combined with a customer supplied power supply these coils can be used as low field reference magnets to compliment our set of standard reference magnets defined in Section 7 7 To achieve maximum field the power supply must be capable of 2 A output and a constant current mode is recommended MH 2 5 MH 6 MH 12 Inside Diameter 2 5 inches 6 inches 12 inches Field Accuracy 0 5 Field Strength B0G 1A Z25G 1A Z13G 1A Field Homogeneity 0 5 within a cylindrical 0 5 within a cylindrical 0 5 within a cylindrical volume 0 75 long volume 1 6 long volume 3 2 long 0 75 diameter located 1 6 diameter located 3 2 diameter located at center of coil at center of coil at center of coil Coil Resistance Inductance z3 O 6 3 mH 10 0 36 mH 20 Q 93 mH Maximum Continuous Current 2 A DC or AC RMS Operating Temperature Range 10 to 40 C 50 to 104 F 1 25 WIDE 1 00 HIGH OPENING THRU BOTH SIDES BANANA JACKS CURRENT INPUT Helmholtz_2 bmp Figure 7 13 Model MH 2 5 H
81. 5 pin I O connector General Ambient temperature 15 to 35 C at rated accuracy 5 to 40 C with reduced accuracy Power requirement 100 120 220 240 VAC 4 6 10 50 Hz or 60 Hz 20 VA Size 216 mm W x 89 mm H x 318 mm D 8 5 in x 3 5 in x 12 5 in half rack Weight 3 kg 6 6 Ib Approval CE mark Probes and Extensions Probe compatibility Full line of standard probes and custom probes Not compatible with Model 450 421 probes Hall sensor compatibility Front panel programmable sensitivity and serial number for user supplied Hall sensor Extension cable compatibility Calibrated or uncalibrated probe extension cables with an EEPROM are available from 10 ft to 100 ft Lake Shore calibrated extension cables maintain the same accuracy as the Model 455 probe The uncalibrated version involves the operator loading the matching probe data file into the cable PROM directly from the Model 455 front panel Additional errors caused by the uncalibrated extension cables are 0 02 of field reading error and 1 C temperature reading error Ordering Information Part Number Description 455 Model 455 Gaussmeter Specify Line Power Option VAC 100 100 VAC configured includes U S power cord VAC 120 120 VAC configured includes U S power cord VAC 220 220 VAC configured includes Universal Europe power cord VAC 240 240 VAC configured includes Universal Europe power cord VAC 120 ALL 120 VAC configured includes U S and Universal Europe power cords an
82. 5 range to the 35 Q range RANGE 4 18 Read the resistor using the Model 455 RDGOHM Store as ACTUALRESISTANCE 19 Calculate the Gain Calibration Factor GCF EXPECTEDRESISTANCE ACTUALRESISTANCE Test this factor to be 1 0 42 20 Send the Gain Calibration Factor GCF to the Model 455 CALG 3 4 lt GCF gt 21 Read the resistor using the Model 455 RDGOHM Verify the reading to be EXPECTEDRESISTANCE 0 02 22 Repeat steps 14 to 21 for the 3 5 Q and 350 mQ ranges range 3 and 2 using the 3 Q and 300 mQ resistors respectively SOOO SU SON AO E Ee 23 Send the Gain Calibration Factor GCF calculated for range 2 to range 1 The hardware gains for those two ranges are equivalent 24 Configure the Model 455 to use the 100 mA excitation current HALLCS 1 25 Send the CALSAVE command to save the calibration constants into non volatile memory Service 8 13 Lake Shore Model 455 Gaussmeter User s Manual 8 11 3 Temperature Measurement Calibration This section performs the calibration on the temperature measurement The Model 455 has three excitation currents for temperature measurement Each one of these is used to measure the appropriate 0 1 resistor Calibration constants and offsets are calculated and sent to the Model 455 Set the Temperature Gain Correction Factor to 1 and the Offset Correction Factor to 0 CALG 5 3 1 CALZ 5 3 0 Connect the 2 KQ resistor to the DVM using a proper 4 lead connection Re
83. 55 RDGOHM Store as EXPECTEDRESISTANCE SOCOM Sa ON nO IS 8 12 Service Lake Shore Model 455 Gaussmeter User s Manual 17 Configure the Model 455 range to the 3 5 Q range RANGE 4 18 Read the resistor using the Model 455 RDGOHM Store as ACTUALRESISTANCE 19 Calculate the Gain Calibration Factor GCF EXPECTEDRESISTANCE ACTUALRESISTANCE Test this factor to be 1 0 42 20 Send the Gain Calibration Factor GCF to the Model 455 CALG 2 4 lt GCF gt 21 Read the resistor using the Model 455 RDGOHM Verify the reading to be EXPECTEDRESISTANCE 0 02 22 Repeat steps 14 to 21 for the 350 mQ and 35 mQ ranges range 3 and 2 using the 300 mQ and 30 mQ resistors respectively 23 Send the Gain Calibration Factor GCF calculated for range 2 to range 1 The hardware gains for those two ranges are equivalent 24 Configure the Model 455 to use the 100 mA excitation current HALLCS 1 25 Send the CALSAVE command to save the calibration constants into non volatile memory 8 11 2 3 Gaussmeter Calibration 1mA Excitation Ranges This section describes the method of calibrating the 1 mA current source that may be used for future Hall sensors The five ranges of the Model 455 will need to be calibrated for each current setting The highest range is for each current is calibrated using a 332 Q resistor that is measured using the 3458 in a four lead resistance measurement mode The remaining ranges are calibrated b
84. 6 6262 x 104 J Hz ones h ae 1 0546 x 10 J s Avogadro s Constant 6 0220 x 10 mol 91 10 k 1 6726 x 10 k 1 6749 x 107 k erie SE gespent T A Data abbreviated to 4 decimal places from CODATA Bulletin No 11 ICSU CODATA Central Office 19 Westendstrasse 6 Frankfurt Main Germany Copies of this bulletin are available from this office 8 20 Service
85. Generator Cable Assembly The HMCBL Cable Assembly connects a discrete Hall generator to the Model 455 Gaussmeter Refer to Section 7 5 Because of the many calibration intricacies the user is responsible for measurement accuracy Refer to Section 5 2 for programming instructions HMCBL 6 Hall Generator Cable Assembly 2 meters 6 feet HMCBL 20 Hall Generator Cable Assembly 6 meters 20 feet Helmholtz Coils Provides stable low magnetic field when used with customer supplied power supply Often used to provide reference field to help check gaussmeter accuracy Three coils are available as follows Refer to Section 7 6 MH 2 5 Helmholtz Coil 2 5 inch inner diameter field strength 30 G 1 A maximum continuous current 2 A coil resistance x3 Q See Figure 7 13 MH 6 Helmholtz Coil 6 inch inner diameter field strength 25 G 1 A maximum continuous current 2 A Coil Resistance 10 See Figure 7 14 MH 12 Helmholtz Coil 12 inch inner diameter field strength 13 G 1 A maximum continuous current 2 A Coil Resistance 20 See Figure 7 15 Reference Magnets High quality reference magnets are available in transverse flat and axial round configurations Refer to Section 7 7 and see Figure 7 16 MRA 312 100 MRA 312 200 MRA 312 300 MRA 312 500 MRA 312 1K MRA 312 2K MRT 062 200 MRT 062 500 MRT 062 1K MRT 062 2K MRT 062 5K MRT 343 50 MRT 343 100 MRT 062 10K Axial Reference Mag
86. HGT 3030 amp HGCT 3020 Dimensions sssssessesesreerreerrereeeeeee 7 12 Axial Hall Generator HGA 3010 HGA 3030 amp HGCA 3020 Dimenslons sssssssssserneernrerernrnrnrnrnrnennnnne 7 13 Transverse Hall Generator HGT 1010 Dimensions 7 14 Model MH 2 5 Helmholt2Z Coll ge deueereedus a aie ied eege ea eee ate 7 15 ele EA Bulle e NEE 7 16 Model MET Helmholtz Coilivic c anita insta eit elas ee ditt ae cdo ee a ede eevee 7 16 Lake Shore Reference Maonets AAA 7 17 Model 4060 Zero Gauss Chamber 7 18 Model 4065 Large Zero Gauss Chamber 7 18 Fuse Drawe li enee deen ee geesde deer E ege slau GG ee had cet a 8 2 Power TEE 8 2 Location Of Important Internal Components 8 6 Auxiliary UO Connector Details AAA 8 7 PROBE INPUT Connector Details AAA 8 8 SERIAL O DTE Connector Detalls eege age dEe aa a aa Eed EES 8 8 IEEE 488 INTERFACE Connector Details 8 10 Table of Contents Lake Shore Model 455 Gaussmeter User s Manual LIST OF TABLES Table No Title Page 4 1 Default Parameter Values n diein eer oe eaten alle tiene ie Ai it diacetate 4 27 6 1 Binary Weighting of an 8 Bit Register ceeesecceseeseeeeseeeeeeseneeseseeeseeeceneeeeeeeseeseeeeensaseeesseeseeesseeeeensieeetegs 6 6 6 2 Register Glear Methods ug eegent Eesen ee EE 6 6 6 3 Programming Example to Generate an GO 6 10 6 4 IEEE 488 Interface Program Control Properties 6 14 6 5 Visual Basic IEEE 488 Interface Program 6 15 6 6 Serial Interface S
87. IEW drivers are provided to instrument users Consult with Lake Shore for availability 1 2 SPECIFICATIONS Does not include probe error unless otherwise specified General Measurement Input type Single Hall effect sensor Probe features Linearity compensation temperature compensation auto probe zero and hot swap Measurement features Autorange max min hold relative mode and frequency Connector 15 pin D style DC Measurement Probe Type 5 4 digit 4 4 digit 334 digit Ranges resolution resolution resolution HST Probe 350 kG 000 001 kG 000 01 kG 000 1 kG 35 kG 00 0001 kG 00 001 kG 00 01 kG 3 5kG 0 00001 kG 0 0001 kG 0 001 kG 350 G 000 003 G 000 02 G 000 1 G 35 G 00 0030 G 00 015 G 00 04 G HSE Probe 35 kG 00 0001 kG 00 001 kG 00 01 kG 3 5kG 0 00001 kG 0 0001 kG 0 001 kG 350G 000 001 G 000 01 G 000 1 G 35G 00 0003 G 00 002 G 00 01 G 3 5G 0 00030 G 0 0015 G 0 004 G UHS Probe 35G 00 0001 G 00 001 G 00 01 G 3 5G 0 00001 G 0 0001 G 0 001 G 350 mG 000 003 mG 000 02 mG 000 1 mG 35 mG 00 0030 mG 00 015 mG 00 04 mG Measurement resolution RMS noise floor Indicated by value in above table for shorted input Probe effects not included Value measured as peak to peak divided by 6 6 Display resolution Indicated by number of digits in above table 5 4 digit 4 4 digit 3 4 digit resolution resolution resolution 3dB bandwidth 1 Hz 10 Hz 100 Hz Time constant ls 0 1 s 0 01 s Max reading rate 10 r
88. ILIARY I O Connector Details Service 8 7 Lake Shore Model 455 Gaussmeter User s Manual PROBE INPUT Probe_Input bmp Pin Description Pin Description 1 V input 9 V input 2 No Connection 10 No Connection 2 V temp 11 EEPROM GND 4 Itemp 12 EEPROM VCC 5 temp 13 EEPROM CLK 6 V temp 14 EEPROM DATA 7 No Connection 15 Thall 8 Thall Figure 8 5 PROBE INPUT Connector Details SERIAL I O DTE Serial_IO bmp Model 455 Gaussmeter Typical Computers SERIAL I O DTE DB 25P DTE DE 9P DTE Pin Description Pin Description Pin Description 1 No Connection 2 TD out 1 DCD in 2 Receive Data RD in 3 RD in 2 RD in 3 Transmit Data TD out 4 RTS out 3 TD out 4 Data Terminal Ready DTR out 5 CTS in 4 DTR out 5 Ground GND 6 DSR in 5 GND 6 Data Set Ready DSR in 7 GND 6 DSR in 7 Data Terminal Ready DTR out tied to 4 8 DCD in 7 RTS out 8 No Connection 20 DTR out 8 CTS in 9 No Connection 22 Ring in in 9 Ring in in Figure 8 6 SERIAL I O DTE Connector Details 8 8 Service Lake Shore Model 455 Gaussmeter User s Manual 8 10 1 Serial Interface Cable Wiring The following are suggested cable wiring diagrams for connecting the Model 455 Serial Interface to various Customer Personal Computers PCs Model 455 to PC Serial Interface PC with DE 9P
89. Interface 455_Block_1 bmp Figure 2 1 Model 455 System Block Diagram 2 1 5 DC Measurement The DC mode should be used to measure static or slowly changing fields When in DC mode the instrument uses a 100 mA 5kHz square wave excitation current The voltage that is generated by the Hall device is read by the A D at 50 kHz and is then digitally processed using a product detector and a low pass filter to create a DC reading The readings are then averaged using a configurable averaging filter that can give a high speed reading or a low speed high resolution reading Refer to Section 4 6 2 for information on how to set the DC filter Analog Output 2 can be used to output a digitally derived DC representation of the field being measured over the DC frequency band Frequency Reference Analog Output 2 Configurable from Lowpass Moving Lowpass AID Average Filter SES Multiplier Filter 455_Block_2 bmp Figure 2 2 DC Measurement Block Diagram 2 2 Background Lake Shore Model 455 Gaussmeter User s Manual 2 1 6 RMS Measurement The Model 455 offers two different modes of AC measurement narrow band and wide band In narrow band AC measurement the instrument uses a 100 mA 5 kHz square wave excitation current This type of excitation provides the benefit of noise cancellation characteristics of the product detector but limits the maximum frequency to approximately 1 kHz The voltage that is generated
90. LS command The register is read only 6 1 4 1 2 Enable Registers Each register set includes an enable register as shown in Figure 6 1 An enable register determines which bits in the corresponding event register will set the summary bit for the register set in the Status Byte The user may write to or read from an enable register Each event register bit is logically ANDed to the corresponding enable bit of the enable register When an enable register bit is set by the user and the corresponding bit is set in the event register the output summary of the register will be set which in turn sets the summary bit of the Status Byte register 6 1 4 1 3 Status Byte Register The Status Byte register typically referred to as simply the Status Byte is a non latching read only register that contains all of the summary bits from the register sets The status of the summary bits are controlled from the register sets as explained above The Status Byte also contains the Request for Service RQS Master Summary Status MSS bit This bit is used to control the Service Request hardware line on the bus and to report if any of the summary bits are set via the STB command The status of the RQS MSS bit is controlled by the summary bits and the Service Request Enable Register 6 1 4 1 4 Service Request Enable Register The Service Request Enable Register determines which summary bits in the Status Byte will set the RQS MSS bit of the Status Byte The user m
91. NTING kri nivale ee as 3 8 4 OPERATION eege See EE EE Eege 4 1 4 0 GENERAL sic a cis siete nid iets ete tee hte ene ae eee 4 1 4 1 TURNING POWER ON anere r eiieeii ia iiie i 4 1 4 2 DISPLAYS DE AINT O N ees ee E ene 4 2 Table of Contents i Chapter Section 4 2 1 4 2 2 4 3 4 3 1 4 3 2 4 4 4 4 1 4 4 2 4 5 4 6 4 6 1 4 6 2 4 6 3 4 6 4 4 6 4 1 4 6 4 2 4 6 5 4 6 6 4 6 7 4 7 4 7 1 4 7 2 4 7 3 4 7 4 4 7 5 4 7 5 1 4 7 6 4 7 7 4 7 8 4 8 4 8 1 4 8 2 4 8 3 4 8 4 4 8 5 4 8 6 4 8 7 4 9 4 10 4 11 4 12 4 12 1 4 12 2 4 12 3 4 13 4 14 Lake Shore Model 455 Gaussmeter User s Manual TABLE OF CONTENTS Continued Title Page Ae 4 2 Display and LED Annunciators AA 4 2 KEYPAD DEFINITION gereest eege AE gedu eneen en Hdl a ie tal ea eh Haida 4 3 Re le EEN 4 3 General Keypad Operation 4 4 DISPLAY SETUP esmarra Sacdvecddharvas saz a aaaeeeaa adada Sae ana dadaa taai ra and dotata edits 4 4 Two Line Display Configuration ccccceceeeeeeeeeeeeeeeeeeceeeeeceaeeeeaaeeseaeeseaeeesaeeesaeeseneeseaees 4 4 Display ziell 4 5 ONM een Heeb a aaa a a deena lo a a a a en 4 5 DC MEASUREMENT MODE 4 6 DC Operation Select Range and Autorange seesesssessssseseteitsiettntttnntnntnnntnnennnsen nenn 4 6 DC Operation Resolution and Filtering 0 ccccceceeeeeeeeeceeeeeeeeeeecaeeeeeeeseeeeeseaeeesaeeneseeseaees 4 7 DC Operation Zero Probe A 4 7 DG Operation Max Hold issccisvcayepedcecteascesccpe vt deasr
92. SRE lt bit weighting gt term nnn The Service Request Enable Register determines which summary bits of the Status Byte may set bit 6 RQS MSS of the Status Byte to generate a Service Request This command programs the enable register using a decimal value which corresponds to the binary weighted sum of all bits in the register Refer to Section 6 1 4 3 Service Request Enable Register Query SRE term lt bit weighting gt term nnn Refer to command for description Status Byte Query STB term lt bit weighting gt term nnn This command is similar to a Serial Poll except it is processed like any other instrument command It returns the same result as a Serial Poll except that the Status Byte bit 6 RQS MSS is not cleared Refer to Section 6 1 4 3 4 Self Test Query TST term lt status gt term n lt status gt 0 No errors found 1 Errors found The Model 455 reports status based on test done at power up Wait to Continue Command WAT term This command is not supported in the Model 455 Remote Operation 6 27 Lake Shore Model 455 Gaussmeter User s Manual ALARM Alarm Parameter Command Input ALARM lt off on gt lt mode gt lt low value gt lt high value gt lt out in gt term Format n n tnnn nnnE nn t nnn nnnE nn n lt off on gt Specifies alarm checking on or off 0 Off 1 On lt mode gt Specifies checking magnitude absolute value used or algebraically includes sign
93. Section 6 2 and see Figure 8 6 15 pin D sub socket for probes or Hall generator cables For best results secure the PROBE INPUT connector to the rear panel using the two thumbscrews Refer to Section 3 4 for additional probe considerations AUXILIARY I O 25 pin D sub plug that provides access to the analog outputs hardware triggers and relays Refer to Section 3 6 IEEE 488 INTERFACE IEEE 488 compliant interface connector for use with IEEE 488 parallel computer interface Refer to Section 6 1 and see Figure 8 7 WARNING NO USER SERVICEABLE RTS INSIDE REFER SERIAL I O DTE SERVICING TO TRAINED 3 ES SERVICE PERSONNEL 10 6 Voltage 50 50 Hz 40 VA MAX 100 120 V 0 54 5x20mmT 220 240V 0 25A 5x20 mmT IEEE 488 INTERFACE PROBE INPUT uD o 455_Rear bmp Figure 3 1 Model 455 Rear Panel 3 2 Installation Lake Shore Model 455 Gaussmeter User s Manual 3 3 LINE INPUT ASSEMBLY This section describes how to properly connect the Model 455 to line power Please follow these instructions carefully to ensure proper operation of the instrument and the safety of operators i Power Switch Line Cord Input O Off On Fuse Drawer Av LINE 10 6 Voltage 50 60 Hz 40 VA MAX 100 120 V 220 240 V 0 25 A x 20 mm T 455_Power bmp Figure 3 2 Line Input Assembly 3 3 1 Line Voltage The Model 455 has four different AC line voltages
94. Send False Set Flag as False strCommand frmIEEE txtCommand Text Get Command strReturn Clear response display strCommand UCase strCommand Set all characters to upper case If strCommand EXIT Then Get out on EXIT End End If Call ibwrt intDevice strCommand amp term Send command to instrument If ibsta And EERR Then Check for IEEE errors do error handling if needed Handle errors here End If If InStr strCommand lt gt 0 Then Check to see if query strReturn Space 100 Build empty return buffer Call ibrd intDevice strReturn Read back response If ibsta And EERR Then Check for IEEE errors do error handling if needed Handle errors here End If If strReturn lt gt Then Check if empty string strReturn RTrim strReturn Remove extra spaces and Terminators Do While Right strReturn 1 Chr 10 Or Right strReturn 1 Chr 13 strReturn Left strReturn Len strReturn 1 Loop Else strReturn No Response Send No Response End If frmIEEE txtResponse Text strReturn Put response in text on main form End If Loop End Sub Remote Operation 6 15 Lake Shore Model 455 Gaussmeter User s Manual 6 1 5 3 Program Operation Once the example program is running try the following commands and observe the response of the instrument Input from the user is shown in bold and terminators are added by the program The word term indicates the required terminators included with
95. Serial Poll Disable Serial polling accesses the Service Request Status Byte Register This status register contains important operational information from the unit requesting service The SPD command ends the polling sequence 6 1 3 2 Common Commands Common Commands are addressed commands which create commonality between instruments on the bus All instruments that comply with the IEEE 488 1987 standard share these commands and their format Common commands all begin with an asterisk They generally relate to bus and instrument status and identification Common query commands end with a question mark Model 455 common commands are detailed in Section 6 3 and summarized in Table 6 9 6 1 3 3 Device Specific Commands Device specific commands are addressed commands The Model 455 supports a variety of device specific commands to program instruments remotely from a digital computer and to transfer measurements to the computer Most device specific commands perform functions also performed from the front panel Model 455 device specific commands are detailed in Section 6 3 and summarized in Table 6 9 6 1 3 4 Message Strings A message string is a group of characters assembled to perform an interface function There are three types of message strings commands queries and responses The computer issues command and query strings through user programs the instrument issues responses Two or more command strings or queries can be ch
96. Serial Poll Serial Poll the bus to determine which instrument sent the interrupt and clear the RQS bit in the Status Byte ESR Read and clear the Standard Event Status Register allowing an SRQ to be generated on another command error 6 1 4 3 4 Using Status Byte Query STB The Status Byte Query STB command is similar to a Serial Poll except it is processed like any other instrument command The STB command returns the same result as a Serial Poll except that the Status Byte bit 6 RQS MSS is not cleared In this case bit 6 is considered the MSS bit Using the STB command does not clear any bits in the Status Byte Register 6 1 4 3 5 Using the Message Available MAV bit Status Byte summary bit 4 MAV indicates that data is available to read into your bus controller This message may be used to synchronize information exchange with the bus controller The bus controller can for example send a query command to the Model 455 and then wait for MAV to set If the MAV bit has been enabled to initiate an SRQ the user s program can direct the bus controller to look for the SRQ leaving the bus available for other use The MAV bit will be clear whenever the output buffer is empty 6 1 4 3 6 Using Operation Complete OPC and Operation Complete Query OPC The Operation Complete OPC and Operation Complete Query OPC are both used to indicate when pending device operations complete However the commands operate with tw
97. Shore 9 Lake Shore disclaims any warranties of technological value or of non infringement with respect to the Product and Lake Shore shall have no duty to defend indemnify or hold harmless you from and against any or all damages or costs incurred by you arising from the infringement of patents or trademarks or violation or copyrights by the Product 10 THIS WARRANTY IS NOT TRANSFERRABLE This warranty is not transferrable 11 Except to the extent prohibited by applicable law neither Lake Shore nor any of its subsidiaries affiliates or suppliers will be held liable for direct special incidental consequential or other damages including lost profit lost data or downtime costs arising out of the use inability to use or result of use of the product whether based in warranty contract tort or other legal theory regardless whether or not Lake Shore has been advised of the possibility of such damages Purchaser s use of the Product is entirely at Purchaser s risk Some countries states and provinces do not allow the exclusion of liability for incidental or consequential damages so the above limitation may not apply to you 12 This limited warranty gives you specific legal rights and you may also have other rights that vary within or between jurisdictions where the product is purchased and or used Some jurisdictions do not allow limitation in certain warranties and so the above limitations or exclusions of some warranties stated above may not
98. T Probe Temperature Units Query Input TUNIT term Returned lt units gt term Format n Refer to command for description TYPE Probe Type Query Input TYPE term Returned lt type gt term Format nn Remarks Returns the probe type 40 high sensitivity 41 high stability 42 ultra high sensitivity 50 user programmable cable high sensitivity probe 51 user programmable cable high stability probe 52 user programmable cable ultra high sensitivity probe 6 36 Remote Operation UNIT Input Format Example UNIT Input Returned Format ZCLEAR Input Remarks ZPROBE Input Remarks Lake Shore Model 455 Gaussmeter User s Manual Field Units Command UNIT lt units gt term n lt units gt 1 Gauss 2 Tesla 3 Oersted 4 Amp meter UNIT 2 term Configures the Model 455 to report readings in Tesla Field Units Query UNIT term lt units gt term n Refer to command for description Clear Zero Probe Command ZCLEAR term Resets the value stored from the ZPROBE command Zero Probe Command ZPROBE term Initiates the Zero Probe function Place the probe in zero gauss chamber before issuing this command Remote Operation 6 37 Lake Shore Model 455 Gaussmeter User s Manual This Page Intentionally Left Blank 6 38 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual CHAPTER 7 PROBES AND ACCESSORIES 7 0 GENERAL This chapter provid
99. User s Manual Model 455 DSP Gaussmeter Analog Local Output Autorange Probe III wo Select oc Zero Max Hold Intertace Alam Relay Units Homme DIE oe Lake Shore Lake Shore Cryotronics Inc 575 McCorkle Blvd Westerville Ohio 43082 8888 USA E mail Addresses sales lakeshore com service lakeshore com Visit Our Website At www lakeshore com Fax 614 891 1392 Telephone 614 891 2243 Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake Shore Cryotronics Inc No government or other contractual support or relationship whatsoever has existed which in any way affects or mitigates proprietary rights of Lake Shore Cryotronics Inc in these developments Methods and apparatus disclosed herein may be subject to U S Patents existing or applied for Lake Shore Cryotronics Inc reserves the right to add improve modify or withdraw functions design modifications or products at any time without notice Lake Shore shall not be liable for errors contained herein or for incidental or consequential damages in connection with furnishing performance or use of this material Revision 1 5 P N 119 040 13 May 2014 Lake Shore Model 455 Gaussmeter User s Manual LIMITED WARRANTY STATEMENT WARRANTY PERIOD THREE 3 YEARS 1 Lake Shore warrants that products manufactured by Lake Shore the Product will be free from defects in materials and workmanship for
100. a calibrated zero The offset is corrected using the Zero Probe function CALZ Zero Offset Calibration Constant Query Input CALZ lt type gt lt range gt term Format n n lt input gt 1 5 lt type gt 1 5 Returned lt value gt term Format nnnnnnn Refer to command for description CSMODE Configure Hall Current Source Mode Command Input CSMODE lt mode gt term Format n lt mode gt Specifies the hall current source mode Valid entries are 0 Current off 1 Normal mode current reversal 2 Positive current 3 Negative current Remarks Configures the hall current source mode The current output 100 mA 10 mA or 1mA is dependent on range see HALLCS CSMODE Configure Hall Current Source Mode Query Input CSMODE term Returned lt mode gt term Format n Refer to command for description Service 8 17 Lake Shore Model 455 Gaussmeter User s Manual HALLCS Hall Current Source Range Command Input HALLCS lt range gt term Format n lt range gt Specifies the hall current source range Valid entries are 1 100 mA range 2 10 mA range 3 1 mA range Remarks Ifa new probe is connected or the power is cycled on the instrument the hall current source will default back to the lowest current range range 3 1 mA If an invalid probe is attached to the instrument sending the HALLCS command will clear out the Invalid Probe message and the instrument will begin rea
101. ad the resistor using the DVM Store as TEMPDESIRED Connect a short across the temperature input of the Model 455 using a proper 4 lead connection Configure temperature current source for 1mA amplitude manual mode CALTEMP 1 3 Read the resistor using the Model 455 RDGTRES Store as TEMPOHMOFFSET Send the Offset Calibration Factor OCF to the Model 455 CALZ 5 3 TEMPOHMOFFSET Connect the 2 kQ resistor across the temperature input of the Model 455 using a proper 4 lead connection Read the resistor using the Model 455 RDGTRES Store as TEMPACTUAL Calculate the Gain Calibration Factor GCF as TEMPDESIRED TEMPACTUAL Test this factor to be 1 0 2 Send the Gain Calibration Factor GCF to the Model 455 CALG 5 3 lt GCF gt Read the resistor using the Model 455 RDGTRES Verify the reading to be TEMPDESIRED 0 05 Repeat steps 1 thru 12 for the remaining two current excitations using the following table guidelines Fipeced Gal Constant Verh Reading CALTEMP 1 3 1 00 2 DVM Measure 0 05 E E eg Ee bech ka ken W N 100uA CALTEMP 1 2 22 1 KQ 1 00 2 DVM Measure 0 05 CALTEMP 1 1 200 kQ 1 00 2 DVM Measure 0 05 14 Configure the Model 455 for temperature autoranging CALTEMP 0 3 15 Send the CALSAVE command to save the calibration constants into non volatile memory 8 11 4 Analog Output 2 and 3 Calibration This section will perform the actual calibration of Analog Output 2 and 3 This involve
102. ained together in one communication but they must be separated by a semi colon The total communication string must not exceed 255 characters in length A command string is issued by the computer and instructs the instrument to either perform a function or change a parameter setting When a command is issued the computer is acting as talker and the instrument as listener The format is lt command mnemonic gt lt space gt lt parameter data gt lt terminators gt Command mnemonics and parameter data necessary for each one is described in Section 6 3 Terminators must be sent with every message string A query string is issued by the computer and instructs the instrument which response to send Queries are issued similar to commands with the computer acting as talker and the instrument as listener The query format is lt query mnemonic gt lt gt lt space gt lt parameter data gt lt terminators gt Query mnemonics are often the same as commands with the addition of a question mark Parameter data is often unnecessary when sending queries Query mnemonics and parameter data if necessary is described in Section 6 3 Terminators must be sent with every message string Issuing a query does not initiate a response from the instrument A response string is sent by the instrument only when it is addressed as a talker and the computer becomes the listener The instrument will respond only to the last query i
103. and hold the Display key for approximately 4 seconds The display configuration screen appears as a prompt for display brightness Operating continuously at 100 brightness will shorten the life of the display A brightness setting of 75 is recommended for normal operation Use the A or W key to select brightness from 25 to 100 Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 4 5 UNITS To configure the field measurement units press Units The units setup screen appears as a prompt for the field measurement units Use the A or V key to select the field units Gauss Tesla Oersted or Amp meter Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display To configure the temperature measurement units press and hold the Units key for approximately 4 seconds The units setup screen appears as a prompt for the temperature measurement units Use the A or WV key to select the temperature units C or K Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display Operation 4 5 Lake Shore Model 455 Gaussmeter User s Manual 4 6 DC MEASUREMENT MODE To measure static or slowly changing fields press the DC key on the f
104. appears as a prompt to begin the copying process 5 2 Advanced Operation Lake Shore Model 455 Gaussmeter User s Manual Visually verify that a valid HMPEC cable is attached to the Model 455 Press Enter to copy the probe characteristics to the memory of the extension cable Press Escape to cancel the process and return to the normal display If a valid HMPEC cable is attached and Enter is pressed the following message will appear while the extension cable is programmed with the probe characteristics The process will be complete and the display will return to the normal display when this message disappears If an invalid HMPEC cable is attached and the probe matching process is attempted the following message will appear for approximately 5 seconds If this occurs verify that the cable is properly connected This message will also appear if an attempt is made to copy to a previously calibrated Lake Shore probe 5 2 HALL GENERATOR The Model 455 will operate with a discrete Hall generator when a suitable probe is not available Users can program nominal sensitivity and serial number into a blank connector HMCBL XX ordered separately to provide all gaussmeter functions except field and temperature compensation Note that unlike a fully calibrated probe the accuracy is affected by the Hall sensor linearity If the HMCBL cable is not loaded with sensitivity information or a 0 0 sensitivi
105. ata within a character This timing requires start and stop bits as part of each character so the transmitter and receiver can resynchronized between each character Half duplex transmission allows the instrument to be either a transmitter or a receiver of data but not at the same time Communication speeds of 9600 19200 38400 or 57600 Baud are supported The Baud rate is the only interface parameter that can be changed by the user Hardware handshaking is not supported by the instrument Handshaking is often used to guarantee that data message strings do not collide and that no data is transmitted before the receiver is ready In this instrument appropriate software timing substitutes for hardware handshaking User programs must take full responsibility for flow control and timing as described in Section 6 2 6 6 2 4 Character Format A character is the smallest piece of information that can be transmitted by the interface Each character is 10 bits long and contains data bits bits for character timing and an error detection bit The instrument uses 7 bits for data in the ASCII format One start bit and one stop bit are necessary to synchronize consecutive characters Parity is a method of error detection One parity bit configured for odd parity is included in each character ASCII letter and number characters are used most often as character data Punctuation characters are used as delimiters to separate different commands or pieces of data Two sp
106. ation on advanced operations for the Model 455 DSP Gaussmeter 5 1 PROBE MANAGEMENT The Model 455 has several capabilities that allow the best possible measurements with Lake Shore probes These firmware based features work in tandem with probe calibration and programming to ensure accurate repeatable measurements and ease of setup Many of the features require probe characteristics that are stored in non volatile memory located in the probe connector during calibration 5 1 1 Clear Probe Zero Calibration In some instances it may be useful to clear the results of the zero probe function This could be of value if the probe was zeroed improperly or if the user suspected that the probe was damaged By clearing the results of the zero probe function the instrument is returned to a known calibrated state To clear the results of the zero probe function press and hold the Zero Probe key for approximately 4 seconds The screen appears as a prompt for clearing the zero probe function Use the A or W key to select Yes or No Press Enter to accept the new selection and return to the normal display Press Escape to cancel the selection and return to the normal display 5 1 2 Probe Serial Number The serial number of the probe presently attached can be viewed from the display of the Model 455 This feature can also be used to check the programming of extension cables To view the serial number press the Probe key The following screen wi
107. auss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 350 00 kG 35 000 T 350 00 kOe 28 000 MA m 35 000 kG 3 5000 T 35 000 kOe 2 8000 MA m 3 5000 kG 350 00 mT 3 5000 kOe 280 00 kA m 350 00 G 35 000 mT 350 00 Oe 28 000 kA m 35 000 G 3 5000 mT 35 000 Oe 2 8000 kA m High Sensitivity Probe HSE Gauss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 35 000 kG 3 5000 T 35 000 kOe 2 8000 MA m 3 5000 kG 350 00 mT 3 5000 kOe 280 00 kA m 350 00 G 35 000 mT 350 00 Oe 28 000 kA m 35 000 G 3 5000 mT 35 000 Oe 2 8000 kA m 3 5000 G 350 00 uT 3 5000 Oe 280 00 A m Ultra High Sensitivity Probe UHS Gauss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 35 000 G 3 5000 mT 35 000 Oe 2 8000 kA m 3 5000 G 350 00 uT 3 5000 Oe 280 00 A m 350 00 mG 35 000 uT 350 00 mOe 28 000 A m 35 000 mG 3 5000 uT 35 000 mOe 2 8000 A m 4 12 RMS Operation Operation Lake Shore Model 455 Gaussmeter User s Manual RMS Operation Select Range and Autorange Continued For manual ranging press the Select Range key The range setup screen appears as a prompt for changing the range Use the A or V key to select from the available ranges Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new se
108. aussmeter User s Manual Visual Basic Serial Interface Program Setup The serial interface program works with Visual Basic 6 0 VB6 on an IBM PC or compatible with a Pentium class processor A Pentium 90 or higher is recommended running Windows 95 or better with a serial interface It uses the COM 1 communications port at 9600 Baud Use the following procedure to develop the Serial Interface Program in Visual Basic Start VB6 Choose Standard EXE and select Open Resize form window to desired size On the Project Menu click Components to bring up a list of additional controls available in VB6 Scroll through the controls and select Microsoft Comm Control 6 0 Select OK In the toolbar at the left of the screen the Comm Control will have appeared as a telephone icon Select the Comm control and add it to the form 7 Add controls to form 1 2 3 4 5 6 a b GC d Add three Label controls to the form Add two TextBox controls to the form Add one CommandButton control to the form Add one Timer control to the form 8 On the View Menu select Properties Window In the Properties window use the dropdown list to select between the different controls of the current project Labeli Command Label3 Label 10 Set the properties of the controls as defined in Table 6 7 11 Save the program 6 20 Remote Operation 12 Add code provided in Table 6 8 In the Code Editor window under the
109. ax errors command execution errors query errors operation complete Any or all of these events may be reported in the standard event summary bit through the enable register see Figure 6 2 The Standard Event Status Enable command ESE programs the enable register and the query command ESE reads it ESR reads and clears the Standard Event Status Register The used bits of the Standard Event Register are described as follows Power On PON Bit 7 This bit is set to indicate an instrument off on transition Command Error CME Bit 5 This bit is set if a command error has been detected since the last reading This means that the instrument could not interpret the command due to a syntax error an unrecognized header unrecognized terminators or an unsupported command Execution Error EXE Bit 4 This bit is set if an execution error has been detected This occurs when the instrument is instructed to do something not within its capabilities Query Error QYE Bit 2 This bit indicated a query error It occurs rarely and involves loss of data because the output queue is full Operation Complete OPC Bit 0 When OPC is sent this bit will be set when the instrument has completed all pending operations The operation of this bit is not related to the OPC command which is a separate interface feature Refer to Section 6 1 4 3 6 for more information re CaS Ao RE ER Status Register 128 64 32 16 8 4
110. ay write to or read from the Service Request Enable Register Each Status Byte summary bit is logically ANDed to the corresponding enable bit of the Service Request Enable Register When a Service Request Enable Register bit is set by the user and the corresponding summary bit is set in the Status Byte the RQS MSS bit of the Status Byte will be set which in turn sets the Service Request hardware line on the bus 6 4 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual seuser TOTS Tas Ta Ta EE Status Register Foon We ome exe Wei ave Net onc N ESR Used SS E Se Output TT Buffer Standard Event gt Status Enable 7 6 5 4 3 2 1 0 si Reger oe oe oe ESE ESE Used Used Used ame PON Power On Se CME Command Error EXE Execution Error QYE Query Error OPC Operation Complete Status Byte CA ees EE Bit Not Not Not Not RQS Generate service request Reset by serial poll S ele ED Mss Sie fees ire Joa E EEN Enable oe Not Not Not Not Operation OSB Operation Summary Bit Register Not Not Not 7 Master Summary Status Bi OBST NRE AC ESB Event Status Summary Bit MAV Message Available Summary Bit Operation ae oe oe ae Se Se ee Event 7 6 5 4 3 2 1 0 Bit Register Not Not Not Ste CSE STS om Dis n EE pa a no BH Ee Lat e Operation Event Enable 7 ES 4 3 2 11 0 Bit Register Se a SC 4 3
111. b 10 Mx 10 lines Flux density is the number of flux lines passing perpendicular through a plane of unit area A The symbol for flux density is B where B AA The cgs system measures flux density in gauss G where 1 G 1 Mx cm The SI system measures flux density in tesla T where 1 T 1 Wb m Flux density is important when magnet systems concentrate flux lines into a specific area like the pole pieces in an electromagnet Forces generated on current carrying wires like those in a motor armature are proportional to flux density Saturation of magnetic core material is also a function of flux density 2 2 2 How Flux Density B Differs from Magnetic Field Strength H Flux density is often confused with magnetic field strength Magnetic field strength is a measure of the force producing flux lines The symbol for magnetic field strength is H In the cgs system it is measured in oersteds Oe In the SI system it is measured in amperes per meter A m 10e 79 58 A m Flux density and magnetic field strength are related by the permeability u of the magnetic medium B pH Permeability is a measure of how well a material makes a path for flux lines The confusion of flux density and magnetic field strength is also related to permeability In the cgs system the permeability of air of vacuum is 1 Therefore 1 G 1 Oe or B H in air Many people incorrectly assume therefore that in the cgs system B H at all times Adding t
112. be temperature can also affect readings Refer to the two separate temperature coefficients listed on the specification sheet The High Stability HST probes exhibit a low temperature coefficient of gain due to the inherent thermal stability of the materials used in its construction Probe readings are dependent on the angle of the sensor Hall sensor in relation to the magnetic field Maximum output occurs when the flux vector is perpendicular to the plane of the sensor This is the condition that exists during factory calibration The greater the deviation from orthogonality from right angles in either of three axes the larger the error of the reading For example a 5 variance on any one axis causes a 0 4 error a 10 misalignment induces a 1 5 error etc See Figure 3 5 Tolerance of instrument probe and magnet must be considered for making critical measurements The accuracy of the gaussmeter reading is typically 0 05 of reading and 0 005 of range but the absolute accuracy readings for gaussmeters and Hall probes is a difficult specification to give because all the variables of the measurement are difficult to reproduce Differences in alignment and positioning will degrade measurement accuracy and repeatability Finally the best probes have an accuracy of 0 10 This implies that the absolute accuracy of a magnetic field measurement will not reliably be better than 0 10 of reading and is likely to be 0 20 29 3 B 13 4 45
113. been corrupted Recalibration is required for accurate measurements Press the Escape and Enter keys simultaneously to clear the message The instrument can still be used but it may not be operating within specifications Measurement No Probe There is no probe attached or the attached probe is damaged The detected probe is not recognized as a valid Model 455 probe Press Enter to Invalid Probe continue Incompatible Probe A previous generation probe has been attached Press Enter to continue Measurement uses only nominal probe sensitivity Accuracy not guaranteed The measured field is larger than the range Increase the measurement range te Check probe zero Probe may be damaged SUNDER The temperature sensor reading is less than the minimum temperature table entry SOVER The temperature sensor reading is greater than the maximum temperature table entry Illegal Operation LOCKED A key operation was attempted with the keypad locked Max Not Available Max Hold and Peak do not operate together With Peak Invalid MPEC Cable Improper cable attached during the HMPEC programming process Invalid MCBL Cable Improper cable attached during the HMCBL programming process Service 8 3 Lake Shore Model 455 Gaussmeter User s Manual 8 7 ELECTROSTATIC DISCHARGE Electrostatic Discharge ESD may damage electronic parts assemblies and equipment ESD is a transfer of electrostatic
114. bsolute accuracy of a magnetic field measurement will not reliably be better than 0 10 of reading and is likely to be 0 15 or higher 29 3 B 13 4 45 6 0 3 4 20 3 15 0 4 5 0 0 Error Deviation from perpendicular a Effect of angular variations on percentage of reading error where percent error 1 cos a 100 Figure 7 1 Effect Of Angle On Measurements 7 4 Probes and Accessories Lake Shore Model 455 Gaussmeter User s Manual 7 3 4 Probe Specifications Terminology used in Figures 7 2 thru 7 8 are defined as follows Definition of Probe Terminology Usable Full Scale Ranges Vs Probe Type Type HST 3 HST 4 HSE UHS A Distance from tip to center line of active area 35G SC B Magnetic flux density vector for reading Usabl 35G 35G 35G 35 mG HST High Stability Probe E e l 350G 350G 350G 350mG HSE High Sensitivity Probe Ranges 3 5 kG 3 5 kG 3 5 kG 3 5 G UHS Ultra High Sensitivity Probe 35KG 35KG 35kG 35 G 350 kG GAMMA PROBE k L Zoll horn oi ue od mpa vourra ma a e hada ch T n iha o ha Emih une heda moud ap ioc oon be ZE 8 WA e eau Hh hem ulg ee ey Droen Peed eee Pm Il O ma aya hu ig pon opm hen mkia ma bah d a lrg ee Emman Au deggie lhon Ion h ie mran p Sabet enh P he a F Engh o he pra moba a 9 1253 ch e Corrected Operating Tempest C oeffident Contain equency ModelHa
115. ced in AC fields These eddy currents oppose the field and cause measurement error The error magnitude is proportional to frequency and is most noticeable above 800 Hz Non metal Stem Non metal stems are required for higher frequency AC fields and for measuring pulse fields but they obviously provide less protection than metal stems Fiberglass epoxy is a common non metal stem material or the Hall effect sensor can be left exposed on its ceramic substrate These materials are not conductive so eddy currents do not limit their frequency range but other factors may Be careful to read and understand the frequency specification of both the probe and gaussmeter when choosing a non metal probe A WARNING None of these probe types are suitable for direct exposure to high voltage The possibility exists for damage to equipment or injury to the operator if the probe is exposed to high voltage Gradient Probe selection would be easier if all fields were large and uniform but that is seldom the case because most fields are limited in volume and contain gradients changes in magnitude Hall effect probes measure an average magnitude over their active area making it necessary to understand the relationship between active area and field gradients Severe field gradients are always experienced as the active sense element is moved away from a permanent magnet pole making it important to know the distance between the active area and probe tip The distance between
116. ceeceeceeeeeeeaeeeeaeeseeeeecaeeeseaeeseaeeseeeessaeeseeeeseeeeeas 7 2 7 3 2 Radiation Effects on Gaussmeter Probes essssseeseessessissristriesttntttntttnnttnnnnnstnnen neen nnnn 7 4 7 3 3 Probe Accuracy Considerations eessesseeseeesiesiesiiettisttinttintttntttntttnnttnntnnntnnnnnnnnn nnn nnna 7 4 7 3 4 Probe Specifications aii ne raaa A Arie E E a E PANE A AE AEAEE ge a APES SAE AEAEE 7 5 7 4 PROBE ACCESSORIE S ea eae a e e aa a a a ine AS te 7 9 7 5 HALL GENERATOR E A A T A 7 10 7 5 1 Hall Generator Handling 7 10 7 5 2 Hall Generator Lead Wires ege ces savetsed eg trann aa aaa a aara aAa aE raia AE aiat 7 10 7 5 3 Using a Hall Generator with the Model 455 ssssssssssssssessrnssrnssrnesrnssrnssinssrnssrnssrnssrnssrnssnns 7 10 7 5 4 Attachment To A User Programmable Cabie 7 11 7 5 5 Hall Generator Specifications cceccceecceeeence cece eeeeeeeeneeceeeeeeaaeseeaaesseneeseaeeesaeseeaeeeseeeess 7 12 7 6 HELMHOLTZ COIL LOW FIELD STANDARD 7 15 7 7 REFERENCE MAON ET Oa eee a ia a a a a ae aaah eae 7 17 7 8 ZERO ee E WE 7 18 8 SERVICE EE 8 1 8 0 GENERAL ei er rege eit cette id oe tat he eh eee he dal 8 1 8 1 CONTACTING LAKE SHORE CRYOTRONICS eects estes eeeeeeseeeeeaeeteneeseeeeess 8 1 8 2 RETURNING PRODUCTS TO LAKE GHORE nnn 8 1 8 3 FUSE DRAWER cardi eles va cise Mee Ee SEENEN AE 8 2 8 4 LINE VOLTAGE SELECTION apinain uien aoa aan raada aea aaee iana aa ENEE 8 2 8 5 FUSE REPLACEMENT minarine riiai n ii i eiia a i
117. computer interface but the display will update at 5 readings per second independent of filter configuration The resolution can be set from 3 to 53 4 digits The table below shows how the resolution is related to the reading rate and the frequency response Display Setting Number of Digits 3 dB Frequency Maximum Reading Rate 3 3 100 Hz 30 readings second 4 4 10 Hz 30 readings second 5 5 1 Hz 10 readings second To configure the resolution press and hold the DC key for approximately 4 seconds The following screen appears as a prompt for DC resolution setting Use the A org key to select from 3 4 or 5 digits Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 4 6 3 DC Operation Zero Probe The zero probe function cancels out the zero offset of the probe or small DC magnetic fields It is normally used in conjunction with the zero gauss chamber but may also be used with an unshielded probe registering Earth s local magnetic field The zero probe function should be used any time a probe is changed when operating conditions such as temperature change significantly and periodically during normal use To cancel large magnetic fields use the Relative function NOTE For best results allow the instrument and probe to warm up for at least 5 minutes before zeroing the probe and at least 30 minutes
118. configurations so that it can be operated from line power anywhere in the world The nominal voltage and voltage range of each configuration is shown below The recommended setting for 230 V operation is 240 V Nominal Minimum Maximum 100 V 90 V 106 V 120 V 108 V 127 V 220 V 198 V 233 V 240 V 216 V 254 V Verify that the AC line voltage indicator in the fuse drawer window shows the appropriate AC line voltage before turning the instrument on The instrument may be damaged if it is turned on with the wrong voltage selected Instructions for changing the line voltage configuration are given in Section 8 4 3 3 2 Line Fuse and Fuse Holder The line fuse is an important safety feature of the Model 455 If a fuse ever fails it is important to replace it with the value and type indicated on the rear panel for the line voltage setting The letter T on the fuse rating indicates that the instrument requires a time delay or slow blow fuse Fuse values should be verified any time line voltage configuration is changed Instructions for changing and verifying a line fuse are given in Section 8 5 3 3 3 Power Cord The Model 455 includes a 3 conductor power cord that mates with the IEC 320 C14 line cord receptacle Line voltage is present on the two outside conductors and the center conductor is a safety ground The safety ground attaches to the instrument chassis and protects the user in case of a component failure A CE approve
119. d ceeeeeeee 6 28 Analog Output 3 Parameter Ouer 6 29 Analog Output 3 Data Ouer 6 29 Auto Range Command Auto Range Query 6 29 RS 232 Baud Rate Cmd 6 29 RS 232 Baud Rate Query eeeceesceseeeeeteeeeeereeee 6 29 Audible Alarm Beeper Cmd eseeceeeeeeeeee 6 29 Audible Alarm Beeper Query csceeseseeeeeeee 6 29 Display Brightness Cd 6 29 Display Brightness Query 6 30 Factory Defaults Cd 6 30 Display Configuration Cd 6 30 Display Configuration Ouerg 6 30 IEEE 488 Interface Parameter Cmd s sssseeeeese 6 30 TEEE 488 Interface Parameter Query s 0s0s000 6 30 Keypad Status Query ccceceeseeseeseeseeseeneeeeeeeeeee 6 30 Front Panel Keyboard Lock Cmd s sssseseseeeeeeeee 6 31 Front Panel Keyboard Lock Ouer 6 31 Max Hold Cid issscss aie vest asenisre sds eacseanasiiaae 6 31 Max Hold Ouer 6 31 Max Hold Reset Cmd ucts eeeeees 6 31 Command MODE MODE OPST OPSTE OPSTE OPSTR PKRST PRBFCOMP PRBFCOMP PRBSENS PRBSNUM PRBTCOMP PRBTCOMP RANGE RANGE RDGFIELD RDGMODE RDGMODE RDGFRQ RDGMNMX RDGOHM RDGPEAK RDGREL RDGTEMP REL REL RELAY RELAY RELAYST RELSP RELSP TUNIT TUNIT TYPE UNIT UNIT ZCLEAR ZPROBE Function Page Remote Interface Mode Cmd eee 6 31 Remote Interface Mode Query eee 6 31 Operational Status Query 0 eects 6 32 Operational Status Enable Cmd 0 0 6 32 Operational Status Enable Query ee 6 3
120. d the readings are filtered The data is then transferred to the microprocessor where the readings can be sent to the display or out to the computer interface The Model 455 has three different analog outputs each one providing different information Analog Output 1 is a pure analog output being taken just before the A D and is corrected for nominal probe sensitivity In wide band AC mode this represents the actual signal being generated by the Hall sensor It is not as useful in narrow band AC and DC modes where the output is going to contain the 5 kHz excitation frequency Analog Output 2 is generated from a high speed D A converter controlled by the DSP This output is generated from the data after the product detector and is a representation of the actual field being measured A measured DC field will appear as a DC signal and an AC field will appear as an AC signal Analog Output 2 is corrected for nominal probe sensitivity and probe zero offset Analog Output 3 is generated from a D A converter controlled by the microprocessor This output has many different modes of operation including manual output and to output a voltage that is proportional to the field being read including probe zero offset field compensation and temperature compensation If the instrument is set up in AC mode then the output is a DC voltage proportional to the RMS value of the field Analog Output 2 Analog Output 1 Output 3 Display Computer
121. d all fuses Accessories Included G 106 253 T O mating connector G 106 264 T O mating connector shell 4060 Zero gauss chamber MAN 455 Model 455 Gaussmeter user manual Accessories Available 4005 1 m 3 ft long IEEE 488 GPIB computer interface cable assembly includes extender required for simultaneous use of IEEE cable and auxiliary I O connector 4065 Large zero gauss chamber for Gamma probe RM Rack mount kit for one 1 2 rack gaussmeter in 483 mm 19 in rack RM 2 Rack mount kit for two L rack gaussmeter in 483 mm 19 in rack HMCBL 6 User programmable cable with EEPROM 6 ft HMCBL 20 User programmable cable with EEPROM 20 ft HMPEC 10 Probe extension cable with EEPROM 10 ft calibrated HMPEC 10 U Probe extension cable with EEPROM 10 ft uncalibrated HMPEC 25 Probe extension cable with EEPROM 25 ft calibrated HMPEC 25 U Probe extension cable with EEPROM 25 ft uncalibrated HMPEC 50 Probe extension cable with EEPROM 50 ft calibrated HMPEC 50 U Probe extension cable with EEPROM 50 ft uncalibrated HMPEC 100 Probe extension cable with EEPROM 100 ft calibrated HMPEC 100 U Probe extension cable with EEPROM 100 ft uncalibrated Calibration Service CAL N7 DATA New instrument calibration for Model 455 475 with certificate and data CAL 455 Instrument recalibration with certificate CAL 455DATA Instrument recalibration with certificate and data Specifications are subject to change without notice Introduction 1 7
122. d power cord is included with instruments shipped to Europe a domestic power cord is included with all other instruments unless otherwise specified when ordered Always plug the power cord into a properly grounded receptacle to ensure safe operation of the instrument 3 3 4 Power Switch The power switch is part of the line input assembly on the rear panel of the Model 455 and turns line power to the instrument On and Off When the circle is depressed power is Off When the line is depressed power is On Installation 3 3 Lake Shore Model 455 Gaussmeter User s Manual 3 4 PROBE INPUT CONNECTION WARNING Probes used with the gaussmeter have conductive parts Never probe near exposed live voltage Personal injury and damage to the instrument may result The Lake Shore probe plugs into the 15 pin D sub connector on the rear panel Align the probe connector with the rear panel connector and push straight in to avoid bending the pins For best results secure the connector to the rear panel using the two thumbscrews A tight connector keeps the cable secure and prevents interference Refer to Section 3 5 for additional probe considerations An Electrically Erasable Programmable Read Only Memory EEPROM is included in each probe The EEPROM stores specific information that the gaussmeter requires for operation The information includes serial number probe sensitivity and field compensation data When a new probe is connected the instrume
123. de gt is 2 this parameter represents the data at which the analog output reaches 100 output if bipolar or 0 output if unipolar 350 kG lt high value gt If lt mode gt is 2 this parameter represents the data at which the analog output reaches 100 output 350 kG lt manual value gt If lt mode gt is 3 this parameter represents the percent output of the analog output between 100 and 100 lt voltage limit gt Specifies absolute maximum analog output voltage 1 to 10 V Example ANALOG 2 2 25 000E 3 250 000E 3 0 00000E 00 10 term Configures Analog Output 3 for user defined mode bipolar polarity 100 out at 25 mG 100 out at 250 mG and an absolute maximum output voltage of 10 V The manual value is ignored in this mode 6 28 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual ANALOG Analog Output 3 Parameter Query Input ANALOG term Returned lt mode gt lt polarity gt low value gt lt high value gt manual value gt lt voltage limit gt term Format n n tnnn nnnE nn t nnn nnnE nn tnnn nnnEtnn Refer to command for definition AOUT Analog Output 3 Data Query Input AOUT term Returned lt percent gt term Format t nnn nnnEtnn Remarks Returns the percentage of output of Analog Out 3 AUTO Auto Range Command Input AUTO lt off on gt term Format n lt off on gt Specifies autorange on or off 0 Off 1 On Example AUTO 1 term Turns on the autorange feature AUTO
124. dg s 30 rdg s 30 rdg s DC accuracy 0 075 of reading 0 005 of range DC temperature coefficient 0 01 of reading 0 003 of range per C 1 4 Introduction Specifications Continued AC RMS Measurement Probe Type 4 4 digit Ranges resolution HST Probe 350 kG 000 01 kG 35 kG 00 001 kG 3 5kG 0 0002 kG 350 G 000 02 G 35G 00 020 G HSE Probe 35 kG 00 001 kG 3 5 kG 0 0001 kG 350 G 000 02 G 35 G 00 002 G 3 5 G 0 0020 G UHS Probe 35 G 00 001 G 3 5 G 0 0002 G 350 mG 000 02 mG 35 mG 00 020 mG Lake Shore Model 455 Gaussmeter User s Manual Measurement resolution RMS noise floor Indicated by value in above table for shorted input Display resolution Indicated by number of digits in above table Max reading rate 30 rdg s AC accuracy 1 of reading gt 1 of full scale range 10 Hz to 20 kHz AC frequency range 10 Hz to 1 kHz narrow band mode 135 Hz to 20 kHz wide band mode Peak Measurement Probe Type 4 4 digit Ranges resolution HST Probe 350 kG 000 01 kG 35 kG 00 001 kG 3 5kG 0 0002 kG 350 G 000 02 G 35G 00 020 G HSE Probe 35 kG 00 001 kG 3 5 kG 0 0001 kG 350 G 000 02 G 35 G 00 002 G 3 5 G 0 0020 G UHS Probe 35 G 00 001 G 3 5 G 0 0002 G 350 mG 000 02 mG 35 mG 00 020 mG Measurement resolution RMS noise floor Indicated by value in above table for periodic mode and shorted input Display resolution Indicated by number of digits in above
125. ding in ohms HALLCS Hall Current Source Range Query Input HALLCS term Returned lt range gt term Format n Refer to command for description KEYST Last Key Press Query Input KEYST term Returned lt code gt term Format nn Refer to command for description 00 no key pressed since last query 08 Enter 16 6 01 09 Relative 17 7 02 Up 10 Reset 18 8 03 Escape 11 1 19 9 04 Max Hold I2 2 20 0 05 Peak 13 3 21 DC 06 14 4 22 RMS 07 Down 15S 99 multiple keys pressed simultaneously MOUT Analog Output 2 Setup Command Input MOUT lt mode gt lt setting gt term Format n tnnnnnnn lt mode gt Specifies the operating mode Analog Output 2 Valid entries are 0 Normal mode output follows reading 1 Manual setting mode lt setting gt Analog Output 2 manual setting value 100 Remarks This command is used to set Analog Output 2 to a manual setting value so that the output can be calibrated Default is mode 0 normal MOUT Analog Output 2 Setup Query Input MOUT term Returned lt mode gt lt setting gt term Format n tnnnnnnn Refer to command for description RDGTRES Temperature Sensor Resistance Reading Query Input RDGTRES term Returned lt thermistor resistance gt term Format nnnnnnn 8 18 Service Magnetic flux density Magnetic po
126. e Off to On transition will capture the field reading to use as the setpoint If a User Defined setpoint is selected the following screen appears as a prompt for entering the setpoint after the Relative On display disappears Use the data entry keys to enter the high setpoint between 350 kG or equivalent depending on selected field units Enter the numeric value first Press Enter to accept the new value and advance to the units multiplier Use the A or V key to select a units multiplier of u m blank k or M depending on selected field units Press Enter to accept the new selection and return to the normal display Press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display 4 8 7 Peak Operation Analog Output 1 and 2 In Peak measurement mode Analog Output 1 is a real time analog signal proportional to the magnetic field and scaled to 3 5 volts for full scale of selected range except for the lowest range which is scaled to 0 35 volts for full scale range The output has a frequency range of 5 Hz to 20 kHz This output will be useful in both periodic and pulse measurements for viewing the shape of the field Analog Output 2 provides a live AC voltage proportional to the AC magnetic field going into the peak capture algorithm This voltage is corrected for the nominal sensitivity of the probe The output is updated at a rate of 40 000 readings per
127. e Sub Form_Load Add the code to this subroutine as shown in Table 6 5 11 Save the program 12 Run the program The program should resemble the following IEEE Interface Program Type exit to end program Command Biel Es Response 13 Type in a command or query in the Command box as described in Section 6 1 5 5 14 Press Enter or select the Send button with the mouse to send command 15 Type Exit and press Enter to quit 6 14 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual Table 6 5 Visual Basic IEEE 488 Interface Program Public gSend As Boolean Global used for Send button state Private Sub cmdSend_ Click gSend True End Sub Routine to handle Send button press Set Flag to True Private Sub Form Load Dim strReturn As String Dim term As String Dim strCommand As String Dim intDevice As Integer frmIEEE Show term Chr 13 amp Chr 10 strReturn Call ibdev 0 12 0 T10s 1 amp H140A intDevice Call ibconfig intDevice ibcREADDR 1 Main code section Used to return response Terminators Data string sent to instrument Device number used with IEEE Show main window Terminators are lt CR gt lt LF gt Clear return string Initialize the IEEE device Setup Repeat Addressing Do Do Wait loop DoEvents Give up processor to other events Loop Until gSend True Loop until Send button pressed g
128. e probe serial number PRBTCOMP Probe Temperature Compensation Command Input PRBTCOMP lt off on gt term Format n lt off on gt Specifies Probe Temperature compensation off or on Valid entries 0 off 1 on Example PRBTCOMP 1 term Field Measurement is compensated for present probe temperature PRBTCOMP Probe Temperature Compensation Query Input PRBTCOMP term Returned lt off on gt term Format n Refer to command for description RANGE Field Range Command Input RANGE lt range gt term Format n lt range gt Specifies range from lowest to highest 1 5 Field values are probe dependent Example RANGE 4 term Sets the present range to 4 RANGE Field Range Query Input RANGE term Returned lt range gt term Format n Refer to command for description RDGFIELD Field Reading Query Input Returned Format Remarks RDGFIELD term lt field gt term nnn nnnE nn Returns the field reading in a format based on the present units This is valid for DC or RMS Remote Operation 6 33 Lake Shore Model 455 Gaussmeter User s Manual RDGMODE Input Format Example Measurement Mode Command RDGMODE lt mode gt lt dc resolution gt lt rms measurement mode gt lt peak mode gt lt peak disp gt term n n n n n lt mode gt Specifies the measurement mode 1 DC 2 RMS 3 peak lt dc resolution gt DC operating resolution in number of digits 1 3 dig
129. e string at one time including terminators Send only one simple command at a time until communication is established Be sure to spell commands correctly and use proper syntax Oy eR Attempt both Talk and Listen functions If one works but not the other the hardware connection is working so look at syntax terminators and command format 7 Ifonly one message is received after resetting the interface check the repeat addressing setting It should be enabled Old Installation No Longer Working 8 Power instrument off then on again to see if it is a soft failure 9 Power computer off then on again to see if the IEEE card is locked up 10 Verify that the address has not been changed on the instrument during a memory reset 11 Check all cable connections Intermittent Lockups 12 Check cable connections and length 13 Increase delay between all commands to 50 ms to make sure instrument is not being over loaded 6 16 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual 6 2 SERIAL INTERFACE OVERVIEW The serial interface used in the Model 455 is commonly referred to as an RS 232C interface RS 232C is a standard of the Electronics Industries Association EIA that describes one of the most common interfaces between computers and electronic equipment The RS 232C standard is quite flexible and allows many different configurations However any two devices claiming RS 232C compatibility cannot
130. easily break the Hall generator Broken Hall generators are not repairable Hall Generators are very fragile and require delicate handling The ceramic substrate used to produce the Hall sensor is very brittle Use the leads to move the Hall generator Do not handle the substrate The strength of the lead to substrate bond is about 7 ounces so avoid tension on the leads and especially avoid bending them close to the substrate The Hall Generator is also susceptible to bending and thermal stresses 7 5 2 Hall Generator Lead Wires Lake Shore Hall generators except Models HGCA 3020 and HGCT 3020 have 34 AWG solid copper lead wire with poly nylon insulation and have the following color coded lead configuration Red ar Green lg Blue WH Clear vy Input Control Current Output Hall otage The Model HGCA 3020 and HGCT 3020 Hall generators have 34 AWG stranded copper lead wire with Teflon insulation and have the following color coded lead configuration Red l See SC Input Control C urrenty Blue y Yellow Au Output Hall Vota gej 7 5 3 Using a Hall Generator with the Model 455 Connecting a Hall generator to the Model 455 requires a Lake Shore Model HMCBL 6 or 20 Cable Assembly sold separately The cable has a 15 pin D sub connector on one end and four leads on the other The 4 leads illustrated in Figure 7 9 correspond to the 4 leads on the Hall generators given in Section 7 5 2 Each Hall gene
131. easurement performance when used along with Lake Shore Hall probes Firmware based features work in tandem with the probe s calibration and programming to ensure accurate repeatable measurements and ease of setup Many of the features require probe characteristics that are stored in the probe connector s non volatile memory Probe Field Compensation The Hall effect devices used in gaussmeter probes produce a near linear response in the presence of magnetic field The small nonlinearities present in each individual device can be measured and subtracted from the field reading Model 455 probes are calibrated in this way to provide the most accurate DC readings Probe Temperature Compensation Hall effect devices show a slight change in sensitivity and offset with temperature Probe temperature effects can be measured and subtracted out of field readings A temperature sensor in the probe tip relays real time temperature to the gaussmeter enabling compensation Although temperature effects contribute only a small fraction of the overall probe measurement accuracy temperature compensation will often improve measurement and control stability Probe Temperature Display The gaussmeter can display the probe s temperature in C along with a field reading when using a probe that includes a temperature sensor Frequency Display When operating in RMS mode the gaussmeter can display the frequency of the measured AC field along with a field reading 1 2
132. ecial ASCII characters carriage return CR OD and line feed LF OAH are used to indicate the end of a message string Table 6 6 Serial Interface Specifications Connector Type 9 pin D style connector plug Connector Wiring DTE Voltage Levels EIA RS 232C Specified Transmission Distance 50 feet maximum Timing Format Asynchronous Transmission Mode Half Duplex Baud Rate 9600 19200 38400 57600 Handshake Software timing Character Bits 1 Start 7 Data 1 Parity 1 Stop Parity Odd Terminators CR ODH LF OAH Command Rate 20 commands per second maximum 6 2 5 Message Strings A message string is a group of characters assembled to perform an interface function There are three types of message strings commands queries and responses The computer issues command and query strings through user programs the instrument issues responses Two or more command strings or queries can be chained together in one communication but they must be separated by a semi colon The total communication string must not exceed 255 characters in length A command string is issued by the computer and instructs the instrument to perform a function or change a parameter setting The format is lt command mnemonic gt lt space gt lt parameter data gt lt terminators gt Command mnemonics and parameter data necessary for each one is described in Section 6 3 Terminators must be sent with every message string 6 18 Remote Operatio
133. ed feature is enabled In addition to the display annunciators there are three LED annunciators to the right of the display 4 2 Operation Lake Shore Model 455 Gaussmeter User s Manual Display and LED Annunciators Continued Display Annunciators i Indicates that the Relative measurement mode is on Indicates the Relative setpoint value LED Annunciators Relative Alarm Remote Indicates that the Relative measurement mode is on On steady when the alarm feature is on blinks when the alarm is active Indicates that the instrument is under remote control of the computer interface 4 3 KEYPAD DEFINITION The Model 455 has 22 keys separated into 3 groups on the instrument front panel 4 3 1 Local Analog Output Display Autorange Zero Probe Interface Alarm Relay Units Select Range Probe 0 9 Up a Down Escape Enter DC RMS Max Hold Peak Relative Reset Key Descriptions Returns the instrument to Local mode if in Remote Chapter 6 Setup Analog Output 3 Configure bottom line of display Turns Auto Range feature ON and OFF Zeros or nulls effects of ambient low level fields from the probe Setup computer interface parameters Chapter 6 Turns Alarm feature ON and OFF and setup alarm parameters Setup Relay feature Configure units of measurement for Field and Temperature if available Manually selects field measurement range Setup and view Probe parameters Extension cable p
134. eesicnedanes doreetlageastaesartavavedaetvdsiratsaeanidees 4 8 Magnitude or Algebraic asieran eepe aaae araa eE aaa a ata Aaea ea Kaaa aa Ka aAA OA en a Raae 4 8 Elia RETTEN ne ME 4 10 DG Operation EE 4 10 DC Operation Relative ccccccccceeeeseeeeeeeeceeeeeeeaeseeaeeseeeeeceaeeeeeaesseeeeeeeeeeseaeeeeaesseaeesseeeess 4 10 DC Operation Analog Output 1 and 3 4 11 RMS MEASUREMENT MODE 4 12 RMS Operation Select Range and Autorange sssseseseeessieserssriesrissrissrissrrnerinsrienrnee 4 12 RMS Measurement Band 4 13 RMS Operation Frequency Measurement sssssssssissrresriesrresrssrissriesristrinsnnsrnnsnnsne e 4 13 RMS Operation Reading Rate ccccceecsceceeeceseeeeeeeeseeeeeceaeeeseaeeseneeseeeeesaeeesaeseeaeeeeeeeess 4 13 RMS Operation Max Hold 4 14 Max Min Display Setting EE 4 14 RMS Operation R Set cccccccecceeeeeeeeeeeeeeeeeeeeceaeeeeeeeceaeeecaaeeesaaesseaeesseeeesaeeeeaaesseneeeneeeess 4 14 RMS Operation Helattve neet nesrnsstrsstrsstrsstnsstnsstnsstnnstensresstensnnnsnnnnnnnnnnnnt 4 14 RMS Operation Analog Output 1 and 3 4 15 PEAK MEASUREMENT MODE ssseessesseesseesissrirtrsrtrtttnttntttnustnnstnnsttnntrnstnnstnsstnnsrnn nts 4 16 Peak Operation Select Hange 4 16 Peak Operation Periodic PulSe Getup e 4 17 Peak Operation Display Setting 0 cccccceceeeceseeeeeeeeeceeeeeceaeeeeeaeeeeaeeseceeeseaeeesaeeeeaeeseeneess 4 17 Peak Operation Heset nt 4 17 Peak Operation Frequency Measurement
135. efficient ceramic package Active area approximate 0 040 inch diameter circle 0 040 inch diameter circle 0 040 inch diameter circle Nominal control current Nominal control current Icn ing mA s100mA mA s100mA mA Ee continuous current pee mA ee mA ee mA non heat sinked Magnetic sensitivity Ic 7 5 to 12 5 mV kG 0 55 to 1 05 mV kG 6 0 to 10 0 mV kG nominal control current Maximum linearity error 1 0 RDG 1 RDG 0 30 RDG sensitivity versus field 10 to 10 kG 30 to 30 kG 10 to 10 kG 1 5 RDG 1 25 RDG 100 to 100 kG 30 to 30 kG Zero field offset voltage Ic 100 uV max 50 uV max 75 uV max nominal control current Operating temperature range temperature range Operating temperature range 40 to 100 C 40 to 100 C 40 40t0 100 C o 40t0 100 C o C Mean temperature coefficient 0 08 C max 0 005 C max 0 04 C max of magnetic sensitivity Mean temperature coefficient 1 u V C max 0 4 wV C max 0 3 uV C of offset Ic nominal control current Mean temperature coefficient 0 18 C approx 0 15 C approx 0 18 C approx of resistance Leads 34 AWG copper with poly 34 AWG copper with poly 34 AWG copper with poly nylon insulation nylon insulation nylon insulation 7 14 Probes and Accessories Lake Shore Model 455 Gaussmeter User s Manual 7 6 HELMHOLTZ COIL LOW FIELD STANDARDS Lake Shore offers three Helmholtz coils
136. el 455 Gaussmeter User s Manual If the relative mode is configured to use the present field as the setpoint the Off to On transition will capture the field reading to use as the setpoint If a User Defined setpoint is selected the following screen appears as a prompt for entering the setpoint after the Relative On display disappears Use the data entry keys to enter the high setpoint between 350 kG or equivalent depending on selected field units Enter the numeric value first Press Enter to accept the new value and advance to the units multiplier Use the A or V key to select a units multiplier of u m blank k or M depending on selected field units Press Enter to accept the new selection and return to the normal display Press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display NOTE The Relative Setpoint entry screen also appears under the press and hold feature of the Relative key if relative is configured for a user defined setpoint 4 6 7 DC Operation Analog Output 1 and 2 In the DC measurement mode the signal available at Analog Output 1 may only be useful as a verification of the Model 455 measurement hardware The signal contains the 5 kHz modulation of the current source making it difficult to use as an accurate field representation Analog Output 2 provides a DC voltage proportional to the displayed field through a high speed D A
137. elmholtz Coil Probes and Accessories 7 15 Lake Shore Model 455 Gaussmeter User s Manual Banana Jacks s Input CC foc e 3 5 _ _ 5 4 Helmholtz_6 bmp Helmholtz_12 bmp Figure 7 15 Model MH 12 Helmholtz Coil 7 16 Probes and Accessories Lake Shore Model 455 Gaussmeter User s Manual 7 7 REFERENCE MAGNETS Magnetic reference standards containing highly stable permanent magnets have been in use for many years The highest quality units are usually shielded from external magnetic effects and use Alnico V or VI magnets for long term stability They are supplied in both transverse flat and axial configurations Typical transverse reference magnets are usually stabilized for use at ambient temperatures between 0 50 C and have nominal temperature coefficients of about 0 02 C Because the temperature coefficient is negative the field strength will be reduced as the temperature rises Since these references are temperature cycled during manufacture their change with temperature is predictable and retraceable they will always return to a known value at any specific ambient temperature The high permeability shell which surrounds the reference magnet serves two function 1 it shields the magnet from external field and 2 serves as the flux return path Physical damage to the outer shell can cause a permanent change in the gap flux density Reference magnets sho
138. entry keys to enter the 3 digit lock code default 123 The instrument returns to the normal display with the keypad locked To unlock the instrument keypad press and hold the Enter key for 5 seconds The following screen appears as a prompt for the 3 digit lock code Use the data entry keys to enter the 3 digit lock code default 123 The instrument returns to the normal display with the keypad unlocked 4 26 Operation Lake Shore Model 455 Gaussmeter User s Manual 4 14 DEFAULT PARAMETER VALUES It is sometimes desirable to reset instrument parameters to their default values This data is stored in EEPROM memory Instrument calibration is not affected by this operation The firmware version date is also displayed during this sequence To reset the EEPROM memory or view the firmware revision dates press and hold the Escape key for 5 seconds The following screen appears to show the firmware revision date Press Enter to continue to the next setting screen Press Escape to return to the normal display The next screen appears as a prompt for returning the instrument parameters to default values Default parameter values are listed in Table 4 1 Use the or w keys to select Yes for default values and No to continue without changing the parameter values Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal
139. ept the new selection and continue to the next setting screen Press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display The next analog setup screen appears as a prompt for the high setpoint value This value represents the reading at which the Analog Output 3 will be 10 volts Operation 4 23 Lake Shore Model 455 Gaussmeter User s Manual Use the data entry keys to enter the high setpoint between 350 kG or equivalent depending on selected units Enter the numeric value first Press Enter to accept the new value and advance to the units multiplier Use the A or V key to select a units multiplier of u m blank k or M Press Enter to accept the new selection and return to the normal display Press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display The following example demonstrates the User Defined Range with the setpoints entered above i 0kG Displ Reading 3 5 KG 1 7 KG 0 8 KG 0 8 KG 1 7kG 43 5 kG i ZEN 5V 2 5 V Ce 42 5V AEN H0V The following example is an asymmetrical scaling which demonstrates the versatility of user selectable scaling Dispi 1 5 KG Reading okG 40 5kG 1kG 42kG 2 5KG 43kG Vole HN 5V 2 5 V a 25 V 45V H0V If the Manual mode is selected the manual entry screen appears following the analog mode setting screen
140. erated by the Model 455 to measure the current through the 3 Q resistor 11 Configure the Model 455 excitation current to 100 mA HALLCS 1 CSMODE 2 12 Read the current using the DVM Store as AVGPOSCURRENT 13 Connect the DVM voltage input across the 3 Q resistor 14 Read the voltage using the DVM Store as AVGPOS VOLTAGE 15 Connect the DVM current input in series with the hall current source generated by the Model 455 to measure the current through the 3 Q resistor SOOO el FONE es EN Service 8 11 Lake Shore Model 455 Gaussmeter User s Manual 16 Configure the Model 455 excitation current to 100 mA HALLCS 1 CSMODE 3 17 Read the current using the DVM Store as AVGNEGCURRENT 18 Connect the DVM voltage input across the 3 Q resistor 19 Read the voltage using the DVM Store as AVGNEGVOLTAGE 20 Calculate EXPECTEDRESISTANCE AVGPOSVOLTAGE AVGNEGVOLTAGE AVGPOSCURRENT AVGNEGCURRENT 21 Calculate the Gain Calibration Factor GCF EXPECTEDRESISTANCE ACTUALRESISTANCE Test this factor to be 1 0 42 22 Send the Gain Calibration Factor GCF to the Model 455 CALG 1 5 lt GCF gt 23 Connect the 3 Q resistor across the Gaussmeter input of the Model 455 using a proper 4 lead connection 24 Configure Model 455 for 100 mA excitation current HALLCS 1 normal excitation current mode CSMODE 1 25 Read the resistor using the Model 455 RDGOHM Verify the reading to be EXPECTEDRESISTANCE
141. es information on the accessories and probes available for the Model 455 DSP Gaussmeter 7 1 MODELS The list of Model 455 Model numbers is provided as follows Model Description 455 Standard Model 455 DSP Gaussmeter Power is configured as shown below Power Configurations The instrument is configured at the factory for customer selected power as follows 100 V US cord NEMA 5 15 120 V US cord NEMA 5 15 220 V Euro cord CEE 717 240 V Euro cord CEE 717 240 V UK cord BS 1363 240 V Swiss cord SEV 1011 220 V China cord GB 1002 SD Nn BR QW NtR 7 2 ACCESSORIES Accessories are devices that perform a secondary duty as an aid or refinement to the primary unit A list of accessories available for the Model 455 is as follows Description Of Accessories G 106 253 25 pin D Sub Plug Used for I O mating connector G 106 264 25 pin D Sub Shell Used for I O mating connector TEEE 488 Cable Kit One meter 3 feet long IEEE 488 GPIB computer interface cable assembly Nal Includes extender required to use both IEEE cable and Auxiliary I O connector simultaneously 4060 Standard Zero Gauss Chamber For standard probe offset nulling Size 32 x 32 x61 mm 1 3 x 1 3 x 2 4 in Bore 12 mm diameter x 51 mm deep 0 5 x 2 in See Figure 7 17 4065 Large Zero Gauss Chamber For Gamma Probe offset nulling Size 57 x 53 x 305 mm
142. essage to the bus controller The user program may then direct the bus controller to serial Poll the instruments on the bus to identify which one requested service the one with bit 6 set in its status byte Serial polling will automatically clear RQS of the Status Byte Register This allows subsequent serial polls to monitor bit 6 for an SRQ occurrence generated by other event types After a serial poll the same event or any event that uses the same Status Byte summary bit will not cause another SRQ unless the event register that caused the first SRQ has been cleared typically by a query of the event register The serial poll does not clear MSS The MSS bit stays set until all enabled Status Byte summary bits are cleared typically by a query of the associated event register refer to Section 6 1 4 3 4 The programming example in Table 6 3 initiates an SRQ when a command error is detected by the instrument Remote Operation 6 9 Lake Shore Model 455 Gaussmeter User s Manual Table 6 3 Programming Example to Generate an SRQ Command or Operation Description ESR Read and clear the Standard Event Status Register ESE 32 Enable the Command Error CME bit in the Standard Event Status Register SRE 32 Enable the Event Summary Bit ESB to set the RQS ABC Send improper command to instrument to generate a command error Monitor bus Monitor the bus until the Service Request interrupt SRQ is sent Initiate
143. f On or to follow the Alarm operation Press Enter to accept the new selection and continue If alarm is selected the next setting screen will appear otherwise the instrument will return to the normal display Press Escape to cancel the new selection and return to the normal display If the relay is in alarm mode the next relay setup screen appears as a prompt for an alarm selection Use the A or V key to select low high or both alarms Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 4 22 Operation Lake Shore Model 455 Gaussmeter User s Manual 4 12 ANALOG OUTPUT 3 The Analog Output 3 provides a DC voltage proportional to the displayed field The displayed field reading may be corrected for probe nonlinearity zero offset and temperature This output has an update rate of 30 readings per second By default the instrument is configured so that 3 5 volts will equal full scale for the selected range The DC voltage of Analog Output 3 can be configured so that 10 volts maximum will equal full scale for the selected range The high and low limits can be configured so that lower voltages will equal full scale for the selected range 4 12 1 Analog Output 3 Mode Setting Analog Output 3 may be configured in four different modes of operation The following list gives a description of each mode Off The output of Analog 3
144. figured in Wide Band RMS measurement mode Analog Output is a real time analog signal proportional to the AC magnetic field and scaled to 3 5 volts for full scale of selected range except for the lowest range which is scaled to 0 35 volts for full scale range The output has a frequency range of 1 Hz to 20 kHz If the instrument is configured in Narrow Band RMS measurement mode Analog Output 1 may only be useful as a verification of the Model 455 measurement hardware The signal contains the 5 kHz modulation of the current source making it difficult to use as an accurate field representation Analog Output 2 provides an AC voltage proportional to the AC magnetic field through a high speed D A converter This voltage is corrected for the nominal sensitivity of the probe The output is updated at a rate of 40 000 readings per second The Analog Output 2 is equipped with a two pole analog lowpass filter at 145 kHz The individual D A samples are still visible and the signal may be improved with the addition of external analog filters Operation RMS Operation 4 15 Lake Shore Model 455 Gaussmeter User s Manual 4 8 PEAK MEASUREMENT MODE To measure pulsed or periodic fields press the Peak key on the front panel In Peak measurement mode the keypad and functionality of the Model 455 is optimized to provide the best interaction for Peak measurements The keypad features are described in the following paragraphs NOTE Max Hold is not offered
145. for Peak Measurement Mode 4 8 1 Peak Operation Select Range The Model 455 reads each Lake Shore probe type High Stability High Sensitivity and Ultra High Sensitivity The tables below list full scale ranges for each probe sensitivity along with the display resolution Measurement resolution noise floor varies depending on probe and application High Stability Probe HST Gauss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 350 00 kG 35 000 T 350 00 kOe 28 000 MA m 35 000 kG 3 5000 T 35 000 kOe 2 8000 MA m 3 5000 kG 350 00 mT 3 5000 kOe 280 00 kA m 350 00 G 35 000 mT 350 00 Oe 28 000 kA m 35 000 G 3 5000 mT 35 000 Oe 2 8000 kA m High Sensitivity Probe HSE Gauss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 35 000 kG 3 5000 T 35 000 kOe 2 8000 MA m 3 5000 kG 350 00 mT 3 5000 kOe 280 00 kA m 350 00 G 35 000 mT 350 00 Oe 28 000 kA m 35 000 G 3 5000 mT 35 000 Oe 2 8000 kA m 3 5000 G 350 00 uT 3 5000 Oe 280 00 A m Ultra High Sensitivity Probe UHS Gauss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 35 000 G 3 5000 mT 35 000 Oe 2 8000 kA m 3 5000 G 350 00 uT 3 5000 Oe 280 00 A m 350 00 mG 35
146. for rated accuracy The probe and the zero gauss chamber should be at the same temperature Operation DC Operation 4 7 Lake Shore Model 455 Gaussmeter User s Manual To zero the probe in the zero gauss chamber first allow the temperature of the probe and chamber to equalize A large temperature discrepancy affects the quality of the calibration Carefully place the probe tip into the chamber Orientation of the probe is not critical Once inserted press Zero Probe The following screen appears as a prompt to zero the probe Press Enter to begin the zero probe process Press Escape to cancel the sequence and return to the normal display During the zero probe process the calibration message below will appear Do not move the probe until the zero probe process is complete and the display returns to the normal display If during the zero probe process the measured offset is larger than expected the Model 455 will put up the following message alerting to the user that there may be a problem with the probe The Model 455 will continue to operate with the offset correction but it will be up to the individual to investigate the nature of the offset 4 6 4 DC Operation Max Hold The Max Hold function captures the largest Maximum or smallest Minimum field readings or field magnitudes since the last Reset press To turn the Max Hold feature on press the Max Hold key The following screen will ap
147. ftware Support LabVIEW driver Alarm Settings High low setpoint inside outside and audible Actuators LED annunciator beeper and relays Relays Number 2 Contacts Normally open NO normally closed NC and common C Contact rating 30 VDC at 2 A Operation Follows alarm or operated manually Connector Shared 25 pin I O connector Voltage Output 1 Configuration Real time analog voltage output of wide band AC signal Range 3 5 V Scale 3 5 V full scale on selected range Frequency response 10 Hz to 20 kHz wide band AC Accuracy Probe dependent Noise 1 0 mV RMS Minimum load resistance 1 KQ short circuit protected Connector Shared 25 pin I O connector Voltage Output 2 Configuration Voltage output of field value generated by DAC Range 5 V Scale 3 5 V full scale on selected range Resolution 16 bit 0 15 mV Update rate 40 000 updates s Accuracy 10 mV Noise 0 3 mV RMS Minimum load resistance 1 kQ short circuit protected Connector Shared 25 pin I O connector 1 6 Introduction Lake Shore Model 455 Gaussmeter User s Manual Specifications Continued Voltage Output 3 Configuration Voltage output of compensated DC or RMS field value generated by DAC Range 10 V Scale User specified defaults same as voltage output 2 Resolution 16 bit 0 3 mV Update rate 30 updates s Accuracy 2 5 mV Noise 0 3 mV RMS Minimum load resistance 1 KQ short circuit protected Connector Shared 2
148. ge Remarks This command is used to set the temperature measurement to manual mode so that each range can be calibrated Default is mode 0 autorange CALTEMP Temperature Measurement Setup Query Input CALTEMP term Returned lt mode gt lt range gt term Format n n Refer to command for description 8 16 Service Lake Shore Model 455 Gaussmeter User s Manual CALZ Zero Offset Calibration Constant Command Input CALZ lt type gt lt range gt lt value gt term Format n n znnnnnnn lt type gt Specifies the item to calibrate Valid entries are 1 100 mA hall current source not used 2 10 mA hall current source not used 3 mA hall current source not used 4 Analog Outputs 1 3 5 Temperature lt range gt Specifies the range of the item to calibrate Valid entries are 1 300 uQ range hall current source not used 10 pA range temp Analog Output 1 not used 2 3 MQ range hall current source not used 100 uA range temp Analog Output 2 3 30 MQ range hall current source not used 1 mA range temp Analog Output 3 4 300 mQ range hall current source not used 5 3Q range hall current source not used lt value gt Zero offset calibration constant value Remarks The range variable is ignored but needs to be sent for types that do not need to specify a range types 2 3 and 4 A range value of 1 should be sent for those types The hall current sources do not have
149. h an outer shield The connectors are 24 way Amphenol 57 Series or equivalent with piggyback receptacles to allow daisy chaining in multiple device systems The connectors are secured in the receptacles by two captive locking screws with metric threads The total length of cable allowed in a system is 2 meters for each device on the bus or 20 meters maximum The Model 455 can drive a bus of up to 10 devices A connector extender is required to use the IEEE 488 Interface and the Auxiliary I O connector at the same time Figure 8 7 shows the IEEE 488 Interface connector pin location and signal names as viewed from the Model 455 rear panel 24 IEEE 488 INTERFACE ng zi 9 S gek IEEE_Connector bmp PIN SYMBOL DESCRIPTION 1 DIO 1 Data Input Output Line 1 2 DIO2 Data Input Output Line 2 3 DIO3 Data Input Output Line 3 4 DIO4 Data Input Output Line 4 5 EOI End Or Identify 6 DAV Data Valid 7 NRFD Not Ready For Data 8 NDAC Not Data Accepted 9 IFC Interface Clear 10 SRQ Service Request 11 ATN Attention 12 SHIELD Cable Shield 13 DIO5 Data Input Output Line 5 14 DIO6 Data Input Output Line 6 15 DIO7 Data Input Output Line 7 16 DIO8 Data Input Output Line 8 17 REN Remote Enable 18 GND6 Ground Wire Twisted pair with DAV 19 GND7 Ground Wire Twisted pair with NRFD 20 GND8 Ground Wire Twisted pair with NDAC 21 GND9 Ground Wire Twisted pair with IFC 22 GND
150. hore Model 455 Gaussmeter User s Manual LOCK Front Panel Keyboard Lock Command Input LOCK lt state gt lt code gt term Format n nnn lt state gt 0 Unlocked 1 Locked lt code gt Specifies lock out code Valid entries are 000 999 Remarks Locks out all front panel entries Example LOCK 1 123 term Enables keypad lock and sets the code to 123 LOCK Front Panel Keyboard Lock Query Input LOCK term Returned lt state gt lt code gt term Format nnnn Refer to command for description MXHOLD Max Hold Command Input MXHOLD lt off on gt lt mode gt lt display gt term Format nnn lt off on gt Specifies Max Hold on or off 0 off and 1 on lt mode gt Specifies checking magnitude absolute value used or algebraically includes sign 1 Magnitude check 2 Algebraic check lt display gt Specifies Display configuration when Max Hold is on 1 Display Maximum value on top line 2 Display Minimum value on top line 3 Display Both Max on top line and Minimum on bottom line This overrides the DISPLAY command configuration Example MXHOLD 1 1 2 term Turns the Max Hold feature on using the Magnitude checking mode The Model 455 displays both Max and Min values MXHOLD Max Hold Query Input MODE term Returned lt off on gt lt mode gt lt display gt term Format n n n Refer to command for description MXRST Max Hold Reset Command Input MXRST term Remarks Resets the minimum and ma
151. hotograph any container that has significant damage before opening it If there is visible damage to the contents of the container contact the shipping company and Lake Shore immediately preferably within 5 days of receipt of goods Keep all damaged shipping materials and contents until instructed to either return or discard them Open the shipping container and keep the container and shipping materials until all contents have been accounted for Check off each item on the packing list as it is unpacked Instruments themselves may be shipped as several parts The items included with the Model 455 are listed below Contact Lake Shore immediately if there is a shortage of parts or accessories Lake Shore is not responsible for any missing items if not notified within 60 days of shipment Inspect all items for both visible and hidden damage that occurred during shipment If damage is found contact Lake Shore immediately for instructions on how to file a proper insurance claim Lake Shore products are insured against damage during shipment but a timely claim must be filed before Lake Shore will take further action Procedures vary slightly with shipping companies Keep all shipping materials and damaged contents until instructed to either return or discard them If the instrument must be returned for recalibration replacement or repair a return authorization RA number must be obtained from a factory representative before it is returned The Lake Shore RA
152. ia a 8 2 8 6 ERROR MESSAGES giereg nis aa deed ial and aiiai ae Taneri Eer et 8 3 8 7 ELECTROSTATIC DISCHARGE meala aa eE a Eaa a a eai aa E a aa i aaie 8 4 8 7 1 Identification of Electrostatic Discharge Sensitive Components 8 4 8 7 2 Handling Electrostatic Discharge Sensitive Components sssesseessessessesrresresrreerresre 8 4 8 8 ENCLOSURE TOP REMOVAL AND RER ACEMENT 8 5 8 9 FIRMWARE REPLACEMENT ae a anaa a aaia aaa eae eaaa aaa a a aa e e a a aaia 8 5 8 10 CONNECTOR AND CABLE DEFINITIONS sssseseesseesseesseesressrnssrrssrrsrnssrnssrnssrnssrnssrnssrnssnns 8 7 8 10 1 Serial Interface Cable Witmg 8 9 8 10 2 IEEE 488 INTERFACE Connector esessseesresresrssirssirssirssrissirssrissrnasrisstnsstnnstnnsrnnnrnn te 8 10 8 11 CALIBRATION PROCEDUDE 8 11 8 11 1 Equipment Required for Calibration ccccccceeeeeeseeceeeeeceeeeeeeaeeeeaeeseeeeeseaeeeeaeeeeeeeseeneess 8 11 8 11 2 Gaussmeter Calbratton nenun nn nenn 8 11 8 11 3 Temperature Measurement Calibration ccccceceeeeeeeeeceeeeeceaeeeeaaeeeeeeeseaeeesaaeeeeaaeseeeeeeaas 8 14 8 11 4 Analog Output 2 and 3 Calibration cccecccececeeeesneeeeeeceeeeecaeeeeaaeeeeeeeseaeeeseaeeeeaeseneeeeaas 8 14 8 11 5 Calibration Specific Interface Commande 8 16 A UNITS FOR MAGNETIC PROPERTIES sseccsseeesseeeeseeeeeseeeeeseeessaeeeseeeenseeeseeeseseaesnseeeeneeees A 1 iv Table of Contents Figure No 1 1 2 1 2 2 2 3 2 4 2 5 2 6 2 7 3 1 3 2 3 3 3 4 3 5 3 6 3
153. if available 4 Relative setpoint Example DISPLAY 3 term Probe Temperature will be displayed on Line 2 if the probe is capable of measuring temperature The Frequency will also be displayed if the Model 455 is in RMS mode DISPLAY Display Configuration Query Input DISPLAY term Returned lt item gt term Format n Refer to command for description IEEE TEEE 488 Interface Parameter Command Input IEEE lt terminator gt lt EOI enable gt lt address gt term Format n n nn lt terminator gt Specifies the terminator Valid entries 0 lt CR gt lt LF gt 1 lt LF gt lt CR gt 2 lt LF gt 3 no terminator must have EOI enabled lt EOI enable gt Sets EOI mode 0 enabled disabled lt address gt Specifies the IEEE address 1 30 Address 0 and 31 are reserved Example IEEE 0 0 4 term After receipt of the current terminator the instrument uses EOI mode uses lt CR gt lt LF gt as the new terminator and responds to address 4 IEEE IEEE 488 Interface Parameter Query Input IEEE term Returned lt terminator gt lt EOI enable gt lt address gt term Format n n nn Refer to command for description KEYST Keypad Status Query Input KEYST term Returned lt keypad status gt term Format nn Remarks Returns a number descriptor of the last key pressed since the last KEYST KEYST returns 1 after initial power up Returns a 0 if no key pressed since last query 6 30 Remote Operation Lake S
154. imately 4 seconds It is used to modify less frequently changed setup parameters This operation is described in the individual key paragraphs for the keys that have this available Setting Selection Allows the user to select from a finite list of parameter values During setting selection the gt lt and m keys are used to select a parameter value Enter is used to accept the change and advance to the next parameter Escape will cancel the change to that parameter and return to the normal display Setting selection screens always include the message Select with w Data Entry Allows the user to enter numeric parameter values using the data entry keys that are printed on the key tops Data entry keys include numbers from 0 to 9 sign and decimal point The labels printed above the keys describe the key function during normal operation When one of the keys is pressed and a data entry sequence is started the keys follow the data entry functions printed on the key tops Once the correct parameter value is entered press Enter to accept the change and advance to next parameter Pressing Escape once will clear the new value and restart the setting sequence Pressing Escape again will return to the normal display Data entry screens always include the message Enter for followed by the parameter being set Related setting selection and data entry sequences are often chained together under a single key To skip over a parameter without changi
155. into a 19 inch rack mount cabinet using the optional Lake Shore Model RM Rack Mount Kit or the Model RM2 Dual Rack Mount Shelf The Rack Mount Kit contains mounting ears panel handles and screws that adapt the front panel to fit into a 3 5 inch tall full rack space Refer to Figure 3 7 and Figure 3 8 for installation details Refer to NOTE NOTE Customer must use 5 4 in 2 mm hex key to remove four existing screws from sides of instrument Unit on right side mounting shown Unit on left side also possible Item Description P N Qty 1 Rack mount ear 107 440 1 2 Rackmountsupport 107 442 1 3 Rack mount panel 107 432 1 4 Rackmounthandle 107 051 01 2 5 Screw 6 32x 2in 0 035 4 FHMS Phillips 6 Screw 8 32x3in 0 081 6 FHMS Phillips Figure 3 7 Model RMG Rack Mount Kit P N 4022 3 8 Installation Refer to installation wy procedure ker Lake Shore Model 455 Gaussmeter User s Manual i aay Figure 3 8 Model RM2 Dual Rack Mount Shelf P N 4026 Installation 3 9 Lake Shore Model 455 Gaussmeter User s Manual This Page Intentionally Left Blank 3 10 Installation Lake Shore Model 455 Gaussmeter User s Manual CHAPTER 4 OPERATION 4 0 GENERAL This chapter provides instructions for the general operating features of the Model 455 Gaussmeter Advanced operation including Probe management is in Chapter 5 Computer interface instructions are in Chapter 6
156. ion The Model 455 is calibrated against a set of standard resistors The Model 455 is configured to give readings in ohms The highest range for the 100 mA excitation current is calibrated by measuring the 3 Q standard resistor This resistor is measured by using the HP 3458 to measure the current source of the Model 455 and the voltage across the resistor This configuration is only valid for this range because the accuracy of the HP3458 is unacceptable for the remaining Model 455 ranges Therefore the remaining ranges are calibrated by using the previous calibrated range as shown in the following steps 8 11 2 1 Gaussmeter Calibration 100 mA Excitation Ranges 1 Set the Gain Correction Factor to 1 for all five of the 100 mA hall current source ranges CALG 1 1 1 CALG KZ ex Connect a short across the Gaussmeter input of the Model 455 using a proper 4 lead connection Configure the Model 455 for 100 mA excitation current HALLCS 1 Configure the Model 455 for DC 5 digits RDGMODE 1 3 1 1 1 on the 3 5 Q range RANGE 5 Zero the probe using the Zero Probe key or the ZPROBE command Connect the 3 Q resistor across the Gaussmeter input of the Model 455 using a proper 4 lead connection Configure the Model 455 for 100 mA excitation current HALLCS 1 Read the resistor using the Model 455 RDGOHM Store as ACTUALRESISTANCE Verify the measurement to be 3 00000 Q 10 Connect the DVM current input in series with the hall current source gen
157. ion on the bus SRQ Service Request Tells the bus controller that the Model 455 needs interface service see Section 6 1 4 6 2 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual A Multiline Command asserts a group of signal lines All devices equipped to implement such commands do so simultaneously upon command transmission These commands transmit with the Attention ATN line asserted low The Model 455 recognizes two Multiline commands LLO Local Lockout Prevents the use of instrument front panel controls DCL Device Clear Clears Model 455 interface activity and puts it into a bus idle state Finally Addressed Bus Control Commands are Multiline commands that must include the Model 455 listen address before the instrument responds Only the addressed device responds to these commands The Model 455 recognizes three of the Addressed Bus Control Commands SDC Selective Device Clear The SDC command performs essentially the same function as the DCL command except that only the addressed device responds GTL Go To Local The GTL command is used to remove instruments from the remote mode With some instruments GTL also unlocks front panel controls if they were previously locked out with the LLO command GET Group Execute Trigger The GET command is used to trigger a device to have its operation started either individually or as part of a group of devices SPE Serial Poll Enable and SPD
158. istic of a momentary signal Output 1 serves only as a diagnostic tool in DC and narrow band AC modes because modulation the probe signal prevents a clear view of the field response Analog Output 2 The second voltage output provides a voltage proportional to measured field with the benefits of some signal processing The output is produced by the DSP through a fast D A converter The output signal is updated at 40 kHz giving good response for low to mid frequency fields Signal quality degrades at high frequency because of the sampling rate Probe offset correction and correction for the nominal sensitivity of the probe can be performed on this signal Analog Output 3 The third voltage output provides a voltage proportional to measured field with the most signal processing of the three outputs All probe compensation available to the display readings including temperature compensation can be performed on this output The output is produced by the microprocessor through a high resolution 16 bit D A converter updated at 30 readings per second Relay1 and Relay 2 The Model 455 has two mechanical relays designated Relay 1 and Relay 2 The relays are most commonly associated with the high and low alarms but they can also be controlled manually and used for other purposes Refer to Section 4 11 for more details Installation 3 7 Lake Shore Model 455 Gaussmeter User s Manual 3 7 RACK MOUNTING The Model 455 can be installed
159. its 2 4 digits 3 5 digits lt rms measurement mode gt RMS measurement mode 1 wide band 2 narrow band lt peak mode gt Specifies peak measurement mode periodic 2 pulse lt peak disp gt Specifies display of peak reading 1 positive 2 negative 3 both RDGMODE 1 3 1 1 1 term The Model 455 is configured for DC field measurement DC resolution of 5 digits wide band rms filter mode peak measurement mode is periodic and positive peak readings will be displayed if the measurement mode is changed to peak RDGMODE Measurement Mode Query Input Returned Format RDGMODE term lt mode gt lt dc resolution gt lt rms measurement mode gt lt peak mode gt lt peak disp gt term n n n n n Refer to command for description RDGFRQ Input Returned Format Remarks Frequency Reading Query RDGFRQ term lt frequency gt term tnnn nnnEtnn Returns the frequency reading in Hz The instrument must be in RMS for this to be valid RDGMNMX Minimum and Maximum Reading Query Input RDGMNMX term Returned lt min gt lt max gt term Format nnn nnnE nn nnn nnnE nn Remarks Returns the most recent minimum and maximum field readings RDGOHM Resistance Reading Query Input RDGOHM term Returned hall resistance gt term Format t nnn nnnEtnn Remarks Returns the Hall resistance of the sensor RDGPEAK Peak Reading Query Input RDGPEAK term Returned
160. lay when the relay is in alarm mode 1 Low Alarm 2 High Alarm 3 Both Alarms Example RELAY 1 2 2 term Relay 1 is setup in Alarms mode and activates when the low alarm activates RELAY Relay Parameter Query Input RELAY lt relay number gt term Format n lt relay number gt Specifies which relay to query 1 2 Returned lt mode gt lt alarm type gt term Format n n Refer to command for description Remote Operation 6 35 Lake Shore Model 455 Gaussmeter User s Manual RELAYST Relay Status Query Input RELAYST lt relay number gt term Format n lt relay number gt Specifies which relay to query 1 Relay 1 2 Relay 2 Returned lt status gt term Format n 0 Off 1 On RELSP Relative Setpoint Command Input RELSP lt setpoint gt term Format tnnn nnnEtnn lt setpoint gt Specifies the setpoint to use in the relative calculation 350 kG Example RELSP 1200 term Configure the relative setpoint as 1200 Gauss if units in Gauss The relative reading will use this value if relative is using the user defined setpoint Refer to REL command RELSP Relative Setpoint Query Input RELSP term Returned lt setpoint gt term Format t nnn nnnEtnn Refer to command for description TUNIT Probe Temperature Units Command Input TUNIT lt units gt term Format n lt units gt 1 Celsius 2 Kelvin Example TUNIT 1 term Configures the Model 455 to report probe temperature in C TUNI
161. le when driving a magnet power supply The next analog output setup screen appears as a prompt for configuring the voltage limit Use the A or W key to select from 1 volt through 10 volts Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display Operation 4 25 Lake Shore Model 455 Gaussmeter User s Manual 4 13 LOCKING THE KEYPAD The keypad lock feature prevents accidental changes to parameter values When the keypad is locked all parameter values may be viewed but none may be changed from the front panel A 3 digit code must be used to lock and unlock the keypad The factory default code is 123 and it can only be changed using a computer interface If the instrument parameters are set to default values the code is reset to the factory default The instrument parameters cannot be reset to default values from the front panel when the keypad is locked The following message will appear on the display if the user attempts to change a locked parameter NOTE The computer interface has a remote operation mode that may be mistaken for a locked keypad If the Remote LED annunciator is on press the Local key to regain local control of the instrument To lock the instrument keypad press and hold the Enter key for 5 seconds The following screen appears as a prompt for the 3 digit lock code Use the data
162. le Program A Visual Basic program is included to illustrate the IEEE 488 communication functions of the instrument Refer to Section 6 1 5 1 for instructions on how to setup the program The Visual Basic code is provided in Table 6 5 A description of program operation is provided in Section 6 1 5 3 While the hardware and software required to produce and implement this program is not included with the instrument the concepts illustrated apply to almost any application where these tools are available 6 1 5 1 IEEE 488 Interface Board Installation for Visual Basic Program This procedure works for Plug and Play GPIB Hardware and Software for Windows 98 95 This example uses the AT GPIB TNT GPIB card Install the GPIB Plug and Play Software and Hardware using National Instruments instructions 2 Verify that the following files have been installed to the Windows System folder a gpib 32 dll b gpib dll c gpib32ft dll Files b and c support any 16 bit Windows GPIB applications being used 3 Locate the following files and make note of their location These files will be used during the development process of a Visual Basic program a Niglobal bas b Vbib 32 bas NOTE If the files in Steps 2 and 3 are not installed on your computer they may be copied from your National Instruments setup disks or they may be downloaded from www ni com 4 Configure the GPIB by selecting the System icon in the Windows 98 95 Control Panel located under Settings o
163. lection and return to the normal display Selecting the range this way will disable the Auto Range function To enable the Auto Range function press Autorange The screen appears as a prompt for turning the Auto Range function on or off Use the A or V key to select from Off or On Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display NOTE Autorange should not be used when measuring a small RMS field in the presence of a larger DC background 4 7 2 RMS Measurement Band The Model 455 offers two RMS measurement bands to improve the overall RMS measurement performance The instrument may be configured to use a DC current to excite the Hall sensor Wide Band or an AC current to excite the Hall sensor Narrow Band To configure the RMS Measurement band for the RMS measurement press and hold the RMS key for approximately 4 seconds The RMS band setup screen appears as a prompt for filter band setting Use the A org key to select from Wide or Narrow Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display 4 7 3 RMS Operation Frequency Measurement With certain limitations the Model 455 Gaussmeter is capable of measuring and displaying the frequency of an AC magnetic field The frequency is calculated using a zero crossing cou
164. lection and return to the normal display If the probe does not include temperature compensation this setting is ignored 5 1 4 Extension Cable The complex nature of Hall effect measurements makes it necessary to match extension cables to the probe when longer cables are needed Keeping probes and their extensions from getting mixed up can become a problem when more than one probe is in use The Model 455 alleviates some of the difficulty by allowing users to match probes to extensions in the field Stored information can be viewed on the front panel and read over computer interface to ensure proper mating NOTE Calibrated probe and extension cable pairs may be purchased from Lake Shore and are recommended for the best accuracy Extension cables with no calibration may also be used The Model 455 can then be used to match a probe to the un calibrated extension cable To match a probe with an extension cable verify that the probe is connected to the instrument To begin the matching process press and hold the Probe key for approximately 4 seconds The following screen appears as a prompt for selecting the programming method Use the A or V key to select from MPEC program extension cables or MCBL Program User programmable cables refer to Section 5 2 1 Press Enter to accept the new selection and continue the matching process Press Escape to cancel the selection and return to the normal display The next probe matching screen
165. ll appear for approximately 6 seconds Where XXXXXXXXXX is the serial number of the attached probe up to 10 digits in length 5 1 3 Field and Temperature Compensation NOTE Unless there is a specific reason Lake Shore strongly advises customers got to turn field and temperature compensation off it may reduce reading accuracy substantially To improve accuracy all Lake Shore probes have a magnetic field compensation table stored in a PROM Turning Field Compensation OFF causes the Model 455 to ignore this table and calculate the field based on a nominal probe sensitivity Advanced Operation 5 1 Lake Shore Model 455 Gaussmeter User s Manual Some probes also feature temperature compensation Turning Temperature Compensation OFF causes the Model 455 to ignore this data To configure the Field Compensation setting press the Probe key and wait until the Probe Serial number display disappears and the following screen appears as a prompt for field compensation Use the A or V key to select Off or On Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the selection and return to the normal display The next probe setting screen appears as a prompt for changing the temperature compensation setting Use the A or V key to select Off or On Press Enter to accept the new selection and return to the normal display Press Escape to cancel the se
166. measurement mode press and hold the Max Hold key for approximately 4 seconds The max hold setup screen appears as a prompt for selecting the measurement mode Use the A or W key to select Magnitude or Algebraic Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display Operation DC Operation 4 9 Lake Shore Model 455 Gaussmeter User s Manual 4 6 4 2 Max Min Display Setting Typically the maximum reading Max is displayed on the top line when the Max Hold feature is on Sometimes it may be beneficial to display the minimum reading Min on the top line instead of the maximum The user may also display both the maximum and minimum readings with the maximum reading on the top line and the minimum reading on the bottom line Displaying both will override the two line display configuration when Max Hold is active refer to Section 4 4 1 To configure the Max Hold display setting continue from the Max Hold mode screen or press and hold Max Hold and then press Enter until the following screen appears as a prompt for Max Hold display setup Use the A or W key to select Max Min or Both Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 4 6 5 DC Operation Reset If the Max Hold function is on and the Reset key is pre
167. n Lake Shore Model 455 Gaussmeter User s Manual Message Strings Continued A query string is issued by the computer and instructs the instrument to send a response The query format is lt query mnemonic gt lt gt lt space gt lt parameter data gt lt terminators gt Query mnemonics are often the same as commands with the addition of a question mark Parameter data is often unnecessary when sending queries Query mnemonics and parameter data if necessary is described in Section 6 3 Terminators must be sent with every message string The computer should expect a response very soon after a query is sent A response string is the instruments response or answer to a query string The instrument will respond only to the last query it receives The response can be a reading value status report or the present value of a parameter Response data formats are listed along with the associated queries in Section 6 3 The response is sent as soon as possible after the instrument receives the query Typically it takes 10 ms for the instrument to begin the response Some responses take longer 6 2 6 Message Flow Control It is important to remember that the user program is in charge of the serial communication at all times The instrument can not initiate communication determine which device should be transmitting at a given time or guarantee timing between messages All of this is the responsibility of the user program When issuing commands
168. n the Start Menu Configure the GPIB Settings as shown in Figure 6 5 Configure the DEV12 Device Template as shown in Figure 6 6 Be sure to check the Readdress box Remote Operation 6 11 Lake Shore Model 455 Gaussmeter User s Manual System Properties zl General Device Manager Hardware Profiles ee GPIB TNT Plug and Play Properties L2 1x p General GPIB Settings Resources View devices by type View devices by eo Computer KR AT GPIB TNT Plug and Play CDROM zi Disk drives ISA PnP Serial Number O04D7F40 o BR Display adapters Floppy disk controllers Interface Name r Termination Methods SN Hard disk controllers arieo 7 E Send EOI at end of Write z Keyboard Monitor MV Terminate Read on EOS H A Mouse 7 i National Instruments GPIB Interfaces kV Set EO with EOS on Write AT GPIB TNT Plug and Play E Bb EOS Compare o B Network adapters Secondary zo WM Ports COM amp LPT fio EQS Byte i NONE x BR System devices 140 Timeout 5 10sec e Properties Refresh Remove IV System Controller Figure 6 5 GPIBO Setting Configuration System Properties General Device Manager Hardware Profiles Performance View devices by type Wutz National Instruments GPIB Interfaces Properties 27 x General Device Templates m Computer CDROM
169. necessarily be plugged together without interface setup The remainder of this paragraph briefly describes the key features of a serial interface that are supported by the instrument A customer supplied computer with similarly configured interface port is required to enable communication 6 2 1 Changing Baud Rate To select the Serial Interface Baud Rate press the Interface key The first computer interface screen appears as a prompt for Baud Use the A or V key to select 9600 19200 38400 or 57600 Baud The default is 9600 Baud Press Enter to accept the new Selection and continue to the next setting screen Press Escape to cancel the new selection and return to the normal display 6 2 2 Physical Connection The Model 455 has a 9 pin D Subminiature plug on the rear panel for serial communication The original RS 232C standard specifies 25 pins but both 9 and 25 pin connectors are commonly used in the computer industry Many third party cables exist for connecting the instrument to computers with either 9 or 25 pin connectors Section 8 11 1 gives the most common pin assignments for 9 and 25 pin connectors Please note that not all pins or functions are supported by the Model 455 The instrument serial connector is the plug half of a mating pair and must be matched with a socket on the cable Ifa cable has the correct wiring configuration but also has a plug end a gender changer can be used to mate two plug ends together
170. net Axial Reference Magnet Axial Reference Magnet Axial Reference Magnet Axial Reference Magnet Axial Reference Magnet Transverse Reference M Transverse Reference M Transverse Reference M Transverse Reference M Transverse Reference M Transverse Reference M Transverse Reference M Transverse Reference M 0 312 inch inside diameter 100 G 1 0 312 inch inside diameter 200 G 1 0 312 inch inside diameter 300 G 1 0 312 inch inside diameter 500 G 1 0 312 inch inside diameter 1 kG 1 0 312 inch inside diameter 2 kG 1 agnet 0 062 inch gap 200 G 1 agnet 0 062 inch gap 500 G 1 agnet 0 062 inch gap 1 kG 0 5 agnet 0 062 inch gap 2 kG 0 5 agnet 0 062 inch gap 5 kG 0 5 agnet 0 062 inch gap 10 kG 5 agnet 0 343 inch gap 50 G 1 agnet 0 343 inch gap 100 G 1 Probes and Accessories 71 9 Lake Shore Model 455 Gaussmeter User s Manual 7 5 HALL GENERATOR Lake Shore sells a series of bare Hall generators for applications that are unsuitable for standard probe configurations This section describes the handling wiring and specifications of the bare Hall generators available from Lake Shore Please consult the factory for availability of bare Hall generator types not detailed in this section 7 5 1 Hall Generator Handling CAUTION Care must be exercised when handling the Hall generator The device is very fragile Stressing the Hall sensor can alter its output Any excess force can
171. ng Earth s local magnetic field Users wishing to cancel out large magnetic fields should use the Relative function Refer to Section 4 6 6 Probe temperature can also affect readings Refer to the two separate temperature coefficients listed on the specification sheet The High Stability HST probes exhibit a low temperature coefficient of gain due to the inherent thermal stability of the materials used in their construction Probe readings are dependent on the angle of the sensor Hall sensor in relation to the magnetic field Maximum output occurs when the flux vector is perpendicular to the plane of the sensor This is the condition that exists during factory calibration The greater the deviation from orthogonality from right angles in either of three axes the larger the error of the reading For example a 5 variance on any one axis causes a 0 4 error a 10 misalignment induces a 1 5 error etc See Figure 7 1 Tolerance of instrument probe and magnet must be considered for making critical measurements The accuracy of the gaussmeter reading is typically 0 05 of reading and 0 005 of range but the absolute accuracy readings for gaussmeters and Hall probes is a difficult specification to give because all the variables of the measurement are difficult to reproduce Differences in alignment and positioning will degrade measurement accuracy and repeatability Finally the best probes have an accuracy of 0 10 This implies that the a
172. ng its value press Enter before pressing an arrow or number key To return to the normal display in the middle of a setting sequence press Escape before pressing an arrow or number key Changes entered before Escape is pressed are kept 4 4 DISPLAY SETUP In normal operation the two row by twenty character vacuum fluorescent display provides magnetic readings on the top row and special information or readings on the bottom row The user may configure the bottom row of the display 4 4 1 Two Line Display Configuration The Model 455 can be configured to display different values on the bottom line of the display The following list gives a description of each setting Blank No Bottom line display Field Display the present field reading This is useful if the top line is used for Max Hold Temp Freq Display the probe temperature if available and display the frequency if in RMS Relative SP Display the relative setpoint To configure the display press Display The display configuration screen appears as a prompt for the data to display on the bottom line Use the A or V key to select one of the display items Blank Field Temp Freq or Relative SP Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 4 4 Operation Lake Shore Model 455 Gaussmeter User s Manual 4 4 2 Display Brightness To change the brightness press
173. ng screen Press Escape to cancel the new selection and return to the normal display 4 8 3 Peak Operation Display Setting Typically the positive peak reading PK is displayed on the top line when in Peak measurement mode Sometimes it may be beneficial to display the negative peak reading PK on the top line instead of the maximum The user may also display both peak readings with the positive reading on the top line and the negative reading on the bottom line Displaying both will override the two line display configuration when Peak is active refer to Section 4 4 1 To configure the Peak display setting continue from the Periodic Pulse selection screen or press and hold Peak and then press Enter until the following screen appears as a prompt for Peak display setup Use the A or W key to select PK PK or Both Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 4 8 4 Peak Operation Reset In Peak Measurement mode the Reset key is used to clear any captured pulsed readings 4 8 5 Peak Operation Frequency Measurement In Peak measurement the frequency is only measurable in Periodic mode The frequency is calculated using a zero crossing counter The frequency measurement is only valid for robust fields with a single dominant frequency Refer to Section 4 4 1 to configure the display for frequency Operation Peak Opera
174. ngs and give results of other features such as max min or relative The display can also be configured to show probe temperature or frequency When setting instrument parameters the display gives the operator meaningful prompts and feedback to simplify operation The operator can also control display brightness Following are three examples of the various display configurations The display configured to show the RMS field value and frequency and the probe temperature The display configured to show both the Maximum and Minimum DC field values The display configured to simultaneously show the positive and negative Peak readings Keypad The instrument has a 22 position keypad with individual keys assigned to frequently used features Menus are reserved for less frequently used setup operations The keypad can be locked out to prevent unintended changes of instrument setup Alarm and Relay High and low alarms are included in the instrument Alarm actuators include display annunciator audible beeper and two relays The relays can also be controlled manually for other system needs Voltage Output 1 The first voltage output gives access to amplified voltage signal directly from the probe This voltage is corrected for the nominal sensitivity of the probe and provides the widest bandwidth of the three voltage outputs In wide band AC mode the signal can be viewed on an oscilloscope to observe the shape of AC fields In peak mode the o
175. nt A 2 3 2 1 7 Peak Measuremment ccecccccecesseceeeeseneeseeeeneeeeeeeeeeseeeeeeeseeeeeeeesaaenseseeaaeeeseeaeeeseeseneeeeesenaees 2 3 2 2 FLUX DENSITY OVERVIEW viseti iira a aa aa aa a a Ea aana e KaG EREE 2 4 2 2 1 What ISsFlux Density eegne deni Dea sanceedeccbhes biden red ania Area snets edi tease dine KEES 2 4 2 2 2 How Flux Density B Differs from Magnetic Field Strength H 2 4 2 3 HALE MEASUREMENT vecezeccsscsciedletarecz dense eet ca poda aienea iaai ae aeiia deed 2 4 2 3 1 Lee EE 2 5 2 3 2 Sei EE 2 6 2 3 3 OMS MALO My ent Meteo teen e gege Bereet egene gg 2 6 3 INSTAL AT LOIN ee 3 1 3 0 GENERAL eeigenet weet sitet E E tege tier etal iin acter eee TE 3 1 3 1 INSPECTION AND UNPACKING a ietan aeaaee aa ennan iaa anaa a re aa Aaaa a an aa aaa ae Aat aei aaa 3 1 3 2 REAR PANEL DEFINITION Teesra aaa ea EE aaa e a iaaea 3 2 3 3 LINE INPUT ASSEMBLY a reese aaa a aa nee init e aaa 3 3 3 3 1 Hne V OAC EE 3 3 3 3 2 Line Fuse and Fuse Holder serorea ie Atha S E a en eG 3 3 3 3 3 Power Cord EE 3 3 3 3 4 ONEI e A A AEE EE 3 3 3 4 PROBEINPUT CONNECTION arina a ee e raea aaa raa aaia Erau a AAE dE dE Ea 3 4 3 5 PROBE HANDLING AND OPERATION cae eeeeaeseeeeeseaeeesaeeeeeeseeeeess 3 4 3 5 1 Probe Handing EE 3 4 3 5 2 Probe Operation vii settee ns Gah kali EUREN dee 3 5 3 5 3 Probe Accuracy Considerations ccccccsceceeeeeeeeeeeeeaeeeeeeeseeeecaaeeesaaeseeeeeseaeeesaeeteeeseeeees 3 6 3 6 AUXILIARY 1 0 CONNECTION 3 7 3 7 RACK MOU
176. nt reads parameters from probe memory and the probe is ready to use A new probe can be connected at any time even while the instrument is turned on No parameters need to be entered into the Model 455 for a Lake Shore probe However the Zero Probe function should be performed the first time a probe is used with the instrument and periodically during use If the instrument is powered up with no probe attached the following message is displayed 3 5 PROBE HANDLING AND OPERATION To avoid damage and for best results during use the probes have a number of handling and accuracy requirements that must be observed 3 5 1 Probe Handling Although every attempt has been made to make the probes as sturdy as possible they are still fragile This is especially true for the exposed sensor tip of some transverse probes Care should be taken during measurements that no pressure is placed on the tip of the probe The probe should only be held in place by securing at the handle The probe stem should never have force applied Any strain on the sensor may alter the probe calibration and excessive force may destroy the Hall generator CAUTION Care must be exercised when handling the probe The tip of the probe is very fragile Stressing the Hall sensor can alter its calibration Any excess force can easily break the sensor Broken sensors are not repairable Avoid repeated flexing of the stem of a flexible probe As a rule the stem should n
177. ntage of Full Scale Test this factor to be between 1 and 1 Record this value 12 Send the Offset Correction Factor OCF to the Model 455 CALZ 4 2 lt OCF gt ln Ee eh co are E 8 14 Service 13 14 15 16 17 18 19 Lake Shore Model 455 Gaussmeter User s Manual Configure Analog Output 2 to manual mode 50 MOUT 1 50 Read the voltage using the DVM Verify the reading to be 2 5 VDC 1 mV Record the reading Configure Analog Output 2 to manual mode 50 MOUT 1 50 Read the voltage using the DVM Verify the reading to be 2 5 VDC 1 mV Record the reading Configure Analog Output 2 to manual mode 0 MOUT 1 0 Read the voltage using the DVM Verify the reading to be 0 VDC 1 mV Record the reading Send the CALSAVE command to save the calibration constants into non volatile memory 8 11 4 1 Analog Output 3 Calibration 1 BON ON Rs Se ze 10 11 12 13 14 15 16 17 18 19 Set Analog Output 3 Gain Correction Factor to 1 CALG 4 3 1 and Offset Correction Factor to 0 CALZ 4 3 0 Connect the DVM to Analog Output 3 Configure Analog Output 3 to manual mode 100 ANALOG 3 2 0 0 100 10 Read the voltage using the DVM Record as VMIN Configure Analog Output 3 to manual mode 100 ANALOG 3 2 0 0 100 10 Read the voltage using the DVM Record as VMAX Calculate the Gain Correction Factor GCF 20 VMAX VMIN Note Gain is calculated over the full span of the
178. nter so the indicated value is only valid for robust fields with a single dominant frequency Because of sampling rate limitations the reading is correct only up to 20 kHz Refer to Section 4 4 1 to configure the display to indicate frequency 4 7 4 RMS Operation Reading Rate In RMS measurement mode the reading update rate is 30 readings per second only available over the computer interface The display will update at 5 readings per second independent of the filter setting Operation RMS Operation 4 13 Lake Shore Model 455 Gaussmeter User s Manual 4 7 5 RMS Operation Max Hold The Max Hold function captures the largest Maximum or smallest Minimum RMS field readings since the last Reset press To turn the Max Hold feature on press the Max Hold key The following screen will appear for approximately 3 seconds To turn the Max Hold feature off press the Max Hold key again 4 7 5 1 Max Min Display Setting Typically the maximum reading Max is displayed on the top line when the Max Hold feature is on Sometimes it may be beneficial to display the minimum reading Min on the top line instead of the maximum The user may also display both the maximum and minimum readings with the maximum reading on the top line and the minimum reading on the bottom line Displaying both will override the two line display configuration when Max Hold is active refer to Section 4 4 1 To configure the Max Hold display setting
179. nterface Commands A summary of all the commands is provided in Table 6 9 All the commands are detailed in Section 6 3 1 presented in alphabetical order Sample Command Format IEEE IEEE 488 Interface Parameter Command Input IEEE lt terminator gt lt EO enable gt lt address gt term Format n n nn lt terminator gt Specifies the terminator Valid entries 0 lt CR gt lt LF gt 1 lt LF gt lt CR gt 2 lt LF gt 3 no terminator must have EOI enabled lt EOl enable gt Sets EOI mode 0 enabled 1 disabled lt address gt Specifies the IEEE address 1 30 Address 0 and 31 are reserved Example IEEE 0 0 4 term After receipt of the current terminator the instrument uses EOI mode uses lt CR gt lt LF gt as the new terminator and responds to address 4 Sample Query Format IEEE IEEE 488 Interface Parameter Query Input IEEE term Returned lt terminator gt lt EOI enable gt lt address gt term Format n n nn Refer to command for description Key Begins common interface command ui Required to identify queries aa String of alpha numeric characters t nnn nnnEtnn Number represented in scientific notation format term Terminator characters Sa Indicated a parameter field many are command specific lt state gt Parameter field with only On Off states NOTE Any number being represented in scientific notation may also be entered as a string of number characters The
180. nters or leaves the magnet 4 7 cm dia k 1 845 0 32 dia min working space Transverse 0 062 gap MRT 062 200 within 1 of nominal value MRT 062 500 within 1 of nominal value Axial 0 312 diameter working space MRT 062 1K within 0 5 of nominal value MRA 312 2K within 1 of nominal value MRT 062 2K within 0 5 of nominal value MRA 312 1K within 1 of nominal value MRT 062 5K within 0 5 of nominal value 3 96cm 1 56 O D 0 79 cm 0 31 dia min sd working space 5 dia f entry hole gt _ Axial 0 312 diameter working space Center line of magnet MRA 312 100 within 1 of nominal value is center of gap MRA 312 200 within 1 of nominal value Transverse 0 062 gap MRA 312 500 within 1 of nominal value MRT 062 10K within 0 5 of nominal value Reference_Magnets bmp Figure 7 16 Lake Shore Reference Magnets Probes and Accessories 7 17 Lake Shore Model 455 Gaussmeter User s Manual 7 8 ZERO GAUSS CHAMBER NOTE Use care to ensure the Zero Gauss Chamber does not become magnetized Using a magnetized chamber to zero a probe can lead to erroneous field readings It is a good practice to periodically degauss the chamber If no professional degausser is available a bulk tape degausser Verity VS250 Data Devices PF211 or equivalent may be used Frou ty E y She View SCH 12 2 mm 04 inj diameter by 50 8 mm Ct in deep bore Lut CU WAU CC L
181. nugly on all sides of the instrument in a sturdy corrugated cardboard box The RGA number should be included in the mailing label or written prominently on the outside of the box A copy of the customer contact information and RGA number should be included inside the box Consult Lake Shore with questions regarding shipping and packing instructions Service 8 1 Lake Shore Model 455 Gaussmeter User s Manual 8 3 FUSE DRAWER The fuse drawer supplied with the Model 455 holds the instrument line fuses and line voltage selection module The drawer holds two 5 x 20 mm time delay fuses It requires two good fuses of the same rating to operate safely Fuse ratings are different for different line voltages Refer to Section 8 5 for details Fase Fase G F moit view Ske ve Rear WEN European Dual Fuse Configuration EU_Fuse eps Figure 8 1 Fuse Drawer 8 4 LINE VOLTAGE SELECTION Use the following procedure to change the instrument line voltage selector Verify the fuse value whenever line voltage is changed WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power before performing this procedure Identify the line input assembly on the instrument rear panel See Figure 8 2 Turn the line power switch OFF 0 Remove the instrument power cord With a small screwdriver release the drawer holding the line voltage selector and fuse Slide out the removable plastic fuse holder from the drawer
182. o distinct methods The OPC command is used in conjunction with bit 0 OPC of the Standard Event Status Register If OPC is sent as the last command in a command sequence bit 0 will be set when the instrument completes the operation that was initiated by the command sequence Additional commands may be sent between the instrument and the bus controller while waiting for the initial pending operation to complete A typical use of this function would be to enable the OPC bit to generate an SRQ and include the OPC command when programming the instrument The bus controller could then be instructed to look for an SRQ allowing additional communication with the instrument while the initial process executes The OPC query has no interaction with bit 0 OPC of the Standard Event Status Register If the OPC query is sent at the end of a command sequence the bus will be held until the instrument completes the operation that was initiated by the command sequence Additional commands except RST should not be sent until the operation is complete as erratic operation will occur Once the sequence is complete a 1 will be placed in the output buffer This function is typically used to signal a completed operation without monitoring the SRQ It is also used when it is important to prevent any additional communication on the bus during a pending operation 6 10 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual 6 1 5 IEEE Interface Examp
183. o the confusion in the SI system permeability of air is not 1 so B is not equal to H even in air 2 3 HALL MEASUREMENT The Hall effect was discovered by E H Hall in 1879 For nearly 70 years it remained a laboratory curiosity Finally development of semiconductors brought Hall generators into the realm of the practical A Hall generator is a solid state sensor that provides an output voltage proportional to magnetic flux density As implied by its name this device relies on the Hall effect The Hall effect is the development of a voltage across a sheet of conductor when current is flowing and the conductor is placed in a magnetic field See Figure 2 6 Electrons the majority carrier most often used in practice drift in the conductor when under the influence of an external driving electric field When exposed to a magnetic field these moving charged particles experience a force perpendicular to both the velocity and magnetic field vectors This force causes the charging of the edges of the conductor one side positive with respect to the other This edge charging sets up an electric field which exerts a force on the moving electrons equal and opposite to that caused by the magnetic field related Lorentz force The voltage potential across the width of the conductor is called the Hall voltage This Hall voltage can be utilized in practice by attaching two electrical contacts to the sides of the conductor The Hall voltage can be given by
184. olarity If the control current enters the red lead with I connected to the positive terminal of the current supply and the magnetic field direction B is as shown in Figure 2 6 a positive Hall voltage will be generated at the V lead Reversing either the current or the magnetic field will reverse the output voltage 2 3 3 Orientation Hall generators come in two main configurations axial and transverse Transverse devices are generally thin and rectangular in shape They are applied successfully in magnetic circuit gaps surface measurements and general open field measurements Axial sensors are mostly cylindrical in shape Their applications include ring magnet center bore measurements solenoids surface field detection and general field sensing Figure 2 7 shows these two orientations E C 455 C 2 eps Figure 2 7 Axial and Transverse Configurations 2 6 Background Lake Shore Model 455 Gaussmeter User s Manual CHAPTER 3 INSTALLATION 3 0 GENERAL This chapter provides general installation instructions for the Model 455 gaussmeter Please read this entire chapter before installing the instrument and powering it on to ensure the best possible performance and maintain operator safety For instrument operating instructions refer to Chapter 4 and Chapter 5 For computer interface installation and operation refer to Chapter 6 3 1 INSPECTION AND UNPACKING Inspect shipping containers for external damage before opening them P
185. only the user program should e Properly format and transmit the command including terminators as one string e Guarantee that no other communication is started for 50 ms after the last character is transmitted e Not initiate communication more than 20 times per second When issuing queries or queries and commands together the user program should e Properly format and transmit the query including terminators as one string e Prepare to receive a response immediately e Receive the entire response from the instrument including the terminators e Guarantee that no other communication is started during the response or for 50 ms after it completes e Not initiate communication more than 20 times per second Failure to follow these simple rules will result in inability to establish communication with the instrument or intermittent failures in communication 6 2 7 Serial Interface Example Program A Visual Basic program is included to illustrate the serial communication functions of the instrument Refer to Section 6 2 7 1 for instructions on how to setup the program The Visual Basic code is provided in Table 6 8 A description of program operation is provided in Section 6 2 7 2 While the hardware and software required to produce and implement this program is not included with the instrument the concepts illustrated apply to almost any application where these tools are available Remote Operation 6 19 6 2 7 1 Lake Shore Model 455 G
186. ot be bent more than 45 from the base See Figure 3 3 Force should never be applied to the tip of the probe On all probes do not pinch or allow cables to be struck by any heavy or sharp objects Although damaged or severed cables should be returned to Lake Shore for repair please understand that probes are not always repairable When probes are installed on the gaussmeter but not in use the protective tubes provided with many probes should be placed over the probe handle and stem in order to protect the tip When the gaussmeter is not in use the probes should be stored separately in some type of rigid container The cardboard and foam container that Lake Shore probes are shipped in may be retained for probe storage For further details on available accessories and probes refer to Chapter 7 3 4 Installation Lake Shore Model 455 Gaussmeter User s Manual Do not bend from tip of probe VN Stem 45 Lakeshore Flexible transverse probe The tipis maximum bend angle VERY FRAGILE Figure 3 3 Maximum Flexible Probe Bend Radius 3 5 2 Probe Operation In the DC mode of operation the orientation of the probe affects the polarity reading of the gaussmeter On a transverse probe the Lake Shore name printed on the handle indicates the side for positive flux entry On an axial probe positive flux entry is always from the front of the probe See Figure 3 4 NOTE For best results the instrument and probe should warm
187. otronics Inc Instrument Service Department 575 McCorkle Blvd Westerville OH USA 43082 8888 Mailing Address sales lakeshore com Sales E mail Address i service lakeshore com Instrument Service Telephone 614 891 2244 Sales RER 614 891 2243 ext 131 Instrument Service Fax 614 818 1600 Sales Ge 614 818 1609 Instrument Service When contacting Lake Shore please provide your name and complete contact information including e mail address if possible It is often helpful to include the instrument model number and serial number located on the rear panel of the instrument as well as the firmware revision information as described in Section 4 14 8 2 RETURNING PRODUCTS TO LAKE SHORE If it is necessary to return the Model 455 or accessories for recalibration repair or replacement a Return Goods Authorization RGA number must be obtained from a factory representative or from the Lake Shore web site Do not return a product to Lake Shore without an RGA number The following information must be provided to Lake Shore in order to obtain an RGA number 1 Instrument model and serial number 2 User name company address phone number and e mail address 3 Malfunction symptoms 4 Description of the system in which the product is used If possible the original packing material should be retained for reshipment If not available a minimum of three inches of shock adsorbent packing material should be placed s
188. pear for approximately 3 seconds To turn the Max Hold feature off press the Max Hold key again 4 6 4 1 Magnitude or Algebraic The Max Hold function can be configured to use the magnitude of the field reading only or to include the sign and treat the readings algebraically In Magnitude mode the maximum reading is the field measurement with the largest magnitude independent of sign since the last reset 4 8 DC Operation Operation Lake Shore Model 455 Gaussmeter User s Manual Example If the present maximum reading is 20 kG and the instrument measures 35 kG the 35 kG becomes the new maximum reading If the minimum reading is 3 0 kG and the instrument measures 1 5 kG the 1 5 kG becomes the new minimum reading mmmH 35 kG 3 kG 1 5 kG 0 kG 20 kG 30 kG New Max Original Min New Min Original Max Example of operation Magnitude In Algebraic mode the field values are compared mathematically with the sign included The maximum reading is the larger signed value since the last reset Example If the present maximum reading is 30 kG and the instrument measures 10 kG the 10 kG becomes the new maximum reading If the minimum reading is 3 0 kG and the instrument measures 15 kG the 15 kG becomes the new minimum reading 30 kG 15 kG 0 kG 3 kG 10 kG 30 kG Original Max New Min Original Min New Max Example of operation Algebraic To configure the Max Hold
189. pecifications E 6 18 6 7 Serial Interface Program Control Properties AAA 6 21 6 8 Visual Basic Serial Interface Program 6 22 6 9 GOMMANG SUMMARY EE 6 25 7 1 Cryogenic Hall Generator Specifications 22 eee cecceeeeeeeeeeeeeeeeteneeeeeeeseaeeeeaeeseaeeseaeessaeeeeaeeseeeeeeeseneeseneeseaees 7 12 7 2 Axial Hall Generator Specifications ceeeecceceeeeeeeeeeneeeeeeeeeeeeeaeeeeaeeeeaeeseaeeeeaaeesaeesaeeeseeeseeeseeeesieeseneeenaees 7 13 7 3 Transverse Hall Generator Specifications c ceecceeeceeeeceeeeeeeeneeeseeeeeeeeseeeeseeeseeeesseeeseeeseeesieeeeieeeeneeeeaees 7 14 A 1 WE eltren e Ee RRE TEE A 1 A 2 Recommended SI Values for Physical Constants eeseeseeseeeteeeteeittitsttesttnttnntintttnttnttnntenntnnstnneenntnnnna A 2 vi Table of Contents Lake Shore Model 455 Gaussmeter User s Manual CHAPTER 1 INTRODUCTION 1 0 GENERAL This chapter provides an introduction to the Model 455 DSP Gaussmeter The Model 455 was designed and manufactured in the United States of America by Lake Shore Cryotronics Inc The Model 455 includes the following e Field ranges from 35 mG to 350 kG s DC resolution to 0 02 mG e Basic DC accuracy of 0 075 e DC to 20 kHz AC frequency response e AC narrow and wide band modes e Wide range of standard and custom Hall probes available e Standard Hall probe included 1 1 DESCRIPTION The Model 455 digital signal processing DSP gaussmeter combines the technical advantages of DSP technology with
190. pelled commands and queries are ignored Commands and queries should have a space separating the command and associated parameters s Leading zeros and zeros following a decimal point are not needed in a command string but are sent in response to a query A leading is not required but a leading is required 6 2 8 Troubleshooting New Installation 1 Check instrument Baud rate 2 Make sure transmit TD signal line from the instrument is routed to receive RD on the computer and vice versa Use a null modem adapter if not Always send terminators Send entire message string at one time including terminators Many terminal emulation programs do not Send only one simple command at a time until communication is established ON i ea Be sure to spell commands correctly and use proper syntax Old Installation No Longer Working 7 Power instrument off then on again to see if it is a soft failure 8 Power computer off then on again to see if communication port is locked up 9 Verify that Baud rate has not been changed on the instrument during a memory reset 10 Check all cable connections Intermittent Lockups 11 Check cable connections and length 12 Increase delay between all commands to 100 ms to make sure instrument is not being over loaded Remote Operation 6 23 Lake Shore Model 455 Gaussmeter User s Manual 6 3 COMMAND SUMMARY This paragraph provides a listing of the IEEE 488 and Serial I
191. r s Manual Goes Race EME 2 1 0 sit Register H EH i Decimal OPST G OVLD NPRB Name Operation ests Bit meei Decimal OPSTR uses c t usea u OPSTR reads and clears the register To Operation Event Summary Bit OSB of Operation Event z e s5 4 3 2 1 o0 st Status Byte Register Enable Register zes az iere jatz tit Decimal See Figure 6 2 OPSTE OPSTE Not Not Not la RMINRDG OVLD NPRB Name Used Used Used Figure 6 3 Operation Event Register Figure_6 3 bmp 6 1 4 3 Status Byte and Service Request SRQ As shown in Figure 6 1 the Status Byte Register receives the summary bits from the two status register sets and the message available summary bit from the output buffer The status byte is used to generate a service request SRQ The selection of summary bits that will generate an SRQ is controlled by the Service Request Enable Register 6 1 4 3 1 Status Byte Register The summary messages from the event registers and output buffer set or clear the summary bits of the Status Byte Register see Figure 6 4 These summary bits are not latched Clearing an event register will clear the corresponding summary bit in the Status Byte Register Reading all messages in the output buffer including any pending queries will clear the message available bit The bits of the Status Byte Register are described as follows Operation Summary OSB Bit 7 Set summary bit indicates
192. ra High Sensitivity UHS Low magnitude large volume fields are most effectively measured with ultra high sensitivity probes that have unbeatable low field resolution to 20 uG 2 nT UHS probes or gamma probes are ideal for measuring fringe fields or variations in Earth s magnetic field They should never be used in fields over 30 G UHS probes are larger than other probes and they have a very large active area making them impractical for small volume fields or tight spaces Orientation Getting to the field is often much of the challenge in selecting a probe Field orientation dictates the most basic probe geometry choice of transverse verses axial Other variations are also available for less common more challenging applications Listed below are the standard configurations for HSE and HST probes USH probes require special packaging that is not described here Transverse Transverse probes most often rectangular in shape measure fields normal to their stem width They are useful for most general purpose field measurements and are essential for work in magnet gaps Several stem lengths and thicknesses are available as standard probes Axial Axial probes most often round measure fields normal to their end They can also be used for general purpose measurements but are most commonly used to measure fields produced by solenoids Several stem lengths and diameters are available as standard probes Flexible Flexible probes are special becau
193. rator purchased from Lake Shore will come with a nominal field sensitivity value However we recommend that the customer always check accuracy against a reference field rather than use the sensitivity value sent with the bare Hall generator Because Lake Shore has no control of the conditions beyond the cable the customer must accept responsibility for accuracy and compatibility In cryogenic applications Manganin lead wire is frequently used because of its thermal conductivity properties Manganin wire is not usually acceptable for connection to a Hall generator because the resistance of Manganin wire is often too high The gaussmeter current source is limited in compliance voltage The Model 455 should not drive a load Hall generator wires in cryostat and probe cable greater than 50 Q In fact for best performance the load should be less than 30 Q In cryogenic applications Hall generators are normally connected using twisted pairs of copper wire such as 34 gauge Teflon insulated 7 10 Probes and Accessories Lake Shore Model 455 Gaussmeter User s Manual 7 5 4 Attachment To A User Programmable Cable The Model HMCBL XX has a 15 pin D sub connector on one end for direct attachment to the PROBE INPUT connection on the back panel of the Model 455 Gaussmeter Four tinned wires are provided for connection to the Hall Generator The leads may be soldered directly to these wires The cable comes in two lengths the HMCBL 6 is 2 meters 6 fee
194. rators with sensitivities outside the above indicated ranges is discouraged All of the above entries will be stored in the HMCBL cable PROM located in the connector Thus any time the cable Hall generator combination is used the Model 455 will recognize the stored parameters and operation may proceed The HMCBL cables may be reprogrammed for other Hall generators as needed A Hall generator can be connected directly to the Model 455 without using an HMCBL cable Probe parameters can be configured as stated above but the settings will be lost if power is cycled 5 2 2 Ohms Measurement Mode The Model 455 may be configured to make a 4 lead resistive measurement If the sensitivity of the probe is set to 0 the instrument will read in ohms Instrument features are limited in this mode The following ranges are available in this mode 350 uQ 3 5 mQ 35 mQ 350 mQ and 3 5 Q 5 4 Advanced Operation Lake Shore Model 455 Gaussmeter User s Manual CHAPTER 6 COMPUTER INTERFACE OPERATION 6 0 GENERAL This chapter provides operational instructions for the computer interface for the Lake Shore Model 455 Gaussmeter Either of the two computer interfaces provided with the Model 455 permit remote operation The first is the IEEE 488 Interface described in Section 6 1 The second is the Serial Interface described in Section 6 2 The two interfaces share a common set of commands detailed in Section 6 3 Only one of the interfaces can be used at a
195. ric shock Background color Earth ground terminal Yellow Symbol and outline Black Caution or Warning See Protective conductor terminal A instrument documentation Background color Yellow Symbol Frame or chassis terminal and outline Black On supply Off supply Fuse O Or ede 1 8 Introduction Lake Shore Model 455 Gaussmeter User s Manual CHAPTER 2 BACKGROUND 2 0 GENERAL This chapter provides background information related to the Model 455 Gaussmeter It is intended to give the user insight into the benefits and limitations of the instrument and help apply the features of the Model 455 to a variety of experimental challenges It covers basic DSP concepts and how they are applied to the operation of the Model 455 flux density and Hall measurement and probe operation For information on how to install the Model 455 please refer to Chapter 3 Instrument operation information is contained in Chapter 4 and Chapter 5 2 1 MODEL 455 THEORY OF OPERATION 2 1 1 Sampled Data Systems Humans rely on analog signals to interact with their environment individual wavelengths of light are converted to colors pressure waves are interpreted as sound and the vibration of vocal cords creates speech In the fields of science and engineering a variety of sensors are used to convert analog signals of interest into some electrical property usually voltage so that they can be measured or used as an input to a
196. rogramming Numeric data entry within a setting sequence Increments a parameter selection or value in a numerical display Decrements a parameter selection or value in a numerical display Exits from parameter setting sequence without changing the parameter value Press and hold Escape for 6 seconds to view firmware date and for setting parameters to factory defaults Accepts changes in the parameter setting display Press and hold Enter to access the Keypad Lock feature Select DC Field measurement Press and hold to select Filter Select AC Root Mean Square RMS measurement Press and hold for RMS mode configuration Turns Max Hold feature ON and OFF Select Peak measurement Press and hold for peak configuration Turns Relative feature ON and OFF Reset max min or peak readings depending on which measurement is active Operation 4 3 Lake Shore Model 455 Gaussmeter User s Manual 4 3 2 General Keypad Operation The Model 455 uses four basic keypad operations direct operation press and hold setting selection and data entry for the majority of operator interface A few specialized keypad operations such as User cable and Probe extension cable programming are described in the individual operation paragraphs Direct Operation Occurs immediately when the key is pressed DC RMS Max Hold Peak Relative and Reset are examples of keys that operate this way Press and Hold Occurs when the key is pressed and held for approx
197. ront panel In DC measurement mode the keypad and functionality of the Model 455 is optimized to provide the best interaction for DC measurements The keypad features are described in paragraphs 4 6 1 through 4 6 7 4 6 1 DC Operation Select Range and Autorange The Model 455 reads each Lake Shore probe type High Stability High Sensitivity and Ultra High Sensitivity The tables below list full scale ranges for each probe sensitivity along with the maximum number of digits of display resolution Measurement resolution noise floor varies depending on probe and application High Stability Probe HST Gauss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 350 000 kG 35 0000 T 350 000 kOe 28 0000 MA m 35 0000 kG 3 50000 T 35 0000 kOe 2 80000 MA m 3 50000 kG 350 000 mT 3 50000 kOe 280 000 kA m 350 000 G 35 0000 mT 350 000 Oe 28 0000 kA m 35 0000 G 3 50000 mT 35 0000 Oe 2 80000 kA m High Sensitivity Probe HSE Gauss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 35 0000 kG 3 50000 T 35 0000 kOe 2 80000 MA m 3 50000 kG 350 000 mT 3 50000 kOe 280 000 kA m 350 000 G 35 0000 mT 350 000 Oe 28 0000 kA m 35 0000 G 3 50000 mT 35 0000 Oe 2 80000 kA m 3 50000 G 350 000 uT 3 50000 Oe 280 000 A m Ultra High Sensitivit
198. rs Counter used for Timing out Data string sent to instrument Show main window Terminators are lt CR gt lt LF gt Initialize counter Clear return string Clear holding string Close serial port to change settings Example of Comm 1 Example of 9600 Baud Parity Data Stop Read one character at a time Open port Wait loop Give up processor to other events Loop until Send button pressed Set Flag as false Get Command Clear response display Set all characters to upper case Get out on EXIT Send command to instrument Check to see if query Wait for response Add 1 to timeout if no character Wait for 10 millisecond timer Loop Until frmSerial Timerl Enabled False ZeroCount ZeroCount 1 Else ZeroCount 0 strHold frmSerial MSComm1 Input strReturn strReturn strHold End If Wend If strReturn lt gt Then strReturn Mid strReturn 1 InStr strReturn Else strReturn No Response End If frmSerial txtResponse Text strReturn strHold mn ZeroCount 0 If End Sub Timeout at 2 seconds Reset timeout for each character Read in one character Add next character to string Get characters until terminators Check if string empty Term 1 Strip terminators Send No Response Put response in textbox on main form Reset holding string Reset timeout counter Private Sub Timerl_Timer frmSerial Timerl
199. s reading the positive and negative full scale output voltages of each output calculating correction constants for gain and offset of each output and writing them back to appropriate calibration locations in the Model 455 These values are to be used whenever the outputs are accessed The gain and offset values should also be checked to assure that they are reasonable in value and reject them if they fall outside a given range Analog Output 2 uses slightly different full scale range since it is a 5 volt output that will never exceed 3 5 volts in normal operation 8 11 4 1 Analog Output 2 Calibration 1 Set Analog Output 2 Gain Correction Factor to 1 CALG 4 2 1 and Offset Correction Factor to 0 CALZ 4 2 0 Connect the DVM to Analog Output 2 Configure Analog Output 2 to manual mode 90 MOUT 1 90 Read the voltage using the DVM Record as VMIN Configure Analog Output 2 to manual mode 90 MOUT 1 90 Read the voltage using the DVM Record as VMAX Calculate the Gain Correction Factor GCF 9 VMAX VMIN Note Gain is calculated over the full span of the output Test this factor to be 1 0 1 Record this value Send the Gain Correction Factor GCF to the Model 455 CALG 4 2 lt GCF gt 9 Configure Analog Output 2 to manual mode 0 MOUT 1 0 10 Read the voltage using the DVM Record as VZERO 11 Calculate the Offset Correction Factor OCF VZERO 100 5 Note The offset voltage is expressed as a perce
200. s used with unit Place unit on a grounded conductive work surface Ground technician through a conductive wrist strap or other device using 1 MQ series resistor to protect operator Pooley Ground any tools such as soldering equipment that will contact unit Contact with operator s hands provides a sufficient ground for tools that are otherwise electrically isolated 5 Place ESDS devices and assemblies removed from a unit on a conductive work surface or in a conductive container An operator inserting or removing a device or assembly from a container must maintain contact with a conductive portion of the container Use only plastic bags approved for storage of ESD material 6 Do not handle ESDS devices unnecessarily or remove from the packages until actually used or tested 8 4 Service Lake Shore Model 455 Gaussmeter User s Manual 8 8 ENCLOSURE TOP REMOVAL AND REPLACEMENT WARNING To avoid potentially lethal shocks turn off controller and disconnect it from AC power line before performing this procedure Only qualified personnel should perform this procedure REMOVAL Set power switch to Off O and disconnect power cord from rear of unit piai If attached remove 19 inch rack mounting brackets Use 5 64 hex key to remove 4 screws attaching top panel to unit Use 5 64 hex key to loosen 2 screws attaching rear bottom panel to unit Carefully remove the back bezel by sliding it straight back away from the unit Aw on
201. se they have a flexible portion in the middle of their stem The active area at the tip remains rigid and somewhat exposed Flexible transverse probes are significantly more fragile than other transverse probes Flexible probes should only be select for applications that do not have direct access to the measured field with standard transverse or axial probes 7 2 Probes and Accessories Lake Shore Model 455 Gaussmeter User s Manual Tangential Tangential probes are special transverse versions designed to measure fields parallel to and near a surface The active area is very close to the stem tip These probes are intended for this special application and should not be selected for general transverse measurements Multiple Axis Multi axis probes are available for multi axis gaussmeters like the Lake Shore Model 460 These probes are not compatible with the Model 455 Frequency Hall effect gaussmeters like the Model 455 are equally well suited for measuring either static DC fields or periodic AC fields but proper probe selection is required to get optimal performance Metal Stem Metal stem probes are the best choice for DC and low frequency AC measurements Non ferrous metals are used for probe stems because they provide the best protection for the delicate Hall effect sensor Aluminum is the most common metal stem material but brass can also be used Metal stems do have one drawback eddy currents are formed in them when they are pla
202. ssed the maximum and minimum readings are cleared and reset with the present field reading 4 6 6 DC Operation Relative The relative function lets the user see small variations in larger fields When the relative function is on the relative readings will appear on the top line of the display including the small delta sign A signifying the relative display The displayed reading is equal to the present field value minus the relative setpoint The relative setpoint can be configured to be the present field reading or it can be a user defined value The relative setpoint can be displayed on the bottom display Refer to Section 4 4 1 To configure the relative setpoint press and hold the Relative key for approximately 4 seconds The relative setup screen appears as a prompt for selecting the source of the relative setpoint Use the A or W key to select Present Field or User Defined Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display To turn the relative function on press the Relative key The following screen will appear for approximately 3 seconds and the Relative LED will light The relative function also interacts with other features Relative can be used with Max Hold to display the maximum relative reading To turn the Relative function off press the Relative key 4 10 DC Operation Operation Lake Shore Mod
203. system Analog to digital converters ADC and digital to analog converters DAC allow computers in the digital domain to interact with these analog signals Digital signals are different from continuous analog signals in the fact that they are sampled in time and quantized in amplitude Both of these properties limit the ability of the digital representation to match the original analog signal An ADC will sample a signal at fixed intervals of time Quantization results from the fact that an ADC has a limited amount of resolution When both the sampling frequency and resolution are properly chosen however the digital signal is an accurate representation of the original analog signal The sampling frequency of the Model 455 allows an accurate RMS measurement to be made on signals of up to 20 kHz The sampling and filtering in the Model 455 can allow realizable resolutions of 20 bits which is in the noise floor of the instrument 2 1 2 Digital Signal Processing Digital Signal Processing DSP is the science of manipulating digital data through the use of mathematics The variety of processing that can be done is almost endless from simulating an analog filter to enhancing a visual image to encrypting sensitive information Digital Signal Processing is being used in more and more products due to its accuracy flexibility and reliability The Model 455 gaussmeter is an ideal product that can benefit from DSP technology The Model 455 offers the user
204. t and the HMCBL 20 is 6 meters 20 feet GT Green Wre CJ SES Red wire GJ Cabk to Hall voltage Blue Mire MHD Galseme Br TOM for Yellow Wire vy MCBL_Cable eps Figure 7 9 Model HMCBL XX User Programmable Cable Accessory CAUTION The Hall Generator should be isolated from all line voltages or voltages referenced to earth ground If not damage to the Model 455 Gaussmeter is almost a certainty IMPORTANT Refer to Section 7 5 5 for a partial list of compatible Hall generators manufactured by Lake Shore Once connections are made refer to Section 5 2 for instructions on programming parameters into the internal EPROM Probes and Accessories 7 11 Lake Shore Model 455 Gaussmeter User s Manual 7 5 5 Hall Generator Specifications This section covers three types of Hall generators available from Lake Shore HGCA amp HGCT Series Cryogenic Hall generators Figures 7 10 and 7 11 with specifications Table 7 1 HGA Series Axial Hall generators Figure 7 11 with specifications Table 7 2 and HGT Series Transverse Hall generators Figure 7 12 with specifications Table 7 3 OG tin 10 in gmin um F Lead Length 0240 in eeng a mg E imax E E Center of 1 Active Are 0043 in max Ceramic Case Cate C 455 C 6 eps Figure 7 10 Transverse Hall Generator HGT 3010 HGT 3030 and HGCT 3020 Dimensions Table 7 1 Cryogenic Hall Generator Specifications
205. t receives The response can be a reading value status report or the present value of a parameter Response data formats are listed along with the associated queries in Section 6 3 Remote Operation 6 3 Lake Shore Model 455 Gaussmeter User s Manual 6 1 4 Status System 6 1 4 1 Overview The Model 455 implements a status system compliant to the IEEE 488 2 1992 standard The status system provides a method of recording and reporting instrument information and is typically used to control the Service Request SRQ interrupt line A diagram of the status system is shown in Figure 6 1 The status system is made up of register sets the Status Byte register and the Service Request Enable register Each register set consists of three types of registers condition event and enable 6 1 4 1 0 Condition Registers Each register set except the Standard Event Register set includes a condition register as shown in Figure 6 1 The condition register constantly monitors the instrument status The data bits are real time and are not latched or buffered The register is read only 6 1 4 1 1 Event Registers Each register set includes an event register as shown in Figure 6 1 Bits in the event register correspond to various system events and latch when the event occurs When an event bit is set subsequent events corresponding to that bit are ignored Set bits remain latched until the register is cleared by a query command such as ESR or a C
206. table Max reading rate periodic mode 30 rdg s Peak accuracy 5 Hz to 20 kHz 4 2 of reading gt 1 of full scale range 50 us or longer pulse width Peak frequency range periodic mode 50 Hz to 5 kHz Peak frequency range pulse mode 5 Hz to 20 kHz Temperature Measurement Temperature range Probe dependent typically 0 to 75 C Measurement resolution 0 01 C Temperature display resolution 0 01 C Electronic accuracy 0 7 C Introduction Lake Shore Model 455 Gaussmeter User s Manual Specifications Continued Front Panel Display type 2 line x 20 character vacuum fluorescent with 9 mm high characters Display resolution To 5 digits Display update rate 5 rdg s Display units gauss G tesla T oersted Oe and ampere per meter A m Units multipliers u m k M Display annunciators DC measurement mode AC RMS measurement mode Peak measurement mode Max hold value Min hold value Relative setpoint value LED annunciators Relative Relative reading mode Alarm Alarm active Remote Remote IEEE 488 operation Keypad 22 full travel keys Front panel features Display prompts front panel lock out and brightness control Interfaces RS 232C Baud 9600 19200 38400 and 57600 Update rate 30 rdg s Software support Lab V IEW driver Connector 9 pin D style DTE configuration IEEE 488 2 Capabilities SH1 AH1 T5 L4 SR1 RL1 PPO DC1 DTO CO and E1 Update rate 30 rdg s So
207. tance measurement mode The remaining ranges are calibrated by using the previous calibrated range as shown in the following steps 1 Set the Gain Correction Factor to 1 for all five of the 10 mA hall current source ranges CALG 2 1 1 CALG 2 2 1 Connect the 33 2 Q resistor to the DVM using a proper 4 lead connection Read the resistor using the DVM Store as EXPECTEDRESISTANCE Connect a short across the Gaussmeter input of the Model 455 using a proper 4 lead connection Configure the Model 455 for 10 mA excitation current HALLCS 2 Configure the Model 455 for DC 5 digits RDGMODE 1 3 1 1 1 on the 35 Q range RANGE 5 Zero the probe using the Zero Probe key or the ZPROBE command Connect the 33 2 Q resistor across the Gaussmeter input of the Model 455 using a proper 4 lead connection Configure the Model 455 for 10 mA excitation current HALLCS 2 Read the resistor using the Model 455 RDGOHM Store as ACTUALRESISTANCE Calculate the Gain Calibration Factor GCF EXPECTEDRESISTANCE ACTUALRESISTANCE Test this factor to be 1 0 43 12 Send the Gain Calibration Factor GCF to the Model 455 CALG 2 5 lt GCF gt 13 Read the resistor using the Model 455 RDGOHM Verify the reading to be EXPECTEDRESISTANCE 0 02 14 Connect the 3 resistor across the Gaussmeter input of the Model 455 using a proper 4 lead connection 15 Configure the Model 455for 10 mA excitation current HALLCS 2 16 Read the resistor using the Model 4
208. tential difference b magnetomotive force U F gilbert Gb 10 47 Magnetic field strength Volume magnetization Volume magnetization bami HH Lake Shore Model 455 Gaussmeter User s Manual APPENDIX A UNITS FOR MAGNETIC PROPERTIES Table A 1 Conversion from CGS to SI Units Gaussian Conversion SI amp amp CGS emu Factor CH Rationalized mks G weber Wb volt Quantity Symbol Magnetic induction Magnetic Flux ampere A H oersted Oe Gb cm 108 47 A m magnetizing force B B 4nM 10 4n Al Magnetic polarization 3 4 2i intensity of magnetization i emu cm 4n x 10 T Wb m Magnetic dipole moment Volume susceptibility Volume energy density Demagnetization factor Mass magnetization Mass susceptibility Molar susceptibility Relative permeability ee AN a z H Am kg Re 4nx 1077 Wb m kg Am joule per tesla erg G 103 Or Pi j EC KEE el T Wot LK dimensionless Henry per meter emu cm 4x x 107 H m Wb A m 3 4r x 10 m kg Xp Kp cure emu g 4n 2 x 10 19 H m kg 4r x 10 3 mol YX mol Kmol cm mol emu mol Any x i v ir Wee 8 Him WAT notdefined ER dimensiontes erg cm 101 J m DN dimensionless 0 M Al 1 Magnetic moment Permeability energy product NOTES a Gaussian units and cgs emu are the same for magnetic properties The defining relation is B H 42M b Multiply a number in Gaussian units by C to
209. that an enabled operation event has occurred Request Service RQS Master Summary Status MSS Bit 6 This bit is set when a summary bit and the summary bits corresponding enable bit in the Service Request Enable Register are set Once set the user may read and clear the bit in two different ways which is why it is referred to as both the RQS and the MSS bit When this bit goes from low to high the Service Request hardware line on the bus is set this is the RQS function of the bit Refer to Section 6 1 4 3 3 In addition the status of the bit may be read with the STB query which returns the binary weighted sum of all bits in the Status Byte this is the MSS function of the bit Performing a serial poll will automatically clear the RQS function but not the MSS function A STB will read the status of the MSS bit along with all of the summary bits but also will not clear it To clear the MSS bit either clear the event register that set the summary bit or disable the summary bit in the Service Request Enable Register Event Summary ESB Bit 5 Set summary bit indicates that an enabled standard event has occurred Message Available MAV Bit 4 Set summary bit indicates that a message is available in the output buffer Bit 3 Not used Bit 2 Not used Bit 1 Not used Bit 0 Not used 6 8 Remote Operation Lake Shore Model 455 Gaussmeter User s Manual 6 1 4 3 2 Service Request Enable Register
210. the expression Vu Yg B sin 8 where Vj Hall voltage mV Yg Magnetic sensitivity mV kG at a fixed current B Magnetic field flux density kilogauss 6 Angle between magnetic flux vector and the plane of Hall generator As can be seen from the formula above the Hall voltage varies with the angle of the sensed magnetic field reaching a maximum when the field is perpendicular to the plane of the Hall generator 2 4 Background Lake Shore Model 455 Gaussmeter User s Manual 2 3 1 Active Area The Hall generator assembly contains the sheet of semiconductor material to which the four contacts are made This entity is normally called a Hall plate The Hall plate is in its simplest form a rectangular shape of fixed length width and thickness Due to the shorting effect of the current supply contacts most of the sensitivity to magnetic fields is contained in an area approximated by a circle centered in the Hall plate whose diameter is equal to the plate width Thus when the active area is given the circle as described above is the common estimation v Ic f Red Conventional Current F e v x B force on electron n Ee lt Blue Clear or Yellow a High Mobility II V Semiconductor a Indium arsenide b Gallium arsenide wl lc Green or Black 455_Hall_6 bmp Figure 2 6 Hall Generator Theory Background 2 5 Lake Shore Model 455 Gaussmeter User s Manual 2 3 2 P
211. time 6 1 IEEE 488 INTERFACE The IEEE 488 Interface is an instrumentation bus with hardware and programming standards that simplify instrument interfacing The Model 455 IEEE 488 Interface complies with the IEEE 488 2 1987 standard and incorporates its functional electrical and mechanical specifications unless otherwise specified in this manual All instruments on the interface bus perform one or more of the interface functions of TALKER LISTENER or BUS CONTROLLER A TALKER transmits data onto the bus to other devices A LISTENER receives data from other devices through the bus The BUS CONTROLLER designates to the devices on the bus which function to perform The Model 455 performs the functions of TALKER and LISTENER but cannot be a BUS CONTROLLER The BUS CONTROLLER is the digital computer which tells the Model 455 which functions to perform Below are Model 455 IEEE 488 interface capabilities e SH1 Source handshake capability e RLI Complete remote local capability e DCL Full device clear capability e DT0 No device trigger capability e CO No system controller capability e T5 Basic TALKER serial poll capability talk only unaddressed to talk if addressed to listen e L4 Basic LISTENER unaddressed to listen if addressed to talk e SR1 Service request capability e AH1 Acceptor handshake capability e PPO No parallel poll capability e El Open collector electronics Instruments are connected to the IEEE 488 bus by a 24
212. tion 4 1 Lake Shore Model 455 Gaussmeter User s Manual 4 2 DISPLAY DEFINITION In normal operation the two row by twenty character vacuum fluorescent display provides readings defined by the selected measurement features on the top row and special information or readings on the bottom row The bottom row can be configured under most operating conditions refer to Section 4 4 This paragraph describes features of the display that appear during normal operation including field measurement temperature measurement and frequency Other information displays when using the various functions on the keypad Field Units Probe Orientation kG G mG G DC Relative DC and Peak T mT uT PK On kOe Oe mOe Oe PK Mx Field Reading A m kA m MA m RMS Mn Temperature Reading ae rae Frequency Reading Ge SC Lower row is a user defined display area configured here with a temperature and frequency display C 455 4 2 bmp Figure 4 2 Front Panel Display Definition 4 2 1 Display Units Field in Gauss Field in Tesla Field in Oersted Field in Amp meter Resistance in Ohms Maximum and Minimum from Max Hold Positive and Negative Peak readings DC or RMS mode readings Frequency of RMS fields in Hz Probe Temperature in Kelvin Probe Temperature in Celsius 4 2 2 Display and LED Annunciators There are also feature annunciators that appear as necessary to indicate additional information Display annunciators are visible when their associat
213. tion 4 17 Lake Shore Model 455 Gaussmeter User s Manual 4 8 6 Peak Operation Relative The relative function lets the user see small variations in larger fields When the relative function is on the relative readings will appear on the top line of the display including the small delta sign A signifying the relative display The displayed reading is equal to the present field value minus the relative setpoint The relative setpoint can be configured to be the present field reading or it can be a user defined value The relative setpoint can be displayed on the bottom display Refer to Section 4 4 1 To configure the relative setpoint press and hold the Relative key for approximately 4 seconds The relative setup screen appears as a prompt for selecting the source of the relative setpoint Use the A or V key to select Present Field or User Defined Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display To turn the relative function on press the Relative key The following screen will appear for approximately 3 seconds and the Relative LED will light The relative function also interacts with other features Relative can be used with Max Hold to display the maximum relative reading To turn the Relative function off press the Relative key If the relative mode is configured to use the present field as the setpoint th
214. to add the following files Niglobal bas and Vbib 32 bas 5 Add controls to form a Add three Label controls to the form b Add two TextBox controls to the form c Add one CommandButton control to the form 6 On the View Menu select Properties Window 7 Inthe Properties window use the dropdown list to select between the different controls of the current project 8 Set the properties of the controls as defined in Table 6 4 9 Save the program Remote Operation 6 13 Lake Shore Model 455 Gaussmeter User s Manual Table 6 4 IEEE 488 Interface Program Control Properties Current Name Property New Value Label Name IbIExitProgram Caption Type exit to end program Label2 Name Ib1Command Caption Command Label3 Name IbIResponse Caption Response Textl Name txtCommand Text lt blank gt Text2 Name txtResponse Text lt blank gt Command1 Name cmdSend Caption Send Default True Form Name frmIEEE Caption IEEE Interface Program 10 Add code provided in Table 6 5 a In the Code Editor window under the Object dropdown list select General Add the statement Public gSend as Boolean b Double Click on cmdSend Add code segment under Private Sub cmdSend_Click as shown in Table 6 5 c Inthe Code Editor window under the Object dropdown list select Form Make sure the Procedure dropdown list is set at Load The Code window should have written the segment of code Privat
215. tors CR LF LF CR LF and EOI The default is Cr Lf Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 6 1 2 Remote Local Operation Normal operations from the keypad are referred to as Local operations The Model 455 can also be configured for Remote operations via the IEEE 488 interface or the Local key The Local key will toggle between Remote and Local operations During Remote operations the Remote LED annunciator will light and operations from the keypad will be disabled 6 1 3 IEEE 488 Command Structure The Model 455 supports several command types These commands are divided into three groups 1 Bus Control Refer to Section 6 1 3 1 a Universal 1 Uniline 2 Multiline b Addressed Bus Control 2 Common Refer to Section 6 1 3 2 3 Device Specific Refer to Section 6 1 3 3 Message Strings Refer to Section 6 1 3 4 6 1 3 1 Bus Control Commands A Universal Command addresses all devices on the bus Universal Commands include Uniline and Multiline Commands A Uniline Command Message asserts only a single signal line The Model 455 recognizes two of these messages from the BUS CONTROLLER Remote REN and Interface Clear IFC The Model 455 sends one Uniline Command Service Request SRQ REN Remote Puts the Model 455 into remote mode IFC Interface Clear Stops current operat
216. try keys to enter the low setpoint between 350 kG or equivalent depending on selected field units Enter the numeric value first Press Enter to accept the new value and advance to the units multiplier Use the A or V key to select a units multiplier of u m blank k or M depending on selected field units Press Enter to accept the new selection and continue to the next setting screen Press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display The next alarm setup screen appears as a prompt for the high alarm setpoint value Use the data entry keys to enter the high setpoint between 350 kG or equivalent depending on selected units Enter the numeric value first Press Enter to accept the new value and advance to the units multiplier Use the A or V key to select a units multiplier of u m blank k or M Press Enter to accept the new selection and return to the normal display Press Escape to restart the setting sequence and enter a new value Press Escape again to cancel the sequence and return to the normal display Operation 4 19 Lake Shore Model 455 Gaussmeter User s Manual The alarm may be configured to use the magnitude of the field reading only ignoring the sign or to include the sign and treat the readings algebraically To configure the alarm for magnitude or algebraic mode press and hold the Alarm key for approximately 4 seconds
217. ty is mistakenly entered the Model 455 reverts to resistance measurement otherwise the instrument will use the previously loaded sensitivity 5 2 1 User Programmable Cable If the Model 455 detects the presence of a HMCBL cable with no sensitivity information a new blank cable the instrument will display a message indicating Invalid Probe Press the Enter button to clear the message The instrument will jump directly to the probe setup screens beginning with the probe serial number entry screen If the instrument is already displaying a reading the probe information may be changed To configure the HMCBL cable press and hold the Probe key for approximately 4 seconds The following screen appears as a prompt for selecting the programming method Use the A or V key to select the MCBL Program user programmable cables Press Enter to accept the new selection and continue to the next setting screen Press Escape to cancel the selection and return to the normal display If an invalid HMCBL cable is attached for instance a fully calibrated Lake Shore probe and the MCBL program is attempted the following message will appear for approximately 5 seconds If this occurs verify that the cable is properly connected If the invalid message continues either replace the cable with a proper HMCBL cable or contact Lake Shore Service Advanced Operation 5 3 Lake Shore Model 455 Gaussmeter User s Manual
218. uld not be dropped or physically abused Magnets of this type can have magnetic reference values ranging from 100 G to 20 kG but the most widely used value is 1 kG Reference magnet accuracy is typically 0 5 except for magnets of 200 G or less for these magnets the limit of error is generally 1 The reference magnet gap is nominally 0 060 inch but may range from 0 040 to 0 250 inch for special units The usable plateau in the reference gap generally encompasses an area of about 0 5 square inches In reference magnets used for axial field probes Alnico V or VI is the usual magnet material charged to saturation and stabilized down to a particular value The same temperature coefficients hold true as in the transverse probe and the same care in handling must be observed This assembly uses concentric mu metal shield cans to protect the magnet from the effects of external magnetic field Axial reference magnets are available in values up to 2 kG with 500 G being the most widely used value When a probe is inserted completely through the access guide three distinct magnetic peaks will be observed on the gaussmeter One peak occurs as the probe enters the magnet a second and greater peak is observed as the midpoint is reached and a third smaller peak is read as the probe leaves the magnet The calibration point is the largest reading in the midpoint area Its amplitude will be approximately twice that of the readings that occur where the probe e
219. um continuous current non heat 300 mA 300 mA sinked Magnetic sensitivity I nominal control 0 55 to 1 05 mV kG 6 0 to 10 0 mV kG current Maximum linearity error sensitivity 1 RDG 30 to 30 kG 0 30 RDG 10 to 10 kG versus field 1 5 RDG 100 to 100 kG 1 25 RDG 30 to 30 kG Zero field offset voltage Ic nominal 50 uV max 75 uV max control current Operating temperature range 40 to 100 C 40 to 100 C Mean temperature coefficient of magnetic 0 005 C max 0 04 C max sensitivity Mean temperature coefficient of offset Ic 0 4 uV C max 0 3 uV C max nominal control current Mean temperature coefficient of resistance 0 15 C approx 0 18 C approx Leads 34 AWG copper with poly nylon 34 AWG copper with poly nylon insulation insulation Probes and Accessories 7 13 Lake Shore Model 455 Gaussmeter User s Manual _ OA in 10 in min 0 125 hi elero Acte Area F EE ke 200 e Rm em e e ep mme MTA x oer Hall plate 01 028 in fmax oer leads 0 130 in fmax C 455 C 7 eps Figure 7 12 Transverse Hall Generator HGT 1010 Dimensions Table 7 3 Transverse Hall Generator Specifications HGT 1010 HGT 3010 HGT 3030 Description General purpose transverse Instrumentation quality Instrumentation quality 0 020 inch thick transverse low temperature transverse ceramic package co
220. utput can be used to view a pulse shape or other characteristic of a momentary signal Output 1 serves only as a diagnostic tool in DC and narrow band AC modes because modulation of the probe signal prevents a clear view of the field response Introduction 1 3 Lake Shore Model 455 Gaussmeter User s Manual Display and Interface Features Continued Voltage Output 2 The second voltage output provides a voltage proportional to measured field with the benefits of some signal processing The output is produced by the DSP through a fast D A converter The output signal is updated at 40 kHz giving good response for low to mid frequency fields Signal quality degrades at high frequency because of the sampling rate This voltage can be corrected for probe offset and for the nominal sensitivity of the probe Voltage Output 3 The third output provides a voltage proportional to measured field with the most signal processing of the three outputs All probe compensation available to the display readings including temperature compensation can be performed on this output The output is produced by the micro processor through a 16 bit D A converter updated at 30 readings per second Computer Interface Two computer interfaces are included with the Model 455 serial RS 232C and parallel IEEE 488 Both allow setup of all instrument parameters and read back of measured values The reading rate over the interface is nominally 30 readings per second LabV
221. ximum stored field readings and sets them equal to the present reading MODE Remote Interface Mode Command Input MODE lt mode gt term Format n lt mode gt 0 local 1 remote 2 remote with local lockout Example MODE 2 term Places the Model 455 into remote mode with local lockout MODE Remote Interface Mode Query Input MODE term Returned lt mode gt term Format n Refer to command for description Remote Operation 6 31 Lake Shore Model 455 Gaussmeter User s Manual OPST Input Returned Format Remarks OPSTE Input Format Remarks OPSTE Input Returned Format OPSTR Input Returned Format Remarks PKRST Input Remarks Operational Status Query OPST term lt bit weighting gt term nnn The integer returned represents the sum of the bit weighting of the operational status bits Refer to Section 6 1 4 2 2 for a list of operational status bits Operational Status Enable Command OPSTE lt bit weighting gt term nnn Each bit has a bit weighting and represents the enable disable mask of the corresponding operational status bit in the Operational Status Register This determines which status bits can set the corresponding summary bit in the Status Byte Register To enable a status bit send the command OPSTE with the sum of the bit weighting for each desired bit Refer to Section 6 1 4 2 2 for a list of operational status bits Operational
222. y Lake Shore Cryotronics Inc All rights reserved No portion of this manual may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the express written permission of Lake Shore Lake Shore Model 455 Gaussmeter User s Manual CE DECLARATION OF CONFORMITY We Lake Shore Cryotronics Inc 575 McCorkle Bivd Westerville OH 43082 USA hereby declare that the equipment specified conforms to the following Directives and Standards Application of Council Directives 2006 95 EC LVD 2004 108 EC EMC Standards to which Conformity is declared EN 61010 1 2010 Overvoltage II Pollution Degree 2 EN 61326 1 2013 Class A Annex B Ne NUMDE ege Eeer 455 Scott Ayer d AA al ea i Director of Quality and Compliance Position The Model 455 is considered Waste Electrical and Electronic Equipment WEEE Category 9 equipment therefore falling outside the current scope of the RoHS directive However in recognition that ROHS compliance is in the best interest of our customers employees and the environment Lake Shore has designed the Model 455 instrument to eliminate the hazardous substances covered in the RoHS directive Although the instrument itself does not contain any of these restricted materials the Hall probes and generators used with it do contain them which makes the instrument not RoHS compliant Lake Shore
223. y Probe UHS Gauss Tesla Oersted Amp meter Range and Resolution Range and Resolution Range and Resolution Range and Resolution 35 0000 G 3 50000 mT 35 0000 Oe 2 80000 kA m 3 50000 G 350 000 uT 3 50000 Oe 280 000 A m 350 000 mG 35 0000 uT 350 000 mOe 28 0000 A m 35 0000 mG 3 50000 uT 35 0000 mOe 2 80000 A m For manual ranging press the Select Range key The range setup screen appears as a prompt for changing the range Use the A or V key to select from the available ranges Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display DC Operation Operation Lake Shore Model 455 Gaussmeter User s Manual Selecting the range this way will disable the Auto Range function To enable the Auto Range function press Autorange The autorange setup screen appears as a prompt for turning the Auto Range function on or off Use the A or F key to select from Off or On Press Enter to accept the new selection and return to the normal display Press Escape to cancel the new selection and return to the normal display 4 6 2 DC Operation Resolution and Filtering The firmware linear filter is an integral part of the Model 455 DC measurement It is directly related to measurement resolution frequency response and reading rate Reading rates up to 30 readings per second are only available over the
224. y using the previous calibrated range as shown in the following steps Set the Gain Correction Factor to for all five of the 1 mA hall current source ranges CALG 3 1 1 CALG 3 2 1 Connect the 332 Q resistor to the DVM using a proper 4 lead connection Read the resistor using the DVM Store as EXPECTEDRESISTANCE Connect a short across the Gaussmeter input of the Model 455 using a proper 4 lead connection Configure the Model 455 for 1 mA excitation current HALLCS 3 Configure the Model 455 for DC 5 digits RDGMODE 1 3 1 1 1 on the 350 range RANGE 5 Zero the probe using the Zero Probe key or the ZPROBE command Connect the 332 Q resistor across the Gaussmeter input of the Model 455 using a proper 4 lead connection Configure the Model 455for 1 mA excitation current HALLCS 3 Read the resistor using the Model 455 RDGOHM Store as ACTUALRESISTANCE Calculate the Gain Calibration Factor GCF EXPECTEDRESISTANCE ACTUALRESISTANCE Test this factor to be 1 0 3 12 Send the Gain Calibration Factor GCF to the Model 455 CALG 3 5 lt GCF gt 13 Read the resistor using the Model 455 RDGOHM Verify the reading to be EXPECTEDRESISTANCE 0 02 14 Connect the 33 2 Q resistor across the Gaussmeter input of the Model 455 using a proper 4 lead connection 15 Configure the Model 455 for 1 mA excitation current HALLCS 3 16 Read the resistor using the Model 455 RDGOHM Store as EXPECTEDRESISTANCE 17 Configure the Model 45

Lake Shore Model 455 DSP Gaussmeter Manual

Contents

Download Pdf Manuals

Related Search

Related Contents