Model 475 Datasheet
Contents
1. 3 ussmeter www lakeshore com Analog Zero Loca Output Gontrol Display Autorange Probe Escape told Peak i m e M he Select am Relay jg Unt Range Prot The First Gaussmeter with DSP Technology lL akeShnore Model 475 DSP Gaussmeter BI Full scale ranges from 35 mG to 350 kG B DC measurement resolution to 0 02 mG W Basic DC accuracy of 0 05 lI DC to 50 kHz frequency range probe dependent la 15 band pass and 3 low pass AC filters W Peak capture to 20 us pulse widths WE Data buffer sampling rates to 1000 readings s WE Computer interface sampling rates to 100 new readings s WE Integrated electromagnet field control algorithm WE Standard and custom probes available The First Gaussmeter with DSP Technology The First DSP Gaussmeter Lake Shore combined the technical advantages of digital signal processing with over a decade of experience in precision magnetic field measurements to produce the first commercial digital signal processor DSP based Hall effect gaussmeter the Model 475 DSP technology creates a solid foundation for accurate stable and repeatable field measurement while simultaneously enabling the gaussmeter to offer an unequaled set of useful measurement features The Model 475 is intended for the most demanding DC and AC applications In many cases it provides the functionality of two or more instruments in a field measurement system The pow2. 000 001 kG 000 01 kG 000 1 kG 35 kG 00 0001 kG 00 001 kG 00 01 kG 3 5 kG 0 00001 kG 0 0001 kG 0 001 kG 350 G 000 003 G 000 02 G 000 1 G 39 G 00 0030 G 00 015 G 00 04 G HSE Probe 35 kG 00 0001 kG 00 001 kG 00 01 kG 3 5 kG 0 00001 kG 0 0001 kG 0 001 kG 390 G 000 001 G 000 01 G 000 1 G 35 G 00 0003 G 00 002 G 00 01 G 39G 0 00030 G 0 0015 G 0 004 G UHS Probe 39 G 00 0001 G 00 001 G 00 01 G 39G 0 00001 G 0 0001 G 0 001 G 350 mG 000 003 mG 000 02 mG 000 1 mG 3o mG 00 0030 mG 00 015 mG 00 04 mG Probe Type 454 digit Ranges Resolution HST Probe 350 kG 000 01 kG 35 kG 00 001 kG 3 5 KG 0 0002 kG 350 G 000 02 G 35 G 00 020 G HSE Probe 35 kG 00 001 kG 3 5 kG 0 0001 kG 350 G 000 02 G 35G 00 002 G 3 5 G 0 0020 G UHS Probe 35G 00 001 G 39G 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 shorted input Display resolution Indicated by number of digits in above table Max reading rate 30 rdgs s 100 to 1000 rdgs s limited feature set interface dependent AC accuracy 1 of reading AC frequency range 1 Hz to 1000 Hz narrow band mode 50 Hz to 20 kHz wide band mode AC band limiting filters 18 user selected frequencies of 3 low pass or 15 band pass 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 re
3. ASCII format mode which is a 30 KG This reduces interface overhead natural extension enabling real time reading rates up of the high speed to 100 new readings per second data acquisition Temperature compensation is not necessary for DSP available at the highest interface rate operation Fast instrument sample Data Buffer rates permit capture of Internal memory provides storage positive and negative for 1024 field readings in a data field pulses as narrow as buffer The buffer can be filled at 20 ps in width which 40 us 60 us high speed up to 1000 readings per can be held for an Time second which is as much as ten times unlimited length of time with faster than the computer interface no sag This is ideal for most magnetizers and other fast pulse applications For more Stored readings can then be retrieved moderate field changes the Model 475 can process the captured data to create other over interface at slower speed and features The gaussmeter can be configured to follow the peak of a periodic waveform processed off line A trigger input for evaluation of crest factor The Model 475 can also be used to sample field changes can be used to initiate the data log at 1000 readings per second that can later be read over the interface to illustrate the sequence Slower sample rates can be shape of pulses or other waveforms programmed if desired Trigger In and Trigger Out A TTL level hardware trigger into the instrument can be used to
4. Hall Probe Selection Guide Listed below with specifications are the commonly used probes for the Model 475 gaussmeter Other standard probes are available Lake Shore prides itself on making every attempt to satisfy customer requests for special probes If you need a custom probe contact Lake Shore for availability All probes shown contain temperature sensors Axial Probes cable length 2 25 in 57 mm L 6 6 ft 2 m ig M sem Dow c a B 0 36 0 030 in diameter 9 1 0 76 mm Stem Frequency Probe type Corrected Operating Temperature Temperature material range accuracy temperature coefficient coefficient of reading range maximum maximum zero calibration 2in 0 063in 0 25 in dia 0 015 in Aluminum DC to 10 kHz HSE 0 20 to 0 09G C 0 015 C 0 006 in 0 005 in 30 kG 4 in 0 125 in 0 187 in dia 0 005in X 0 030 india Fiberglass DC to 20 kHz 0 C to 0 005 in 0 003 in approx epoxy 75 C 2in 0 063in 0 25 in dia 0 015 in Aluminum DC to 400 Hz HST 2 0 10 to 0 13G PC 0 00595 C 0 006 in 0 005 in 30 kG 4 in x0 125 in 0 187 in dia 0 005 in Fiberglass DC to 800 Hz 0 005 in 0 003 in epoxy Transverse Probes cable length 2 5 in 64 mm L 6 6 ft 2 m nmm T B LURGI Ao 1 ER 0 030 in diameter 9 1 0 76 mm Active Stem Frequency Probe type Corrected Operating Temperature Temperature area material range
5. accuracy temperature coefficient coefficient of reading range maximum maximum zero calibration 4 in 0 061in 0 180in Aluminum DC to 800 Hz HSE 0 20 to 0 09 GC 0 015 C 0 125 in max 0 005 in 30 kG 4 in 0 045in 0 150 in 0 150 0 040in dia Fiberglass DC to 20 kHz 0 C to 0 125 in max 0 005in 0 005in approx epoxy 75 C 4 in 0 061in 0 180 in Aluminum DC to 400 Hz HST 2 0 10 to 0 13G C 0 00595 C 0 125 in max 0 005 in 30 kG 4 in 0 045in 0 150 in Fiberglass DC to 800 Hz z 0 125 in max 0 005 in epoxy www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com Flexible Transverse Probes 4 2 5 in 64 mm SE cable length 0 125 in diameter max Ed 4 6 6 ft 2 m 3 18 mm mE Lancy Wc L SEE 0 36 0 030 in diameter 9 1 0 76 mm T T L Stem Frequency Probe type Corrected Operating Temperature Temperature material range accuracy temperature coefficient coefficient of reading range maximum maximum zero calibration 0 135 in 0 025in 0 125 in 3 in 0 375in 0 040 in Flexible DC to 20 kHz HSE 0 20 to 0 C to 0 09 GC 0 015 C max max 0 005 in dia tubing 30 kG 75 C approx DC to 800 Hz HST 2 0 10 to 0 13G C 0 005 C 30 kG Gamma Probes 6 6 ft 2 m W EE Pit active sensing length t 3 125 in 79 4 mm cable length mE L EE PO to center
6. 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 have a flexible portion in the middle of their stem while the active area at the tip remains rigid and somewhat exposed This unique feature makes them significantly more fragile than other transverse probes Flexible probes should only be selected for narrow gap measurement applications Tangential Tangential probes are transverse probes 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 specific application and should not be selected for general transverse measurements www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com Frequency Nominal Active Area Hall effect gaussmeters like the Model 475 are equally _ HSE and HST probes have a nominal active area on the order well suited for measuring either static DC fields or periodic of 1 mm diameter which is useful for all but the most AC fields but proper probe selection is required to achieve stringent applications The measured field is the average of optimal performance the active area but without severe gradients the measured value accurately represents the true field Field mapping with Metal Stem standard probes is also practical
7. if a mapping resolution of Metal stem probes are the best choice for DC and low frequency 1 mm or greater is acceptable AC measurements Non ferrous metals are used for probe stems because they provide the best protection for the delicate Small Active Area Hall effect sensor Aluminum is the most common metal stem HSE and HST probes with a smaller active area are also material but brass can also be used Metal stems do have one available from Lake Shore for measurements in severe drawback eddy currents are formed in them when they are gradients or for high resolution mapping applications placed in AC fields These eddy currents oppose the field and cause measurement error The error magnitude is proportional UHS Probes to frequency and is most noticeable above 800 Hz UHS probes have a very large active length up to 3 5 in 8 9 cm They are designed to measure very small ambient Non metal Stem fields with little gradient Non metal stems are required for higher frequency AC fields and for measuring pulse fields Fiberglass epoxy is a common non metal stem material or the Hall effect sensor can be left exposed on its ceramic substrate This provides less protection for the sensor Eddy currents do not limit the frequency range of these non conductive materials but other factors may Probe Durability All Hall effect probes are fragile The sensor normally located at the tip of the probe stem must not be bent physically shock
8. units Gauss G Tesla T Oersted Oe and Ampere per meter A m Units multipliers u m k M Display annunciators DC DC measurement mode RMS AC RMS measurement mode PK Peak measurement mode MX Max Hold value MN Min Hold value SP Relative setpoint value CSP Field Control 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 lockout and brightness control Interfaces RS 232C Baud 9600 19200 38400 and 57600 Update rate 30 rdgs s ASCII Software support LabVIEW driver consult Lake Shore for availability Connector 9 pin D style DTE configuration IEEE 488 2 Capabilities SH1 AH1 T5 L4 SR1 RL1 PPO DC1 DT1 CO and E1 Update rate 30 rdgs s ASCII to 100 rdgs s binary no temperature compensation Software support LabVIEW driver consult Lake Shore for availability Data Buffer Capacity 1024 field readings Reading rate 1 to 1000 rdgs s Data transfer Through computer interface after data is logged Trigger Hardware trigger to begin data log sequence Alarm Settings High low setpoint Inside Outside Audible and Sort 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
9. EC 25 HMPEC 25 U HMPEC 50 HMPEC 50 U HMPEC 100 HMPEC 100 U User programmable cable with EEPROM 6 ft Probe extension cable with EEPROM 10 ft calibrated Probe extension cable with EEPROM 10 ft uncalibrated Probe extension cable with EEPROM 25 ft Probe extension cable with EEPROM 25 ft uncalibrated Probe extension cable with EEPROM 50 ft calibrated Probe extension cable with EEPROM 50 ft uncalibrated Probe extension cable with EEPROM 100 ft calibrated Probe extension cable with EEPROM 100 ft uncalibrated calibrated Extension cables must be matched to probes Calibration Service CAL 475 CAL 475DATA Instrument calibration Instrument calibration with report and data All specifications are subject to change without notice 11 OM www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com akeShore Lake Shore Cryotronics Inc 575 McCorkle Boulevard Westerville OH 43082 USA Tel 614 891 2244 Fax 614 818 1600 e mail sales lakeshore com www lakeshore com Established in 1968 Lake Shore Cryotronics Inc is an international leader in developing innovative measurement and control solutions Founded by Dr John M Swartz a former professor of electrical engineering at the Ohio State University and his brother David Lake Shore produces equipment for the measurement of cryogenic temperatures magnetic fields and the characterizat
10. ative 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 475 allows users to field calibrate the instrument if necessary Recalibration requires a computer interface and precision low resistance standards of known value Instrument Probe Features The Model 475 has several capabilities that allow the best possible measurements with Lake Shore probes These 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 non linearities present in each individual device can be measured and subtracted from the field reading Model 475 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 sensitivity temperature effects can be measured and subtracted out of field readings A temperature sensor in the pr
11. 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 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 This output can also be used for field control Computer Interface Two computer interfaces are included with the Model 475 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 but ranges from 10 to 100 readings per second are available LabVIEW drivers are provided to instrument users consult Lake Shore for availability SERIAL I O DTE pede TT SERVICE PERSONNEL EN ea her 475000B PROBE INPUT www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com Choosing a Hall Effect Probe Proper selection of a Hall probe is probably the most difficult and important decision to make after choosing the Model 475 Using the improper probe could lead to less than optimal accuracy or even worse costly damage The n
12. ctive area HSE probes are offered in the same geometries as HST probes Ultra High Sensitivity UHS Low magnitude large volume fields are most effectively measured with ultra high sensitivity probes which have unbeatable low field resolution to 0 02 mG 2 nT UHS probes or gamma probes are ideal for measuring fringe fields or variations in the earth s field They should never be used in fields over 30 G UHS probes are larger than other probes and have a very large active area making them impractical for small volume fields or tight spaces Orientation Usable Field Ranges 30 G 35 G 3 50 3o mG 390 G 390 G 35 G 350 mG 3 5 KG 3 5 KG 350 G 250 35 kG 35 kG 3 5 kG 30 0 390 kG 35 kG Getting to the field is part 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 UHS 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 usually round measure fields normal to their end They can also be used for
13. ed or abraded It may be tempting to choose a probe with the thinnest transverse stem or smallest diameter axial stem however it is always best to choose the most robust probe that fits the immediate application For example the HMMT 6J04 VR aluminum stem is less prone to damage than i the HMFT 3E03 VR flexible stem and the HMMA 2502 VR Gradient un 1 4 in diameter aluminum is more durable than the HMNA Probe selection would be easier if all fields were large and 1904 VR 3 16 in diameter fiberglass with its exposed Hall uniform but most fields ii limited in volume and contain sensor Note never fasten a probe stem to another object If a gradients changes in magnitude Hall effect probes measure probe is to be clamped always apply the clamp to the handle an average magnitude over their active area making it necessary to understand the relationship between active area and field gradients Please note Neither of these probe types are suitable for direct exposure to high voltage 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 probe tip and active area is specified for axial probes but is less easily defined for transverse probes 7 lll lL www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com
14. er of DSP technology is demonstrated in the superior performance of the Model 475 in DC RMS and Peak measurement modes DC Measurement Mode Field Uniformity Plot Across an Electromagnet Pole Face Static or slowly 2 3800 changing fields are measured in 2 3700 DC mode where the accuracy 2 3600 resolution and stability of the Model 475 are 2 3500 Field Tesla most evident 2 3400 In this mode the gaussmeter 2 3300 takes advantage 1 2 3200 of the internal im p p A l 7 E auto zero function and probe linearity compensation to provide its best accuracy Measurement resolution is enhanced by advanced signal processing capability allowing users the choice of high reading rates to 100 readings per second or high resolution to 534 digits The Model 475 also features front end amplification specifically designed to complement DSP data acquisition providing high stability and repeatability That along with probe temperature compensation makes the Model 475 the most stable gaussmeter ever produced by Lake Shore suiting it perfectly for demanding DC measurement applications such as field mapping and field control X Position mm www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com RMS Measurement Mode Selective Bandpass Filters 4 of a possible 15 Periodic AC fields are measured in RMS mode which Advanced Features The Model 475 combines ha
15. eral Ambient temperature 15 C to 35 C at rated accuracy 5 C to 40 C with reduced accuracy Power requirement 100 120 220 and 240 VAC 4 596 1096 50 Hz or 60 Hz 20 W Size 217 mm W x 90 mm H x 317 mm D half rack 8 5 x 3 5 x 12 5 in Weight 3 kg 6 6 Ib Probes amp Extensions Probe compatibility Full line of standard probes available custom probes also available not compatible with Model 450 421 probes Hall sensor compatibility Front panel programmable sen sitivity and serial number for user supplied Hall sensor Extension cable compatibility Probe extension cables with EEPROM available from 25 ft to 100 ft extension cables can be matched to probes in the field Lake Shore calibrated extension cables maintain the same accuracy as the Model 475 probe The uncalibrated version involves the operator loading the matching probe data file into the cable PROM directly from the Model 475 front panel Additional errors caused by the uncalibrated extension cables are 0 1 of field reading error and 1 C temperature reading error Model 475 gaussmeter user manual 4005 1 m 3 3 ft long IEEE 488 GPIB computer interface cable assembly includes extender required for simultaneous use of IEEE cable and auxiliary 1 0 connector RM Rack mount kit for one 1 rack gaussmeter in 483 mm 19 in rack RM 2 Rack mount kit for two 2 rack gaussmeter in 483 mm 19 in rack HMCBL 6 HMPEC 10 HMPEC 10 U HMP
16. ext four pages are provided to help you make an informed probe choice If you have additional questions contact Lake Shore and our experts can guide you through the selection process Field measurement application is the controlling factor in probe selection Probe characteristics along with the parameters described below should be considered when selecting a probe Magnitude Typical Hall effect probes cover an operating range of 4 to 5 orders of magnitude Operation beyond this field range requires some compromise in performance often including higher noise or loss of resolution Choosing the correct probe type ensures optimal performance in the desired measurement range High Stability HST 1 and HST 2 With a high field range of up to 350 kG 35 T high stability probes are used when fields exceed the limit of other probe types Their low field performance is slightly degraded with a minimum sensitivity of 50 mG 5 uT HST probes are also inherently more temperature stable than other probes and should be used when large temperature fluctuations are expected They are offered in a variety of stem geometries 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 At low fields their sensitivity can be as low as 5 mG 0 5 uT Convenient for many applications because of their relatively small a
17. initiate the data log sequence A TTL level hardware trigger out indicates when the instrument completes a reading and can be used to synchronize other instruments in the system An IEEE 488 software based trigger can be used like the hardware trigger in The Probe Connection The Model 475 is only half of the magnetic field 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 see page 6 3 OM www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com Measurement Features The Model 475 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 rel
18. ion of the physical properties of materials in temperature and magnetic environments
19. l 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 wideband AC mode the signal can be viewed on an oscilloscope to observe the shape of AC fields In peak mode the output 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 Line Input Assembly Serial I O DTE Probe Input Auxiliary l O IEEE 488 Interface 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
20. obe 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 BEEN a www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com Frequency Display When operating in RMS mode the gaussmeter can display the frequency of the measured AC field along with a field reading up to 20 kHz 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 necessary Keeping probes and their extensions from getting mixed up can become a problem when more than one probe is in use The Model 475 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 en
21. of active volume Frequency Probe type Corrected Operating Temperature Temperature range accuracy temperature coefficient coefficient of reading range maximum maximum zero Calibration 0 25 in 0 03 in 0 5 in 2 2 in 5 7 in DC to 400 Hz UHS 0 5 t0 2G 0 C to 75 C 1 mG C 0 02 C Small variations in or low values of large volume Application is optimum when fields are homogeneous When ordering a gamma probe a 4065 zero gauss magnetic fields such as that of the earth or fringe over lengths greater than 1 ft The active sensing chamber is suggested The standard 4060 zero fields around large solenoids can be measured length of the gamma probe is approximately 3 125 in gauss chamber is too small for the gamma probe with these ultra high sensitivity probes Resolutions of several gammas 10 G to tens of gammas are available www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com Instrument Specifications General Measurement Does not include probe error unless otherwise specified Input type Single Hall effect sensor Probe features Linearity Compensation Temperature Compensation AC RMS Measurement Auto Probe Zero and Hot Swap Measurement features Auto Range Max Min Hold Relative Mode and Frequency Connector 15 pin D style DC Measurement Probe Type 074 igit 454 digit 3 digit Ranges Resolution Resolution Resolution HST Probe 350 kG
22. operated manually Connector In 25 pin 1 0 connector Voltage output 1 Configuration Real time analog voltage output of wide band AC signal Range 3 5 V Scale 3 5 V FS on selected range Frequency response 1 Hz to 40 kHz wide band AC Accuracy Probe dependent Noise 1 0 mV Minimum load resistance 1 kQ short circuit protected Connector In 25 pin I O connector Voltage Output 2 Configuration Voltage output of field value generated by DAC Range 5 V Scale 3 5 V FS on selected range Resolution 16 bit 0 15 mV Update Rate 40 000 updates per s Accuracy 10 mV Noise 0 3 mV Minimum load resistance 1 kQ short circuit protected Connector In 25 pin I O connector Voltage Output 3 Configuration Voltage output of compensated DC or RMS field value generated by DAC also used for field control Range 10 V Scale User specified defaults same as Voltage Output 2 Resolution 16 bit 0 3 mV Update rate 30 updates per s Accuracy 2 5 mV Noise 0 3 mV Minimum load resistance 1 KQ short circuit protected Connector In 25 pin 1 0 connector Ordering Information Part Number Description 475 Model 475 DSP gaussmeter Please indicate your power cord configuration 100 VAC U S power cord 120 VAC U S power cord 220 VAC European power cord 240 VAC European power cord Accessories Included 106 253 I O mating connector 4060 Zero gauss chamber MAN 475 Accessories Available Gen
23. rdware and iso firmware elements to create advanced highlights the features that facilitate automation uniquely flexible and materials analysis filter functions of the Model 475 An overall frequency range of 1 Hz to 50 kHz is offered by the gaussmeter Selectable band pass and low pass filters allow users Frequency Hz to reject unwanted signals and improve measurement performance The exclusive Lake Shore Digital Signal Processing algorithms also free the Model 475 from the limitations of conventional RMS conversion hardware and provide better dynamic range resolution and frequency response than ever before These improvements permit meaningful RMS field measurements with broad frequency content or in noisy environments Field Control A built in PI control algorithm turns the Model 475 into an essential building block for magnetic field control in electromagnet systems It along with a voltage programmable magnet power supply is all that is needed to control stable magnetic fields in an electromagnet at the user specified setpoint One of the built in analog voltage outputs drives the program input of the power supply for either bipolar or unipolar operation Magnitude High Speed Data Transfer Peak Measurement Mode Magnetizing Pulse with 20 us Width The IEEE 488 interface can be set to Pulsed fields are measured in send readings in binary format rather Peak than the more common
24. solution Indicated by number of digits in above table 55 digit 4 digit 3 digit Resolution Resolution Resolution 3 dB bandwidth 1 Hz 10 Hz 100 Hz Time constant 1s 0 15 0 01 s Maximum reading rate 10 rdg s 30 rdg s 100 to 1000 rdg s 1mited feature set interface dependent DC accuracy 0 05 of reading x 0 00596 of range DC temperature coefficient 0 01 of reading 0 003 of range C 10 Peak Measurement Probe Type 434 digit Ranges Resolution HST Probe 350 kG 000 01 kG 35 kG 00 001 kG 3 5 kG 0 0002 kG 350 G 000 02 G 39G 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 30G 0 0020 G UHS Probe 39 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 table Max reading rate periodic mode 30 rdgs s 100 to 1000 rdgs s limited feature set interface dependent Peak accuracy 2 of reading 20 us or longer Peak frequency range periodic mode 50 Hz to 5 kHz Peak frequency range pulse mode 5 Hz to 50 kHz rM www lakeshore com Lake Shore Cryotronics Inc 614 891 2244 fax 614 818 1600 e mail sales lakeshore com 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 rdgs s Display
25. sure proper mating Hall Effect Generators Magnetic Field Sensor The Model 475 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 MCBL 6 blank connector to provide all gaussmeter functions except field and temperature compensation If no sensitivity information is available the Model 475 reverts to resistance measurement Display and Intertace Features Display The Model 475 has a two line by 20 character vacuum fluorescent display During normal operation the display is used to report field readings 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 four 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 The display configured to show the field control setpoint and current field value when field control is active Keypad The instrument has a 22 position keypad with individua
Download Pdf Manuals
Related Search