Pressure Gauge Controller - Model NGC2D USER MANUAL
Contents
1. seeseesoesoeseesessessossoesossesseesorsorsossessesseseeseeesosseesesseseeseeesesseseesseseessossessesseseeese Fan SOW eM ee E E E E N EE E T TOMDA UE a E saunas E A ee NTO FASSION EAE aeei E vce eevee cesaeeceotcestetveneee OFO Ce a A E E I E E E E ee eee ee Password FOGOL gupen E E lon Gauge COMMECHIONS sssecachetsccsecvsseegsessducesvoasecssanssscieceicssabesabacedeavsesvacaune EOST EE EE STT EEr NENOS PeO T Comte rer ern tee meen er vet Tee Tren Appendix A US PGI S aoa E A case os causnaessese teas vances ouput ee ere ee Page 1 Introduction The NGC2D process controller is a high accuracy Bayard Alpert BA ion gauge controller that offers integrated pressure measurement and process control The controller operates from electrical supply voltages in the range 100 to 240 volts and frequencies of 48 or 65 Hertz The controller may be used with UHV ion gauges incorporating tungsten or coated iridium filaments The controller can operate two ion gauges sequentially two AML Pirani gauges and one capacitance manometer Four power relays for process control are provided as is an internal thermocouple amplifier for bakeout control Automatic control of a titanium sublimation pump controller is also featured 1 1 Scope of this manual This manual provides installation operation and maintenance instructions for the Arun Microelectronics Ltd lon Gauge Controller model NGC2D Please read this manual before attempting to install and oper2. Arun Microelectronics Ltd 2015 All rights reserved TSP Ti Sublimation Pump Define whether you require multiple display and audible warnings of an impending TSP firing The first warning occurs 8 minutes before firing Define whether you require the opportunity to inhibit TSP firing during the countdown Timing of TSP firings is according to a fixed table of current pressure against the elapsed time since the last firing Relay C is energised for 0 5 seconds to fire the TSP The first firing will occur 10 minutes after the pressure indication falls below 1e 6mBar or 10 minutes after Starting emission if the pressure is already below 1e 6mBar and thereafter according to the table Pressure 1x10 1x10 1x10 lt 1x10 9 mBar Torr 6 to 7 7 to 8 8 to 9 Interval 10hours Degas The settings for degas parameters should not be changed until manual degas has been run see section 9 and settings appropriate for your chamber and usage have been derived Quick Degas Set the maximum power used in quick degas Programmed Degas Set the maximum power used in programmed degas the rate of power increase and the dwell time once maximum power is reached Page 11 7 Operation 7 1 Use of the Function Switch in the operating positions The Function Switch must be stationary for a brief time before any action results This allows you to rotate the switch through various operating positions without starting the ion gauge o
3. Change the set pressure with a or Y and confirm with ENT Define Autostart Yes or No Autostart starts the ion gauge the first time Pirani 1 pressure falls below the set pressure The set pressure is the same for both functions If they are used together Interlock is suspended until the lon Gauge has started Gauges Select the filament in use for each lon Gauge Change of the filament in use is allowed without entering the password if set Define the filament material type for each gauge This automatically sets the current limits for the filaments Use the Iridium setting for thoria or Yttria coated Iridium filaments Set the ion gauge overpressure trips OVP to suit the filament material and your customary practice The OVP will automatically restrict the maximum trip pressure of any relay assigned to that gauge to half the OVP A maximum OVP of 1e 3 mB Torr is recommended for an AlG17G with Tungsten filaments or 1e2 mB Torr with coated filaments Define whether you require the instrument to change emission current automatically If set to No the instrument will suggest when a manual change in emission current is appropriate Refer to section 8 2 for lon Gauge emission details Define whether you wish to add ion current to the Gauges Display Sequence lon current in Amps will be displayed following numeric ion gauge pressure Pirani Gauges can be switched on or off Switching off suspends the operation of the
4. Gauge operation Only press one switch at a time f C o1 06 ee 9 a 6 5 3 o F RIA i ns AIVIL reee ol RLC waw arunmicro com k O kaada I a an JU m PS s ga i ea 2 4 Ww y 7 6 5 4 3 2 2 NGC2D URV PRESSURE GAUGE CONTROLLER The messages and displays shown in the large display window are largely self explanatory and may be accompanied by sounds The legends above and below the display window indicate the units and the exponent scale for interpreting the bargraph displays of lon Gauge pressure a eo ian LEDs indicate the status of OS ao a en ee a O a the four relays available for NGC2D UHV PRESSURE GAUGE CONTROLLER pressure related control Bake and TSP control Each LED illuminates when the associated relay is The units of the pressure display are indicated by one of three energised LEDs in the display area The centre orange LED indicates that mBar has been selected the green LED above it indicates Pascal and the green LED below indicates Torr Arun Microelectronics Ltd 2015 All rights reserved Page Setup New users should explore and familiarise themselves with the use of the controls and displays before connecting any gauges or wiring to the rear panel 6 1 Switching on Turn the Function Switch to the OFF position Connect and switch on the mains supply and wait for the start up messages to run approx 5 seconds During this time both fans are checked for correct operation The last
5. Pirani Autostart and Interlock functions Page 9 Arun Microelectronics Ltd 2015 All rights reserved Gauges Cont Define whether you have a Capacitance Manometer CM connected Change the full scale pressure with A or W and confirm with ENT The full scale pressure and units of the CM are as defined by the manufacturer for 10v output The units of display are chosen independently under PASSWORD UNITS Select Yes to change the default gauge labels Each gauge can have a user defined three character gauge label Select each gauge in turn and change each character with A or and confirm with ENT Relay Assignment You can assign any relay to any gauge or to None Relays assigned to None are permanently de energised Trip levels are set to maximum on assignment Trip levels for relays are set using the TRIPS push button and can be modified when the Function Switch is at position IG1 OFF or IG2 Refer to section 7 2 for instructions on trip settings Relay C can also be assigned to trigger the TSP and Relay D to Bake Bake Set the bake temperature setpoint 50 250 C total bake time 1Hr to 90Hrs and overpressure setpoint as required During Bake relay D is energised when both the temperature and pressure are below their setpoints The hysteresis on temperature is 5C and on pressure is 50 Refer to section 10 for more information Page 10
6. The orientation of the gauge head should be such that the filament is to the side of or below the grid structure This will ensure that if the filament should sag or break it will not short circuit to the grid The gauge and controller are protected from all normal failure modes of either Users should be aware of potential hazards from other equipment particularly those introducing high voltages into the vacuum chamber Arun Microelectronics Ltd 2015 All rights reserved Page 6 5 Front panel BAKE SETUP DEGAS PASSWORD UNITS IG2 The rotary Function Switch has two sets of positions for setup a and operating The SETUP locations are labelled in orange ii print The switch must be stationary for a brief time before any DEGAS action results INTERLOCK AUTOSTART GAUGES RELAY ASSIGNMENT BAKE TSP DEGAS A set of status LEDs are situated in the Status Window The LEDs on the right side of the window show further information about operations involving the lon Gauges such as the Degas program in use The LEDs on the left side indicate the status of the instrument the fans and the number of the filament and gauge in use Flashing of the display or of individual LEDs either require a response by the user or indicate an error fault condition INC DEC and ENT are pushbutton switches with tactile feedback They select the E format of pressure display modify setups and change parameters before and during lon
7. display in the sequence will show Pirani 1 pressure or capacitance manometer pressure if enabled Pirani gauges take some time to stabilise before they indicate correct pressure If Pirani 1 is not connected the display will show PG1 gt 200mB If the Function Switch is at a position calling for emission at switch on emission is inhibited and Switch Em Off is displayed 6 2 Setup General description Setups are distributed among six switch locations in order to reduce the time taken to modify parameters There is no restriction on when how many times or in what order you can enter a particular setup You may move the Function Switch part way though a sequence if you do not wish to modify subsequent settings within a setup E g in SETUP GAUGES you may change the filament in use without progressing through filament material overpressure etc If the instrument is waiting for a response from you then part of the display will flash indicating that a choice can be made or a setting edited a and modify the choice or setting and ENT confirms it If you do not modify the displayed setting for a few minutes the instrument will beep periodically If you do not respond for a further few seconds then the current display will be replaced by Setup Aborted and the setting or choice at the aborted stage will revert to its former setting If you move the Function Switch after modifying a choice or value but have not confirmed it with E
8. electrical and electronic equipment Product Pressure Gauge Controller NGC2D Standards Harmonised and international national standards and specifications EN 61010 1 2001 Safety requirements for electrical equipment for measurement control and laboratory use EN 61326 1 2006 Electrical equipment for measurement control and Class B Emissions laboratory use EMC requirements Signature f Mr P Brooker Managing Director Date December 2007
9. ion gauge cable must be connected to the instrument ground stud lon gauge leads should not be installed close to cables carrying high a lon Gauge Connector Pin Allocations alternating currents or through areas where there are significant alternating magnetic fields They should be constrained since Function movement or vibration will generate charges or currents and these may disturb UHV pressure readings Third party ion gauge cables may not allow compliance with EU EMC Directives and may lead to unstable emission As a minimum there must be an overall screen on the lead and an inner screen on the collector connected to the BNC shell These screens must not connect either to the vacuum chamber or to each other Interlock pins 1 amp 3 must be connected together Pirani 1 amp 2 AML Pirani gauges PVU or PVB are suitable for use with this instrument Pirani 1 pressure is used for lon Gauge 1 Interlock and Autostart functions and should be installed in the same chamber as the lon Gauge Pirani 2 is normally used for backing line pressure measurement Arun Microelectronics Ltd 2015 All rights reserved Page 5 Relays Four single pole change over relays are provided for process control and can be independently assigned to any gauge Contacts are rated at 5A 240V maximum The contacts of the relays are shown diagrammatically on the rear panel legend in the de energised condition adjacent to the terminal blocks to which they
10. status gt Request a report of operating status for all gauges e g S0 lt Gauge on gt Switch on ion gauge emission n 0 5mA n 1 SmA e g i00 lt Select IG gt j n 1 lon Gauge 1 selected n lon Gauge 2 selected lt Gauge off gt Switch off ion gauge e g 00 lt override gt Permanently energise relay R R A to D e g O0A lt inhibit gt Permanently de energise relay R R A toD e g IOA lt bake gt n n 1 Start bake cycle n 0 Stop bake cycle Arun Microelectronics Ltd 2015 All rights reserved Page 20 2 7 lt status gt Status report The status report gives the operating status and pressure of each gauge in the NGC2 State byte As detailed above Error byte Relay status byte The relay status byte is of the form 0100XXXX2 where the least significant 4 bits indicate the state of relays A to D 1 energised with relay A indicated by the least significant bit An unused byte 0 Gauge record For each gauge in the NGC2 Header byte 2 Gauge type lon gauge Pirani capacitance manometer lon Gauge 1 3 Gauge number Pirani 1 Pirani 2 Capacitance manometer lon Gauge 2 4 Gauge status All bits are set to 0 unless stated otherwise lon Gauge Status Bit 0 gauge in emission Bit 1 O Bit 2 gauge controlling bakeout Bit 3 gauge in degas Bit 4 O Bit 5 filament 2 Bit 6 1 Pirani Gauge Status Bit 0 gauge
11. the instrument off and wait for the temperature to fall before re starting 15 3 Emission Fault lon gauge faults can have multiple causes some of which are transient or simultaneous The most common causes of persistent problems in emission are unsuitable gauges or leads or incorrect installation Other possible Causes e Excess emission current may be caused by a grid to filament short production of a plasma in degas or another source of ions or electrons nearby e Low emission current may be caused by a grid to ground short magnetic or electric fields an unsuitable filament loss of filament coating or incorrect setup of filament type e When using Yttria filaments If the filament worked previously the coating may have deteriorated If the filament has been exposed to air it will have adsorbed moisture attempt emission several times to drive it off Unsuitable or contaminated filaments operated at high local pressure may also cause this display Failure of Pirani gauge 1 will stop the ion gauge operating if the interlock is set regardless of any other conditions Operation of the ion gauge can be restored after failure of Pirani 1 if it is safe to do so by switching the Pirani gauges off and disabling Interlock and Autostart if appropriate 15 4 IGFilO C If IG fil x o c IG filament open circuit is shown the filament has probably failed or there is a poor connection to the cable In some cases if there is a high resistan
12. NT then the existing choice or value is unchanged If you do not require the Bake or TSP functions they can be disabled by not assigning relays to them Setups and access to operating parameters and functions can be password protected to prevent unauthorised se Cc Password Units Set Password Press a or Y to select if a password is to be used Press ENT to confirm If a password is to be used Change each character with a or v and confirm with ENT Select the units of pressure display mBar Pa or Torr The current selection will flash in the main display Press A or W to select 1 or 2 decimal place ion gauge pressure display Select if gauge pressures greater than 1mB should be displayed in scientific notation or decimal notation Select Yes to assign a 3 7 character instrument ID Change each character with a or v and confirm with ENT If enabled this ID will be shown during start up and is available as an item in the main display sequence Arun Microelectronics Ltd 2015 All rights reserved Page 8 Arun Microelectronics Ltd 2015 All rights reserved Select your preferred baud rate 9600 is the default for all AML software Select Yes and confirm to return the instrument to its factory default settings All user settings will be lost Interlock Autostart Define Interlock Yes or No Interlock prevents the ion gauge operating when Pirani 1 pressure is above a set pressure
13. ON On 0 5m com2 v 9 8E 11 mBar Request Data V Continuous Data On Sm ER an POED open Pirani 1 Relays off Energise 1E 03 mBar Hel Perey el Seer De Energise Prani 2 eje el mj Le 1E 03 mBar Bienes Stus VOZI Dn Dn Dn Dn s Capacitance Manometer m B ar Error Status lon Gauge Status Overemission 0K Overpressure OK Degas OFF A Filament K Pirani No Bake OFF ae Interlock Bake open circuit Filament Emission ON Temp 1023C Underemission OK tesi lo K IG Present OK Bake Status OK External INO Over Error OK Interlock NO temperature OK Start Bake Stop Bake Pirani 1 Open OK Pirani 2 Open OK Information Circuit Circuit Received 1023C Note lon gauge two decimal place pressure display is not compatible with this software Arun Microelectronics Ltd 2015 All rights reserved Page 18 15 Remote operation NGC2D Pressure Gauge Controller Interface Manual Issue 2 0 1 INTRODUCTION The serial interface is RS232 compatible and only one instrument may be connected to a computer serial port At switch on the NGCZ2D is reset into the local operation mode with the ion gauge switched off The NGC2D does not check the viability or consistency of commands issued by a remote computer 2 INTERFACE PROTOCOL 1200 2400 4800 or 9600 default baud 8 data bits 1 stop bit no parity no handshaking 2 1 Local remote control An NGC2D starts operation in local control i e using the fr
14. The programmed instrument ID is displayed if selected in PASSWORD UNITS Page 13 ee lon gauge operation 8 1 Display sequence when ion gauges are in emission In emission the LEDs in the Status Window show the ion gauge in use the emission current and the number of the filament in use Arun Microelectronics Ltd 2015 All rights reserved Starting the lon Gauge Turning the function switch to IG1 or IG2 always starts emission at 0 5mA Until the filament reaches emission temperature the display shows the emission current If there is an Interlock or an Autostart pending or any fault that prevents emission from starting an appropriate warning will be displayed The initial display of pressure is in numeric format Subsequent pressing of the a pushbutton will cycle through the Pirani amp Capacitance Manometer pressure displays the leak detector and IG Sensitivity lon gauge pressure can also be displayed in single decade auto ranging bar graph or full range bar graph formats These can be invoked by pressing the a pushbutton Manual Emission Change The Emission current can be changed manually when an ion gauge is in operation if Auto Emission is set to No in SETUP GAUGES See section 8 2 WARNING Changing emission current to 5 0mA at inappropriate vacuum levels could damage the lon Gauge filaments To change emission current manually press ENT An analogous display is shown to decrease emission cur
15. am or quick modes the grid power is increased automatically Use Manual Degas to derive safe rates of power increase and maximum power to set up the other modes in SETUP DEGAS Once UHV has been established most systems will only require an occasional Quick Degas Manual Degas In manual mode the degas grid power is increased by 2 5watts every time ais pressed If ais pressed several times the instrument stores up to five steps and increases power at five second intervals This is not recommended If a request to increase cannot be implemented or stored a sound is made The maximum degas power is 30 watts and the maximum degas time is 10 minutes The degas power is shown at the centre of the display The time on the right of the display is in minutes and seconds In manual mode this is the time elapsed since the start of degas in other modes it is the time remaining until completion of degas Pressing v in manual mode decreases the grid power by 2 5watts immediately After 10 minutes of manual degas Degas Finished is displayed Turn the Function Switch to OFF Programmed Degas Programmed Degas follows the profile set in SETUP DEGAS and is intended for gentler degassing over longer periods during pump down of a vacuum system Quick Degas Quick Degas increases the power rapidly to the level set in SETUP DEGAS and holds it for one minute If a fault occurs during degas Degas Aborted is displayed Arun Microel
16. are connected Inductive loads including contactor coils should have snubber networks connected in parallel to avoid arc generation which could interfere with the operation of this and other equipment The external wiring is connected to the instrument through a two part pluggable terminal block This can be removed and wired independently of the instrument Ensure that external wiring is of adequate cross section for the load current Strip and twist the wires do not tin them and poke into the receptacle in the terminal block Close the leaf on the wire by tightening the screw immediately above Take appropriate action to strain relieve the wiring nearby and to restrict access to the terminals if harmful voltages are to be present Fit the terminal block cover supplied If the Bake function is to be used then relay D must be assigned to Bake It is used to switch on the Bake heaters when energised Do not connect heaters directly to relay D use a contactor and fit a snubber directly across its coil The pressure measurement during the bake cycle is read from lon Gauge 1 only If the TSP function is to be used then relay C must be assigned to TSP Relay C is energised for 0 5 seconds to fire the TSP Consult the TSP manual for further information The pressure measurement for TSP control is read from lon Gauge 1 only Bake Thermocouple The K thermocouple tip must be isolated from the vacuum chamber and situated where it accurately represen
17. ate the controller This manual contains essential safety information which supplements the safety features of the controller Safety procedures are highlighted as WARNING instructions by the symbol below Failure to observe the instructions could result in injury or death to persons 2 Technical data 2 1 Mechanical Data Dimensions 19 full width rack Height 1U Depth 270mm excluding connectors Weight 2 7kg 2 2 Electrical Supply Supply Voltage 100 to 240 Volts nominal at 48 to 65 Hertz auto adjusting Power Consumption Less than 20 Watts idling Less than 75 Watts in emission Fuse 2 0 A T 5x20mm Supply socket IEC 320 C14 2 3 Environment Operating temperature Storage temperature Relative Humidity non condensing Maximum operating altitude Pollution category EN61010 Arun Microelectronics Ltd 2015 All rights reserved 5 to 35 C for specified performance Operation is inhibited at greater than 40 C 10 C to 70 C 10 to 90 2000 m 1 Page 2 2 4 2 5 2 6 2 7 2 8 2 9 2 10 Arun Microelectronics Ltd 2015 All rights reserved Electrometer Logarithmic conformance Slope temperature compensation Sensitivity adjustment lon Gauge Suitable type Range Grid Filament Collector Emission current Pirani Gauge Suitable type Range Capacitance manometer Suitable type Process trips Relays Assignment Bake out Thermocouple type Programme Communications Interfa
18. ce Settings lt 1 within any decade from 0 1 mA to 10 pA lt 5 to 1 mA and lt 20 to 2 pA at 25 C incoming air temperature lt 0 02 per degree Celsius 1 mbar to 140 mbar UHV Bayard Alpert gauges 1 x 10 3 to below 3 x 10 11 mbar Dependant on gauge head 200 V d c 500 V at 60mA in Degas Tungsten lt 12 V at lt 4 2A Coated iridium lt 12 V at lt 2 6A Filament power limited to gt 30 Watts Filament bias 50 V O V virtual earth Soft start emission control at 0 5mA or 5mA Constant voltage half bridge Calibration at connector 1 x 10 3 mbar to 200mbar Self powered with 10 V full scale output 1 10 100 or 1000 mbar or Torr Four x single pole change over 5 A at 240 V maximum Independently assignable to any gauge Mineral insulated K type with miniature flat pin connector Settable bake temperature 50 250 C bake time 1Hr to 9OHrs and overpressure limit RS232C 1200 2400 4800 or 9600 Default baud 8 data bits 1 stop bit no parity no handshaking Page 3 3 Warnings and safety WARNING Safe operation of ion gauges requires grounding of all exposed conductors of the vacuum system gauges and controller LETHAL VOLTAGES may be established under some operating conditions unless correct grounding is provided All exposed and isolated metal parts should therefore be reliably grounded to a common system earth point via 4mm or thicker copper wire braid the integrity of which should be c
19. ce connection or the cable is long or of inadequate cross section this fault may be reported after some period of normal operation Disconnect the mains power connector before checking any cables 15 5 Password forgotten To recover from a forgotten password the instrument will need to be reset to factory defaults This will return all parameters to their default state so all user settings must be re entered Turn the function switch to the Password Units position then press and hold the ENT button while turning the function switch back to the OFF position until the factory reset option is shown Arun Microelectronics Ltd 2015 All rights reserved Page 22 15 6 lon gauge connections AIGLX Lead Connections AlG17G Base Connections Interlock Grid Filament 2 4 ai Filament Ps Filament Common i Common Filament 2 Filament 1 Filament 1 Base connections of AlG1x gauges Connections at the controller end of an AIGLx lead If you probe the pins with an ohmmeter take care The cold filament resistance is very low The grid not to stress them as this may cause a leak collector and filaments should be isolated from each other and from the chamber 17 Assistance In the first instance contact the distributor or supplier of the equipment Always quote the serial number of the instrument and the version number of the program Provide a written description of the problem If the problem i
20. ch are commonly used in vacuum systems into the lon Gauge may damage the instrument Such damage is not covered by the warranty Discharge damage will be minimised by decreasing the impedance of the strap cable from the earth stud on the instrument to the vacuum system earth distribution point This connection may also be essential for operator safety follow the safety instructions and recommendations of the supplier of any high voltage equipment used in the vacuum system 4 Installation Checks on receipt of the instrument On receipt of the instrument remove all packing material and check that all items on the shipping list have been received Report any damage or shortages to the Company or the Distributor who supplied the instrument The packing material has been specially designed to protect the instrument and should be retained for possible future use 4 1 Instrument installation Mounting The instrument is suitable for mounting in a standard 19 rack and occupies 1U 1 75 44 5mm of the rack The mounting holes in the front panel are intended for retaining the instrument in the rack and will not support its weight Additional support is required toward the rear and various arrangements are provided by rack manufacturers for this purpose Arun Microelectronics Ltd 2015 All rights reserved Page 4 Ventilation The instrument is forced air ventilated through grilles on the sides and a vent in the rear panel Mount it ina location
21. decrease emission current is set to occur at plus half a decade in mB to ensure a consistent amount of hysteresis between the two thresholds 8 3 Prompted emission change If Auto Em is disabled in SETUP GAUGES the instrument will suggest when a change in emission current is appropriate This display is shown periodically when the collector Poser cP Bink birl current is below 100pA Pressing ENT while it is present cancels the display but does not change emission In order to change emission press A to change No to Yes and then press ENT The filament takes a second to Stabilise at the new emission temperature Analogous displays suggest when emission should be decreased If ENT is pressed when No is selected this display will not be shown again this cycle 9 Degassing Read this entire section before attempting degas Degas is required in UHV systems periodically It is not desirable to degas at high vacuum and above as this could damage the gauge or affect other operations in the vacuum chamber Degas increases the emission current and grid voltage so that the grid is heated to drive off adsorbed gas The degas power should be increased slowly to allow the gas evolved to be pumped away If power is increased too rapidly plasma will be produced which will short the grid to the filament or ground The instrument will detect this and degas will be aborted to protect the gauge and instrument The inst
22. e represents pressure over the range of 0 5 millibar to about 1x10E 3 millibar The lower pressure limit is determined by the heat loss due to radiation becoming significant compared to that due to thermal conductivity The radiant heat loss depends on the emissivity of the filament A new filament is bright but can become blackened by deposits from decomposed rotary pump oils and the lower limit of pressure readings will rise It is possible to clean filaments A 3 CAPACITANCE MANOMETERS Capacitance manometers operate by measuring the deflection of a thin circular radially tensioned membrane between the vacuum space and a reference volume at a pressure substantially below the operating range of the transducer The deflection is measured as a modulation of the electrical capacitance between the membrane and a fixed plate and converted to a voltage proportional to the pressure difference across the membrane Arun Microelectronics Ltd 2015 All rights reserved Page 24 Arun Microelectronics Ltd Fitzalan Road Arundel BN18 9JS United Kingdom Www arunmicro com PUTT EC Declaration of Conformity We Arun Microelectronics Ltd hereby certify and declare under our sole responsibility that the equipment mentioned below complies with the essential requirements and provisions of the EMC Directive 2004 108 EC the Low Voltage Directive 2006 95 EC and with Directive 2011 65 EU on the restriction of the use of certain hazardous substances in
23. eae 2 ARUN MICROELECTRONICS LTD Pressure Gauge Controller Model NGC2D USER MANUAL ISSUE 2 1 For use with program version 6 1 x Section RRO wu AR BP WN N N AAN Ww N gt 90 o0 WN Oo 10 11 12 13 14 15 16 15 1 15 2 15 3 15 4 15 6 17 Introduction BEER EERE RRR RRR RRR PER EEES EE EEIE ESETE EEIE RRR RRR RRR RRR RRR eee eee eee ge SOP OF INS E E cueexe ssa veces sees sastests eueyaedevs cues dasssvessoesaes caves sane cies ese eens Technical Data EERE RRR RRR R RRR RR RRR RRR RRR RRR RRR RR RRR RRR RRR RRR RR RRR RRR RRR Warnings amp SATCLY pcostin Installation ee ee ee ee EEEE EELEE EE EE EEEE EE ee ee ee EL EEL HS NCI meneen eE E A baw E E E E EE ELEA lOM GAUDE saar ENAN ee sos stews drs atk ANAE ARSENA POON PAN a eres nreemendana cu aepenmenseneneiaviesnneiaens Ca OCOD aroen oR E AA E T EE EEE A T E O U E r ee eee Pree eee Passwords a 07 came en PRO NE eS eee EPR ner eee ee ODEIO Ieeen tener an cre ce Ne N EAA mr many res marine Tt Te renner re On ofr Function SWITCH ICODEL SCION rosee a A A A eae nueaeeaaetn Relay TIP LEVELS arinina A OAE O A OT OEE EEA O EORR l DIPA CAUSE aA A A PIAM aeran R E sts LEAK DOLOCLOT sirnani TE A E tec es O e OVI T E N E WINS UE soio a T T E E TEA etme tee ee ee Capacitance Manometer lt acacscesesszcvanecorenecesucnatnspsiucencebene occeeasQendesibesavanccdnesveciewa diencseixueawoasessunaedasantve ts tetavinadineesdertemaeen
24. ectronics Ltd 2015 All rights reserved Page 16 10 Bake Baking is necessary for ultra high vacuum systems to reach their ultimate pressure Typically the complete vacuum system will be heated to 200 C and maintained at that temperature for at least 24 hours In addition to a temperature set point there is a pressure set point so that if excessive gas is evolved the heaters are switched off to avoid overloading the pumps As there are risks involved systems should only be baked after they have been pumped close to the best vacuum they can achieve without baking Bake should be competently supervised Setting the password will enable only operators who know the password to initiate or terminate bake The pressure should be significantly lower than the bake pressure set point before starting a bake as there will be a significant pressure rise as the system heats Arun Microelectronics Ltd 2015 All rights reserved Start Bake by turning the Function Switch to BAKE and press ENT Relay D must be assigned to the bake function it is used to switch on the heaters via a contactor If relay D is not so assigned the display will prompt you to re assign relay D If the password is enabled you are required to enter it If the entered password fails three times Bake Denied is displayed The bake program operates with the pressure from lon Gauge 1 only If all conditions are satisfied the lon Gauge starts emission and then Bake sta
25. evel is set at the upper limit of its range the relay is permanently de energised If a trip level is set at the lower limit of its range the relay is permanently energised Setting trip levels at these limits does not cancel the assignment of the relay Relays assigned to None are de energised The maximum setting for any relay assigned to the lon Gauge is half the overpressure trip setting Changing the overpressure trip may cause the status of relays assigned to the lon Gauge to change if the current pressure is between the former and new overpressure after emission is re started Numeric values of trip levels will change automatically if the units of measurement are changed in order to maintain the trip levels at the same pressures Arun Microelectronics Ltd 2015 All rights reserved Page 12 7 3 Display sequence when the function switch is in the OFF position The following displays can be selected sequentially by pressing INC or DEC Arun Microelectronics Ltd 2015 All rights reserved Pirani Pirani 1 pressure with falling pressure trend indicator The Pirani gauge low resolution bar graphs are also permanently displayed whenever the Pirani gauges are operating gt 200mB is displayed if the Pirani pressure is above its upper limit or disconnected Capacitance Manometer Capacitance Manometer pressure is only available in numeric format and only if the gauge has been setup IG Sensitivity lon Gauge sensi
26. hecked regularly No ferrite components should be installed High voltages are present within the instrument when operating and for some seconds after switching off Remove the mains lead before removing the cover for any reason Ensure that maintenance is carried out only by suitably trained personnel Instruments are shipped with password protection disabled If you set a password you must record what it is Password usage restricts access to most functions of the instrument other than pressure measurement The conditions set at manufacture assume that you do not require any interlocks and that the ion gauge has a Tungsten filament You may fuse coated lon Gauge filaments if you do not set up the instrument appropriately Allow several minutes for Pirani gauges to reach operating temperature after switching on before using them for interlock autostart or process control Two fans are used sequentially for cooling Orange Status LEDs on the front panel indicate which fan is being used If a fan fails a message is displayed at the time of failure and the LED for that fan flashes thereafter Operation with only one fan is permissible but replace a failed fan as soon as possible If the remaining fan fails operation of the ion gauge will be disabled Replacement fans must conform to the specification printed on the rear panel and are available from AML Discharges from X ray power supplies and other high voltage and high energy sources whi
27. ionised by the collision and those within the grid volume are attracted to the collector to form a current which is proportional to the concentration of gas molecules over a very wide range Pressure may be derived from the ion current by solving the equation lon current Pressure S sresgeceeseeeccesecdee sees eo anseee Sensitivity x Emission Current where the units for the two currents are the same and the sensitivity is a quoted constant for a particular gaugehead and gas species The impact of electrons on the grid structure generates soft X rays some of these impinge on the collector and release photo electrons These form a small current in the same direction as the ion current When this photocurrent becomes significant in relation to the true ion current the gauge ceases to function as a reliable pressure transducer and is said to have reached its X Ray limit A 2 PIRANI GAUGES The Pirani Gauge is a thermal conductivity gauge A tungsten filament in the vacuum space is heated from a constant voltage source and is incorporated in a Wheatstone bridge The electrical resistance of the filament depends on its temperature and this in turn depends on the rate at which heat is conducted away from the filament by residual gas The thermal conductivity of a gas depends on its pressure below about 1 millibar and the nature of the residual gas The Pirani gauge unbalances the Wheatstone bridge and the voltage across the bridg
28. ont panel In local mode the NGC2D responds only to commands without parameters lt poll gt lt control gt lt status gt and lt reset error gt The lt control gt command puts the NGC2D into remote mode and all the other commands can then be used The front panel can still be used to change the display but not to control gauges or change set points When a host takes control of the NGC2D emission is stopped and any current Setup operation is cancelled When the host returns the NGC2D to local control emission is again stopped The host must terminate any running bake cycle before returning the NGC2D to local control If any relay is permanently Energised or De energised while in remote control the setpoint for that relay is changed to the limit so the status of the relay is no longer affected by pressure either in remote control or on return to local control 2 2 Host Computer Commands The host computer sends commands in the following format First byte ASCII 47 Second byte Command character All commands are represented by a single character Third byte Ignored on NGC2D Character 0 to 8 or X ASCII 88 This ensures compatibility with PGC1 which had a multi drop capability where instruments were addressable All the examples below use 0 Optional parameter Additional command parameters single ASCII characters 2 3 NGC2D Response The instrument responds with a state byte and an error byte follo
29. operating 5 Gauge error lon Gauge error Bit 0 filament open circuit Bit 1 overemission Bit 2 underemission Bit 3 overpressure Bit 4 Pirani interlock autostart prevents starting Bit 6 1 Bit 7 Filament leads Pirani Gauge error Bit 0 Pirani gauge open circuit Bit 6 1 Bit 7 0 6 13 16 17 CR LF Pressure Comma delimited string in scientific notation e g 1 3E 07 If the gauge is not operating the string consists of spaces only Bake Temperature Three bytes of temperature followed by C CR LF All pressure values read from the NGC2 are in the NGC2 s current display units Arun Microelectronics Ltd 2015 All rights reserved Page 21 16 Troubleshooting 15 1 Fan slow failed Fans are used alternately on a periodic cycle A fan that is running slowly will cause an occasional Fan 1 slow or Fan 2 slow message to be displayed during its cycle Fan speed is dependent on environmental factors and a warning may not be present in every cycle for a marginal fan Fans reported as failed may still be working but are too slow to be effective If a fan is reported as slow ensure that you have a replacement ready Replace a failed fan as soon as convenient Instructions are packed with spare fans 15 2 Temperature If the ambient temperature exceeds 40 C the ion gauge is automatically switched off to protect the instrument and a temperature warning will be displayed in place of the pressure reading Turn
30. ply will be required The CM can be interrogated by pressing a Display switch until the CM pressure reading appears This is only available in numeric format Ensure the full scale and pressure selected in CM setup matches your gauge 12 Recorder Output An analog voltage representing the base 10 logarithm of collector current is available on the auxiliary connector This is scaled at 1V per decade and 0 volts represents 1E 13A The output increases by 1volt when emission is increased from 0 5 to 5mA The output resistance is padded to 1Kilohm As the recorder output is related to collector current it has to be combined with sensitivity and emission current to derive pressure Pressure antilog V 13 s le where V is the recorder output voltage s is the sensitivity and le is the emission current in amps 13 External inhibit Operation of the ion gauge may be inhibited by an external contact closure which prevents starting of the ion gauge by any means External inhibit can be used as an external trigger for the ion gauge The condition specified by the position of the emission switch will be established when the external inhibit is released 14 Windows Software Windows software to demonstrate the NGC2D s interfacing features is available to download from AML s website in Documents Software E AML NGC2 Demonstration Program V0 7 o amp es Pressures Controls ETETEN E ERT ComPort lon Gauge Remote Local
31. r other functions The ion gauge will be started about one second after rotating it to the IG position As additional security Bake or Degas will not start unless you enter the password if set and then select and or confirm your requirement 7 2 Relay trip levels Relay trip levels can be reviewed and modified in the IG1 OFF and IG2 positions of the Function Switch by pressing ENT when a pressure reading is being displayed If a password has been set you must enter it to be able to modify settings If the password is set and you do not enter it you may view the settings but cannot change them If you make no response at any stage of the sequence the display times out to the pressure display that was current before the start of the sequence and the setting at the interrupted stage is unchanged The relay trip levels or their assignments to Bake TSP are displayed in sequence starting with Relay A and progressing to Relay D The next in the sequence is shown each time that you press ENT The status LED for the relay and the numeric setting of the trip level flash if trip modification is allowed Modify the displayed setting by pressing a or v then press ENT to confirm it and display the next Relays assigned to a gauge are energised when the pressure falls below the Low setpoint and de energised when the pressure rises above the High setpoint The minimum allowed hysteresis is 10 of the low setpoint If a trip l
32. rent Page 14 8 2 Changing ion gauge emission For most practical purposes the default emission current of 0 5mA is satisfactory and desirable This is because the performance of the electrometer is much better than that of older instruments and there are disadvantages to changing the emission current Increasing emission will give a pressure burst and the recorder output will also be shifted by 1volt either of which may be problematic Because the filament is permanently hotter at 5mA emission the indicated pressure will normally be slightly above that at 0 5mA after the burst subsides At extreme UHV a higher emission current may be desired If Auto Em is set to Yes in SETUP GAUGES then the instrument will change emission current automatically when appropriate If Auto Em is set to No the instrument will suggest when a manual change in emission current is appropriate It is not necessary to increase emission current le until the collector current Ic is less than 100pA The pressure P corresponding to these currents is dependent on the sensitivity s according to P Ic s le If the collector current falls below 1pA Low lon C will be displayed instead of the pressure display to indicate the instrument is beyond its usable range for the set emission current If the pressure burst produced after an increase in emission lasts for more than a few minutes then degassing of the lon Gauge may be required The set point to
33. rts The progress of Bake is shown as a percentage of total time in the bar graph to the top left of the pressure reading The ON OFF status of the heater is shown below this bar graph The Bake LED in the Status Window flashes during Bake Pressing and holding the ENT button will display the elapsed time and heater status When Bake is finished you can leave the function switch on BAKE to monitor the temperature and pressure as the system cools Moving the Function Switch off the BAKE position alone cannot terminate a bake cycle If you do this you will be asked to return it to BAKE and then to confirm whether you want to terminate the bake If the password is enabled you will then be required to enter it This procedure discourages an inadvertent termination of a bake If Bake is terminated manually it can be resumed by pressing the ENT button Bake will be terminated automatically if a gauge fails or the pressure exceeds the ion gauge overpressure limit or if the thermocouple measuring the temperature fails or is disconnected The display will show the cause of the termination alternating with bake duration remaining Page 17 11 Capacitance manometer The capacitance manometer CM is connected via the Auxiliary Connector For details on this connector refer to Section 4 1 The instrument caters for capacitance manometers with full scale output voltages of 10v representing 1 10 100 or 1000 millibar or Torr An external power sup
34. rument only allows degas to start e When a valid password has been entered If password use is enabled e f the gauge has run in emission for at least 5 continuous minutes in the preceding 30 minutes If any condition prevents degas starting then Degas Denied will be displayed Move the Function Switch to OFF Arun Microelectronics Ltd 2015 All rights reserved Page 15 If the ion gauge is in emission when degas is selected emission will not be interrupted unless degas is denied and degas will seamlessly start when the mode has been selected If the ion gauge is not in emission when degas is selected emission is run automatically at 0 5mA and then 5mA for a few seconds before degas power is applied A fixed degas overpressure trip 1e 5mBar is active for a few seconds at 5mA Degas is aborted if the pressure exceeds that level In all modes degas power is changed in 2 5 watt steps In Program and Quick modes the pressure can continue to be read during degas by returning the Function Switch to the corresponding IG position If the Function Switch is left in the IG position when degas finishes normal emission will resume seamlessly If the Function Switch is left in the DEGAS position when degas finishes emission will cease Relay operations are suspended during degas Move the Function Switch to the DEGAS position to select the required mode Select Manual Program or Quick with a or v and confirm by pressing ENT In progr
35. s lon Gauge Operation eeseeseeseesoesesseeseseesseseesosssesseseeseesoesseseeseeseesoesorseeseesoesersorsossessessoesessess Display Sequence in Emission essessesseeseecsesossoesoesoeeseesoesoroesoessessoesorsorsoesersersersoeseeseesoeeorsorsoesersorsoesoeesessersessoroeesersersesses SAUN RV O G UOS aaa E A E E ETE AEAEE AETA Emission CHANGE guceessersiecsossucdesacssecss ucvscaivestessuadesyvebedecewisieauiasaessadaesseinesuseethcesvaagucouseieuseausvasecagtsyatteanduccsataeeesenneaneanexviaein Changine Emission GUIPOIE sescccroses tvesvcectaeatencecascveansusrssvecaosusacesqavessectuasnanscoesaeseuaeaaucsnsavenverseuouayccemeaueatiaavanseeabinasesteasuaess Prompled Emission CHang sccicccescescsestincccgasuuccssesnesesasecasaacesese ses dann E E ATETEA ET cece andes DAS T E A A R Mantal ssisereri nese oen E A EEEE E E E E Ponram aeos E E A RA E O T S QUICK eb eeaeee Eere EEEE EEE E ce cca cen E EEA EAEE E AEEA EEEE OERE BOKO a creck hci E EE E AE EEE Eia Capacitance Manometer sesessssesesesesesessososesesosesesessosososeseseosoessosososescsesesesessosesesesesesesessese RECO ODU anae EARR 401g 1M LLL 8h iien me rntett cnr teen yeas erin a lerT ert mavrr enna re mmc rr er tT Windows Software sssssssssssossosooeseoeseecccsssseeeesssssssssssssssssssooososeoccccocceeeseeesessssssssssssssssssososoosose l Remote Operati h sosorsccseonsseaiin oann a A ele esas een ets Troubleshooting
36. s related to gauges and leads quote the serial numbers and filament type used Do not return products to AML without prior approval Arun Microelectronics Ltd Fitzalan Road Arundel WesBN18 9JS England Tel 44 0 1903 884141 email info arunmicro com www arunmicro com legislation designed to prevent the disposal of such waste and to encourage proper treatment measures to minimize the amount of waste ultimately disposed to landfill To view AML s WEEE policy please visit www arunmicro com gt Servicing gt WEEE Policy b In the European Union EU waste from electrical and electronic equipment WEEE is now subject to Arun Microelectronics Ltd 2015 All rights reserved Page 23 APPENDIX A Gauge Principles A 1 IONISATION GAUGES lonisation gauges are thermionic triode devices The appropriate choice for UHV use is the Bayard Alpert type This consists of a very thin collector wire mounted along the axis of a cylindrical mesh grid The filament is outside the grid and usually parallel to it The grid is voltage biased positively with respect to the filament and the collector negatively A stabilised emission current is established between the incandescent filament and the grid structure Electrons oscillate on long paths through the open grid structure being repelled from the central collector and attracted to the grid A proportion of the electrons encounter gas molecules before reaching the grid These molecules are
37. tivity can be modified by pressing ENT then a or v to change the number and then ENT again to confirm the new setting The units of sensitivity are the reciprocal of the units of pressure display you have setup and are dependent on the gauge in use and the gas species For nitrogen and carbon monoxide the sensitivity for AML AlG17G gauges is 19mB 26Torr or 0 19Pa If the units of measurement are changed the numeric value of sensitivity is changed to make the pressure readings consistent Leak Detector The leak detector operates on the lon Gauge pressure if the lon gauge is in emission otherwise it operates on Pirani 1 pressure The display is a histogram of the rate of pressure change with baseline restoration and is accompanied by a tone whose frequency is modulated by the offset of the histogram Use a probe gas e g helium or volatile blocking agent e g acetone at the suspected leak site If a pressure change is produced there may be a leak Allow the baseline restoration to restore the histogram and tone close to the centre before continuing probing Pressing ENT will change the sensitivity of the leak detector The height of the pair of dots to the right of Leak in the display indicates the sensitivity Three levels of sensitivity are provided for the lon Gauge and two for Pirani 1 Temperature The ambient temperature inside the instrument near the electrometer is monitored and may be displayed Instrument ID
38. ts the bake temperature Mineral insulated thermocouples with a miniature flat pin thermocouple connector should be used Auxiliary Connector The Auxiliary AUX connector terminal block is plug in with pin assignments indicated on the rear panel legend The Capacitance Manometer output is connected to CM and OV Refer to section 12 The recorder is connected between REC and OV Refer to section 13 Connecting ILOCK to OV will prevent ion gauge emission Refer to section 14 Serial Connector The serial interface is RS232 compatible and only one instrument may PAARE eecee min ilee taleas be connected to each computer serial port A USB to RS232 serial adaptor may be required Function The connector is a 9 way D type female connector The pin numbering has been chosen so that a 9 way straight through male to female cable will be satisfactory for use with a PC serial port 4 2 lon gaugehead installation Consult the information supplied with the gauge head for advice on flanges gaskets and adaptors for mechanical fixing Mount the gauge head in a position where the free electrons generated in its vicinity will not affect other equipment The performance of the ion gauge may be affected by other electron or ion generating processes within the vacuum chamber should shielding of the gauge head be necessary ensure that the conductance between the gauge head and volume of interest is not significantly decreased by its presence
39. wed by a CR LF ASCII 13 10 If a status report was requested the state and error bytes are followed by the report and CR LF All responses terminate in CR LF 2 4 Timing of Next Command The host computer should not begin transmitting a new command until a CR LF has been received signalling the end of transmission It is not necessary to poll the NGC more than 4 times per second and we strongly recommend that a delay of at least 100ms is implemented before the next report request The response to commands is typically less than 1 second 2 5 State amp Error byte coding State byte Bits 3 0 Instrument type 00102 NGC2D Arun Microelectronics Ltd 2015 All rights reserved Page 19 Bit4 0 local mode 1 remote mode Bit5 1 Bit6 0 IG 1 selected 1 IG 2 selected Bit7 lon gauge disconnected Error byte BitO gauge specific error Bit1 over temperature trip Bit2 bake error Bit3 temperature warning Bit4 0 Bit5 0 Bit6 1 The value in the error byte is maintained until reset by a lt reset error gt command 2 6 Host Computer Command Characters Command parameters are single printable ASCII characters Relays are addressed by uppercase letters A to D lt poll gt Poll instrument returns state and error byte e g PO lt control gt C Remotely control NGC2 e g CO lt release gt Return NGC2 to local control e g RO lt reset error gt Reset all error flags e g EO lt
40. where there is an adequate supply of air as close as possible to cool room ambient temperature The instrument is tolerant of and is compensated for operation at elevated ambient temperatures up to 40 Celsius Long term accuracy and reliability will be enhanced by operation at the lowest possible temperature If there are other instruments in the rack which generate significant amounts of waste heat try to ensure that this is deflected away from this instrument Line Power Connection The NGC2D operates from a 100V to 240V nominal AC power source having a line frequency of 48 to 65 Hz Use a three wire power cord to connect to a properly grounded wall outlet Line Fuse There is a line fuse located on the inside of the instrument on the rear of the power inlet connector A spare fuse is located in a replacement fuse holder on the circuit board Replacement fuses must be T2 0A High voltages are present within the instrument when operating and for some seconds after switching off Remove the mains lead before removing the cover for any reason Grounding The instrument earth stud must be connected directly to the vacuum system earth distribution point with a low impedance strap cable gt 4mm 2 or 12awg there must be no ferrite components installed on it we fied n ma iao m p i a Mle i W j n Stictentse nome AIAI INT lon Gauge 1 amp 2 Use AML approved gauges with properly screened leads The ground braid of the
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