Teledyne DNV-33D User's Manual
Contents
1. TELEDYNE HASTINGS INSTRUMENTS HASTINGS MODEL DNV 33D VACUUM GAUGE HASTINGS MODEL ONV 330 I VACUUM GAUGE MWe TELEDYNE INSTRUMENTS ISO 9001 f A Hastings Instruments KEMA CERT 10192 01 ATeledyne Technologies Company DO Accredited by the Dutch f Cound for Accreditation RvA A Accredited by the Registrar Accreditation Board RAB Manud Print History T he print history shown below lists the printing dates of all revisions and addenda created for this manual T he revision level letter increases alphabetically as the manual undergoes subse quent updates Addenda which are released between revisions contain important change information that the user should incorporate immediately into the manual Addenda are num bered sequentially W hen a new revision is created all addenda associated with the previous revision of the manual are incorporated into the new revision of the manual Each new revision includes a revised copy of this print history page Revision A Document N umber 156 122000 seeeemmeHHH ene D ecember 2000 Revision B Document N umber 156 082005 oonccconnnocccinnnnnnncinananacinan ocn nonanonanananoss August 2005 Visit www teledyne hi com for WEEE disposal guidance H astings Instruments reserves the right to change or modify the design of its equipment without any obligation to provide notification of change or intent to change Table of Contents 1 0 2 0 21 2 2 232. DNV 33D Cast DIMENSION euren ee Front Panel 96mm SQ Depth 10 354 Gatge Tube A DV 33D 1 DV 33D 2 DV 33D 3 G ge EIN Welded stainless steel shell PS SITE C A o E E A EEEE 1500 PSIG max Panel Cut oUt seiors anena 3 1 16 77 5 mm H x 3 5 8 92mm W Rane agra ce weap cee a eles E E E E AOS E AA 1 1000 mTorr Readout OMIT c REES Digital Meter lU RT O TT 115 VAC less than 6 watts CIL M Linear 0 1 VDC analog 4 ma Max Eo A 5 Es aiai A E EE aieas Calibrated for air or nitrogen Dash number Defines System Fitting Differences 1 Weld Fitting 2 Cajon SS 4 VCR Male Gland 3 Cajon SS 4 VCR Female Gland page 7 page 8 2 0 INSTALLATION QUICK START Install DV 33D gauge tube in vacuum system see section 2 4 Ensure system is leak free Connect the tube to the DN V 33D power supply display and apply 115 VAC Allow 30 minutes for warm up see section 3 1 Set the switch on the DN V 33D to the OPR position for normal operation factory calibration Set the switch on the DN V 33D to the Set A position T he relay will now be energized when the pressure is less than the set point T he set point LED will be on when the relay is energized T he set point may be set by adjusting the appro priate potentiometer on the front panel Set the switch on the D N V 33D to the Set B position T herelay will now be energized when the pressure is less than the
3. 2 4 3 0 3 1 3 2 4 0 4 1 4 2 4 2 1 4 2 2 4 2 3 5 0 5 1 5 2 5 3 5 4 5 5 6 0 GENERAL DESCRIPTION 2 5 OPERATION PRINCIPLE isis since 7 SPECIFICATION Sora 7 INSTALLATION PROCEDURE u a 8 Panel M o ntind ii dd aia 8 G augeTube Connections nennen nennen A EE eaa 8 Connection of Relay Contacts and Output Terminals eseese 8 G ugeT ubelnstallation u rere ig ERE RR EY SERE RR DR ERE ERR Ei 8 OPERATION OF VACUUM GAUGE vssocicisrninancianiaienicn cid 9 Powering of Vacuum Gauge uir tenen ee e ed 9 SWiItON POSICION sartsa TT 9 CALIBRATION AND TROUBLESHOOTING GUIDE 9 Check of TUDeA CCU a cce ertt ae ada ra 9 DNVSS3 Calibracion 10 Reference Check uoce id ear os ER rd dee e olo Fa p ra e eo PH 10 R ecalibration for Length G augeT ube Cable sssseseeeees 10 Optimizing G augeT ube Accuracy iiciin aaa aAA a AE AE AARAA 10 NOTES ON VACUUM MEASUREMENT nm 10 Effects of CondensableVapors sssssssseeeeee eene nnns 10 A C EET 11 A erit m E b rers c ted ees 11 Effect of Thermal Conductivity ssssssseseeeneeenemeen ennemis 11 Effect of System Conductance esssersennnennnnneennnnnernnnnnennnnnnennnnnnnnn nennen nennen nen 15 WARRANTY 2 dede he 12 SECTION I General Description T he Hastings D igital Vacuum G auge M odel DN V 33D incorporates proven H astings thermo pile technology to producea linear vacuum gauge that covers the range of 1 1000 mTorr T he d
4. ally important when working with pressures of less than 10 mTorr where atmospheric gases are likely to flood the enclosure due to leaks Also if the system is being pumped continuously gauges spaced at different distances from the pump will register different pressures For a reliable comparison of different vacuum gauges it is necessary then to insure that the vacuum system be free of any outgasses or other sources of apparent leaks T his can best be determined by closing off the system from the pumps and observing if there is any rise in pressure within the range of interest 5 3 Ingassing Ingassing is an effect opposite to outgassing and may also lead to erroneous readings lonization gauges exhibit a kind of pumping action that tends to clean up residual gasses in certain ranges of pressure and thereby lower the pressure Also if a cold trap is in a closed system the total pressure may change considerable while condenseble vapors such as water carbon dioxide and mercury and being condensed 5 4 Effects of T hermal C onductivity All Hastings vacuum gauges are originally calibrated in dry air Since this calibration is a function of thermal conductivity any gas having a thermal conductivity different from that of air will also have a different calibration Contact factory for calibration in gases other than air 5 5 Effects of System Conductance Each element that makes up a vacuum system has associated with it a certain conductance t
5. e analog output will be over 2 volts and the display will read 1 T herelay will energize when the pressure is below thetrip points N ormal relay position is de energized ATM pressure side of set point 3 2 Switch Position OPR Normal operating position Display reads pressure Output on back panel reads 0 1 volt SET A SET B Displaysthetrip point of the appropriate relay If the pressure is below thetrip point the relay is energized and theL ED will belit T hetrip points can be set from 0 950 mTorr T herelay trip points are set by adjusting the appropriate pot located on the front panel CAL Used when zeroing the vacuum gauge tube at hard vacuum Adjust the Cal pot on the rear panel for 000 on the display Test A voltage is injected into the 2 stage AM P so that the GAIN of the gauge can be set on the average curve Adjust GAIN pot on rear panel for 400 on the display NOTE T he signal output will change when the switch is put in this position and the set points may trip See section 4 2 1 Reference C heck 40 CALIBRATION AND TROUBLESHOOTING GUIDE All Hastings vacuum gauges and tubes have been carefully checked and calibrated at the factory before shipment If a calibration check is desired the methods in the following sections may prove helpful 4 1 Check of TubeAccuracy T he simplest and quickest method of checking the operation and calibration of power supply display and gauge tube is to keep a n
6. eful property of responding to the total pressure of all gases and vapors that are present in the gauge tube To exclude vapors from a vacuum system it is necessary to employ a trap of some kind that will absorb or condense vapors Water vapor is by far the most common source of this difficulty A cold trap cooled by liquid nitrogen is an effective means in removing vapors It may be necessary to keep M cL eod gauges constently under vacuum for several hours or days with a trap before it will read correctly T he use of rubber or Tygon tubing connecting the gauge to the vacuum system can lead to gross errors due to excessive outgassing and or adsorbtion by thetube It is recommended that only glass or metal tubing be used Reference should be made to the instructions furnished by the manufacturer of the M cL eod gauge to be sure that it is provided with a suitable trap 5 2 Outgassing Hastings gauge tubes are fabricated from materials which have been proven by years of usage to be relatively free from outgassing H owever all surfaces of glass and metal that are exposed to the vacuum system may liberate gases and vapors that were previously adsorbed during expo sure to the atmosphere If the surfaces are contaminated with foreign matter this outgassing may be much more persistent than if the surfaces are clean T he possibility of outgassing must be considered in checking the accuracy of H astings gauges or in checking for leaks T his is especi
7. ew clean gauge tube on hand as a standard To check operation install both of the gauge tubes together in the same clean dry vacuum system and pump until a steady pressure is obtained Plug the gauge onto both tubes alternately and check reading Be sure to allow time for readings to settle If the tube reads a considerably higher pressure than the tube being used as a standard a calibration shift in the old tube has occured T his is most likely resulting from tube contamination T hetube calibration can possibley be restored by gently rinsing the interior of the tube with a solvent such as trichlorethylene After cleaning thoroughly dry the tube and degas it before reinstallation into a vacuum system T his is done to avoid system contamination by the solvent If calibration cannot be restored by this precedure replace the old tube with a new gauge tube CAUTION Do not attempt to measure the resistance of the gauge tube element while it is under vacuum Some ohmmeters apply measuring voltages sufficient to burn out the thermo pile while under vacuum T he resistance of the gauge tube can be measured safely at atmo spheric pressure T his measurement is made between pins 3 5 and 7 counting clockwise from the key looking at the base of the gauge tube A measuring device such astheT riple M odel 630 Test Set with ohms switch on the X 10 range is suitable for this purpose page 9 page 10 4 2DNV 33 Calibration All calibration voltage
8. ge tube down to hard vacuum Set the front panel switch to the CAL position Adjust the CAL potentiometer in the rear of the unit until the display reads 000 Pump the system to a known pressure using a reference in the system At this pressure adjust the gain potentiometer until the display reading matches the reference reading T he unit should now be calibrated Best average fit to the curve will occur if 700 mTorr is used for this setting D o not usethis instrument with another tube unless resetting the gain to 400 per 4 2 1 or performing the above procedure for the specific tube Notes on Vacuum Measurements 5 1 Effects of CondensableVapors If the readings of H astings gauges are to be compared with readings of other types of gauges consideration must be given to the possible effects of condensable vapors on other gauges For example none of the many types of M cL eod gauges give correct readings if condensable vapors such as water alcohol acetone etc are present in the gauge T he M cL eod gauge operates by compressing residual gases and vapors to obtain a reading and this compression will tend to compress vapors that are present T his usally results in pressure reading that is lower than the actual pressure Furthermore two different M cL eod gauges could be used and both may have different readings Both of these readings however could be incorrect if vapors are present Hastings thermopile gauges however have the us
9. hat is the opposite of resistance For example baffles connecting tubing and sharp turns may cause pressure drops throughout the system during pumping and during the time in which the System is reaching static equilibrium It is not an uncommen occurence to measure different pressures at different locations in a vacuum system In checking the calibration of a vacuum gauge care must be taken to insure that the gauge and the reference are at the same pressure page 11 SECTION 6 6 1Warranty Repair Policy Hastings Instruments warrants this product for a period of one year from the date of shipment to be free from defects in material and workmanship T his warranty does not apply to defects or failures resulting from unauthorized modification misuse or mishandling of the product T his warranty does not apply to batteries or other expendable parts nor to damage caused by leaking batteries or any similar occurrence T his warranty does not apply to any instrument which has had a tamper seal removed or broken T his warranty is in lieu of all other warranties expressed or implied including any implied warranty as to fitness for a particular use Hastings Instruments shall not be liable for any indirect or consequential damages Hastings Instruments will at its option repair replace or refund the selling price of the product if Hastings Instruments determines in good faith that it is defective in materials or workmanship during the war
10. igital display reads directly in mTorr T heinstrument provides an analog output signal which may be used to drive a remote indicator for recording data logging etc T he output is scale is 1 volt for 1000 mTorr TheDN V 33D also includes dual set points A set and B set with LED indicators located on the front panel R elay contacts are also provided for remote switching T he rear panel of the instrument provides access to terminal blocks for AC power cord gauge tube relays and analog output connections T he calibration adjustment potentiometers may also be accessed through the back panelof the unit T he instrument is factory calibrated on a stan dard average curve for D N V 33 vacuum gauges page 5 page 6 O perating Principle LO SECTION II T he operation of H astings vacuum gauges uses a patented noble metal thermopile circuit T he hot junctions of the thermopile are heated directly by an AC current while an equal number of cold junctions are kept at ambient temperature by heavy mounting studs T husa DC voltage is then generated between the hot and cold junctions As the pressure decreases the lowering of the thermal conductivity of the gas surrounding the hot junction tends to increase the tempera ture of the hot junctions thus increasing the output of the thermopile T his change in output is then amplified linearized and calibrated as a function of pressure SPECIFICATIONS Ihres Model M m
11. ranty period D efective instruments should be returned to H astings Instruments shipment prepaid together with a written statement of the problem and a Return M aterial Authorization RM A number Please consult the factory for your RM A number before returning any product for repair C ollect freight will not be accepted 2 Non Warranty Repair Policy Any product returned for a non warranty repair must be accompanied by a purchase order RM A form and a written description of the problem with the instrument If the repair cost is higher you will be contacted for authorization before we proceed with any repairs If you then choose not to havethe product repaired a minimum will be charged to cover the processing and inspection Please consult the factory for your RM A number before returning any product repair TELEDYNE HASTINGS INSTRUMENTS 804 NEWCOMBE AVENUE HAMPTON VIRGINIA 23669 U S A ATTENTION REPAIR DEPARTMENT TELEPHONE 757 723 6531 1 800 950 2468 FAX 757 723 3925 E MAIL hastings instrumentsOteledyne com INTERNET ADDRESS http www teledyne hi com Repair Forms may be obtained from the Information R equest section of the H astings Instruments web site page 12
12. s are factory set and will rarely change T he methods for checking gauge calibration are detailed below 4 2 1 Reference C heck TheDNV 33D incorporates a quick reference check reading To utilize this feature the front panel switch must be in theT EST position In this position the digital display should read 400 3 If it does not read this the calibration GAIN pot should be adjusted to bring the reading back to 400 T his will bring the gauge back on the standard average calibration curve NOTE T he signal output will change when the switch is put in this position and the set points may trip Pump the gauge tube down to hard vacuum Set the front panel switch to the CAL position Adjust the CAL pot in the rear of the unit for 000 on the display If there is a midscale refer ence available to the system see section 4 2 3 on recalibration Calibration is complete for use with the standard average curve 4 2 2 Recalibration for D ifferent Length G augeT ube C ables A maximum of 100 feet of gauge tube cable can be utilized by the D N V 33D If the cable length or size 18 gauge is changed the unit must be recalibrated T he procedure for recalibration is described in section 4 2 1 4 2 3 Optimizing G augeT ube Accuracy Individual tubes can be trimmed for best fit upscale on the curve by performing a calibration adjustment of the gain pot vs tube output against an accurate reference standard to do this Pump the gau
13. set point T he set point LED will be on when the relay is energized T he set point may be set by adjusting the appro priate potentiometer on the front panel Set the switch on the DN V 33D to the CAL position T his is to be used when zeroing the gauge with the tube at a pressure less than 0 1 mTorr Set the switch on the D N V 33D to the T EST position Usethis position to check the D N V 33D and to set the gain for individual tubes 2 1Panel M ounting TheDNV 33D instrument package can be mounted in a 3 1 16 inch high by 3 5 8 inches wide hole Secure the gauge with the mounting brackets provided 2 2 Connect the G augeT ube wire to the gauge as follows REAR PANEL GAUGETUBE WIRE COLOR TUBE PIN 2 3Connect other wires to relay contacts and output terminals 2 4G augeT ube Installation Install the gauge tube in a clean dry vacuum system with the open end pointing down so as to be self draining should any vapors condense within the tube SeeSec 5 1 For maximum accuracy it is recommended that the tube be outgassed in the vacuum system for a minimum of 4 hours 30 OPERATION OF VACUUM GAUGE 3 1 Powering of Vacuum G auge Plug the8 ft power cable into a single phase 115 VAC DN V 33D or 230VAC ENDV 33D line A line frequency of either 50 or 60 Hz is satisfactory Allow 30 40 minutes for warm up Plug the gauge tube cable onto the gauge tube W hen the tube is exposed to a pressure greater than1000 mTorr th
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