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Model 979 Series Helium Mass Spectrometer Leak Detector 

DRAFT 9/15/03

iii

Warranty

Products manufactured by Seller are warranted against defects in materials and workmanship for 
twelve (12) months from date of shipment thereof to Customer, and Seller’s liability under valid war-
ranty claims is limited, at the option of Seller, to repair, to replace, or refund of an equitable portion of 
the purchase price of the Product. Items expendable in normal use are not covered by this warranty. All 
warranty replacement or repair of parts shall be limited to equipment malfunctions which, in the sole 
opinion of Seller, are due or traceable to defects in original materials or workmanship. All obligations of 
Seller under this warranty shall cease in the event of abuse, accident, alteration, misuse, or neglect of 
the equipment. In-warranty repaired or replaced parts are warranted only for the remaining unexpired 
portion of the original warranty period applicable to the repaired or replaced parts. After expiration of 
the applicable warranty period, Customer shall be charged at the then current prices for parts, labor, 
and transportation.

Reasonable care must be used to avoid hazards. Seller expressly disclaims responsibility for loss or 
damage caused by use of its Products other than in accordance with proper operating procedures.

Except as stated herein, Seller makes no warranty, express or implied (either in fact or by operation of 
law), statutory or otherwise; and, except as stated herein, Seller shall have no liability under any war-
ranty, express or implied (either in fact or by operation of law), statutory or otherwise. Statements made 
by any person, including representatives of Seller, which are inconsistent or in conflict with the terms of 
this warranty shall not be binding upon Seller unless reduced to writing and approved by an officer of 
Seller.

Warranty Replacement and Adjustment

All claims under warranty must be made promptly after occurrence of circumstances giving rise thereto, 
and must be received within the applicable warranty period by Seller or its authorized representative. 
Such claims should include the Product serial number, the date of shipment, and a full description of 
the circumstances giving rise to the claim. Before any Products are returned for repair and/or adjust-
ment, written authorization from Seller or its authorized representative for the return and instructions as 
to how and where these Products should be returned must be obtained. Any Product returned to Seller 
for examination shall be prepaid via the means of transportation indicated as acceptable by Seller. 
Seller reserves the right to reject any warranty claim not promptly reported and any warranty claim on 
any item that has been altered or has been returned by non-acceptable means of transportation. When 
any Product is returned for examination and inspection, or for any other reason, Customer shall be 
responsible for all damage resulting from improper packing or handling, and for loss in transit, notwith-
standing any defect or non-conformity in the Product. In all cases, Seller has the sole responsibility for 
determining the cause and nature of failure, and Seller’s determination with regard thereto shall be 
final.

If it is found that Seller’s Product has been returned without cause and is still serviceable, Customer will 
be notified and the Product returned at its expense; in addition, a charge for testing and examination 
may be made on Products so returned.

Items Not Covered by the Warranty

Examples of items not normally covered under warranty include ion sources, TC gauges, O-rings, spec-
trometer tube cleaning and overhaul, mechanical pump oils, vacuum system overhauls, and obvious 
abuse or customer error. These items are considered normal maintenance for this type of equipment.

3/1/00

Summary of Contents for 979 Series

Page 1: ...D R A F T 9 1 5 0 3 OPERATIONS MANUAL vacuum technologies Model 979 Series Helium Mass Spectrometer Leak Detector Manual No 699909979 Revision K September 2003 ...

Page 2: ...Detector Contra Flow ConvecTorr and TriScroll are trademarks or registered trademarks of Vacuum Technologies Alconox is a registered trademark of Alconox Inc Apiezon is a registered trademark of M I Materials Ltd Loctite and PST are registered trademarks of Loctite Corporation Scotch Brite is a trademark of 3M ...

Page 3: ...duced to writing and approved by an officer of Seller Warranty Replacement and Adjustment All claims under warranty must be made promptly after occurrence of circumstances giving rise thereto and must be received within the applicable warranty period by Seller or its authorized representative Such claims should include the Product serial number the date of shipment and a full description of the ci...

Page 4: ...Model 979 Series Helium Mass Spectrometer Leak Detector This page intentionally left blank D R A F T 9 1 5 0 3 ...

Page 5: ...ction 1 Introduction to the Model 979 Series 1 1 1 1 The Model 979 1 1 1 1 1 Model 979 Series Configurations 1 1 1 2 Unpacking the 979 1 7 1 2 1 Unpacking Instructions 1 7 1 2 2 Removing the 979 from the Skid 1 8 1 2 3 Removing Loose Packing 1 8 1 3 Services Required for Operation 1 9 1 3 1 Power 1 9 1 3 2 Helium 1 10 1 3 3 Recommended Additional Services 1 10 1 4 Preparation for Operation 1 10 1 ...

Page 6: ...t Up 2 14 2 6 1 1 Selecting Internal or External Calibrated Leak for Calibration 2 15 2 6 1 2 Selecting Full or Fast Calibration Routine 2 15 2 6 2 Reject and Audio Set Points 2 16 2 6 2 1 Changing and Enabling Set Point Values 2 16 2 6 3 Auto Sequencer Set Up 2 17 2 6 3 1 Auto Sequencer Set Up Controls 2 18 2 6 4 Rough Pump Set Up 2 19 2 6 4 1 Selecting Rough Only or Split Flow Mode 2 19 2 6 4 2 ...

Page 7: ...libration 3 10 3 1 5 1 2 Atmospheric Calibration 3 11 3 1 5 2 Test Port Pressure Gauge Calibration Procedure 3 11 3 1 5 2 1 Vacuum Low Pressure Calibration 3 12 3 1 5 2 2 Atmospheric Calibration 3 12 Section 4 Maintenance 4 1 4 1 Daily Maintenance 4 4 4 1 1 Sensitivity Check 4 4 4 2 Recalibrate the Internal Calibrated Leak 4 4 4 3 Spectrometer Tube Overhaul 4 4 4 3 1 Removing the Spectrometer Tube...

Page 8: ...rminal B 4 Appendix C Introduction to Leak Detection C 1 C 1 Leak Testing Why is it Needed C 1 C 2 Classes of Leak Detection C 1 C 3 Terminology C 2 C 4 Various Methods of Testing for Leaks C 3 C 5 Helium Mass Spectrometer Leak Detection MSLD C 4 C 5 1 Principles of Mass Spectrometry C 4 C 5 2 Application as a Leak Detector C 4 C 5 3 The Nature of Flow in a Vacuum C 4 C 5 4 Facts About Leak Rates ...

Page 9: ...Screen 0 6E 09 atm cc sec 2 8 2 5 Bar Graph Display 0 6 x 10 09 atm cc sec 2 8 2 6 System Information Screen Typical Display 2 12 2 7 First Menu Selection Screen 2 14 2 8 Calibrated Leak Set Up Screen 2 14 2 9 Reject and Audio Set Points Screen 2 16 2 10 Auto Sequencer Set Up Screen 2 17 2 11 Rough Pump Set Up Screen 2 19 2 12 Leak Rate Ranging Set Up Screen 2 20 2 13 Output Control Set Up Screen ...

Page 10: ... Second Magnetic Pole Piece 4 17 4 20 Discolored Ground Slit Plate 4 17 4 21 Discolored Ground Magnet Pole Piece 4 18 4 22 VacuSolv Cleaning Wipe 4 18 4 23 Inspecting the O ring 4 19 4 24 Spectrometer Tube Reassembly 4 19 A 1 System Control and Communication Panel A 1 A 2 Optically Isolated Output Circuit Sketch A 2 A 3 Optically Isolated Input Circuit Sketch A 3 A 4 979 COM Cable Wiring Diagram A...

Page 11: ...ystem 3 7 3 2 979 Valve State Table Dual Mechanical Pump System 3 8 4 1 Scheduled Maintenance 4 3 4 2 As Required Maintenance 4 3 4 3 Tools and Parts Required for Spectrometer Tube Overhaul 4 5 4 4 979 Spare Parts 4 22 4 5 979 Accessory Item List 4 24 A 1 Summary Table of Optically Isolated Outputs A 2 A 2 Summary Table of Optically Isolated Inputs A 3 A 3 Summary Table of Non Isolated I O A 4 A 4...

Page 12: ...Model 979 Series Helium Mass Spectrometer Leak Detector This page intentionally left blank D R A F T 9 1 5 0 3 ...

Page 13: ...stimmt auquel se réfère cette déclaration est conforme à la auz norme s ou au x document s normatif s al que se refiere esta declaración es conforme a la s norma s u otro s documento s normativo s waamaar deze verklaring verwijst aan de volende norm en of richtlijn en beantwoodt a cui se rifersce questa dichiarazione è conforme alla e sequente I norma o documento I normativo i Frederick C Campbell...

Page 14: ...l hazards associated with this equip ment They must know how to recognize hazardous and potentially hazardous conditions and know how to avoid them The consequences of unskilled improper or careless opera tion of the equipment can be serious This product must only be operated and maintained by trained personnel Every operator or service person must read and thoroughly understand operation maintena...

Page 15: ...n a large well ventilated room Alcohol methanol or other solvents are irritants narcotics depressants and or carcinogens Their inhalation and or ingestion may produce serious side effects Prolonged or continued contact with the skin will result in absorption through the skin and moderate toxicity Always ensure that cleaning operations are carried out in large well ventilated rooms and wear eyeshie...

Page 16: ...toxic containment exhaust Exposure to hazardous gases could result in serious injury or death WARNING Equipment tightness is guaranteed for normal operating conditions when the equipment leaves the factory It is the user s responsibility to maintain the level of tightness particularly when pumping dangerous products CAUTION The performance and operating safety of this equipment can only be guarant...

Page 17: ...nty To avoid electric shock connect the product power cord to a grounded power receptacle A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation CAUTION Vacuum Technologies strongly recommends the use of surge protection to improve the immunity of the 979 Series leak detectors against unidirectional transients caused by the following phen...

Page 18: ...ical abuse All electrical connections must be performed by a qualified electrician and must comply with national and local codes Ensure that the electrical installation conforms with your local safety requirements Electrical installation must include the appropriate branch circuit at least 20 A with long time delay and reliable earth ground Do not use an extension cord Use only the power cord that...

Page 19: ...anel of the unit Operation of this equipment in a residential area is also likely to cause harmful radio communications interference in which case the user will be required to correct the interference at his own expense Vacuum Equipment and Cleanliness Cleanliness is vital when servicing the leak detector or any vacuum equipment There are some techniques that are more important in leak detector se...

Page 20: ...ter tube Do not use alcohol methanol or other solvents on O rings To do so causes deterioration and reduces their ability to hold a vacuum If applicable apply a small amount of Apiezon L grease and wipe the O rings shiny dry NOTE Due to the effective cleaning nature of VacuSolv solvent and its residue free properties Vacuum Technologies Component and Spectrometer Tube Cleaning Kit Part Number 6700...

Page 21: ...e to lose sensitivity WARNING Store the Ion Source in a cool dry area in a tightly sealed container Wash hands thoroughly after handling the Ion Source and especially before smoking or eating Gross Leak Option If the Gross Leak option is installed heed the following CAUTION Do not make any alterations to the Gross Leak Do not touch the knurled nut on the Gross Leak The Gross Leak is calibrated at ...

Page 22: ...oil WARNING To avoid injury wait until the turbo pump is completely stopped before disconnecting it from the vacuum system Vacuum Technologies Services The following are two of the many services that Vacuum Technologies offers its customers Please see our catalog or contact us to learn of the services that are available Contact Vacuum Technologies Customer Service at 1 800 8VARIAN for details Rebu...

Page 23: ...d mechanically pumped leak testing station on a cart Outline drawings for each configuration are shown in Section 1 1 1 Model 979 Series Configurations The 979 uses Vacuum Technologies Platform leak detector electronics architecture to oper ate the spectrometer assembly control the mechanical and high vacuum pumps control the valve block and provide leak rate and system status information to the o...

Page 24: ... T 9 1 5 0 3 Figure 1 2 shows the outline drawing and physical dimensions of a single oil sealed mechanically pumped leak testing station with the 979 Series Leak Detector on a two wheel cart Figure 1 2 Single Oil Sealed Mechanical Pump Configuration on Two Wheel Cart ...

Page 25: ...T 9 1 5 0 3 1 3 Figure 1 3 shows the outline drawing and physical dimensions of a single dry mechanically pumped leak testing station with the 979 Series Leak Detector mounted on a two wheel cart Figure 1 3 Single Dry Mechanical Pump Configuration on Two Wheel Cart ...

Page 26: ... R A F T 9 1 5 0 3 Figure 1 4 shows the outline drawing and physical dimensions of a single dry mechanically pumped leak testing station with the 979 Series Leak Detector on a four wheel cart Figure 1 4 Single Dry Mechanical Pump Configuration on Four Wheel Cart ...

Page 27: ...9 1 5 0 3 1 5 Figure 1 5 shows the outline drawing and physical dimensions of a dual oil sealed mechanically pumped leak testing station with the 979 Series Leak Detector on a four wheel cart Figure 1 5 Dual Oil Sealed Mechanical Pump Configuration on Four Wheel Cart ...

Page 28: ... D R A F T 9 1 5 0 3 Figure 1 6 shows the outline drawing and physical dimensions of a dual dry mechanically pumped leak testing station with the 979 Series Leak Detector on a four wheel cart Figure 1 6 Dual Dry Mechanical Pump Configuration on Four Wheel Cart ...

Page 29: ...ry power cords Pump manuals for the purchased configuration Any optional equipment ordered Any manuals for optional equipment purchased 1 2 1 Unpacking Instructions To unpack the 979 leak detector and remove it from the skid 1 Inspect the container for evidence of damage in shipment Do not discard any evidence of rough handling Report any damage to the carrier and to Vacuum Technologies Customer S...

Page 30: ...d the front of the skid 2 Lift the front end of the unit and gently lower it onto the floor 3 Lift the rear of the unit and roll it on the front casters until it is clear of the skid 4 Gently lower the rear end onto the floor Method 2 1 Using the brace removed in Step 6 of Section 1 2 1 Unpacking Instructions as a lever carefully raise the front edge of the skid between 1 and 2 2 While a helper ho...

Page 31: ...y II of the UL3101 1 Standard Fixed mains socket outlet shall be connected to PROTECTIVE EARTHING system For indoor use only Pollution Degree II in accordance with UL3101 1 Standard CAUTION Vacuum Technologies strongly recommends the use of surge protection to improve the immunity of the 979 Series leak detectors against unidirectional transients caused by the following phenomena Switching phenome...

Page 32: ...ated with oil causing slower pumping speeds and higher helium backgrounds in the leak detector The replacement time interval of the oil mist eliminator is determined by whether the user frequently operates at elevated roughing pressures pumps on large volumes or frequently cycles the system Refer to Section 4 6 979 Spare Parts List on page 4 22 and Section 4 7 979 Accessory Item List on page 4 24 ...

Page 33: ...entilation requirements for your specific application as discussed in Section 1 3 3 Recommended Additional Services on page 1 10 must also be provided at this point NOTE Refer to Section 1 5 1 Bench System Installations on page 1 11 for instructions on bench system installations which require some customer configuration 1 5 1 Bench System Installations Figure 1 7 represents the process for install...

Page 34: ...ondensing 20 C 4 F to 60 C 140 F ambient temperature 1 7 Front Panel Displays and Controls The 979 front panel leak rate display and control buttons are located on the front right hand side of the leak detector Figure 1 8 The panel features large color coded and clearly labeled buttons and a large easy to read bar graph display A brief description of the control buttons follows A more detailed dis...

Page 35: ...test states depending on the achievable test port pressures and leak rates The green LED above the button illumi nates when the 979 is in a test state When in TEST pressing the TEST HOLD button automatically advances the 979 to the HOLD state The yellow LED below the button illuminates when the 979 is in the HOLD state Zero The ZERO button is functional only in the test state The ZERO function zer...

Page 36: ...0 on page 3 3 The 979 does not display a leak rate while the UNDER light is on If this light stays on for more than a few seconds recalibrate the system to set operating parameters to the correct zero value This situation can take place if the 979 was not fully warmed up before calibration was initiated Over The OVER range light indicates that the system is saturated with helium and the measured l...

Page 37: ...pump configuration or the dedicated forepump of a dual pump configuration Remote Control Input A 9 pin female D type connector is provided to connect the optional remote control device Part Number L9558301 The operation procedure for the optional remote is outlined in the Remote Control Operation Manual Part Number 699909915 Control Logic Not currently used Sniffer Inlet Not currently used System ...

Page 38: ...tacle Forepump Power The 20 A forepump power output connector accepts the mating connector from the fore roughing pump of a single mechanical pump configuration or the mating connector from the dedicated forepump of a dual mechanical pump configuration Rough Pump Power The 20 A rough pump power output connector accepts the mating connector from the dedicated roughing pump of a dual mechanical pump...

Page 39: ...perator limited control of the 979 Series Leak Detector at a distance of up to 25 feet from the unit The Universal Remote is connected through the port labeled Varian Remote Control on the rear panel see Figure 1 9 on page 1 14 For operation instructions refer to the Universal Remote Instruction Manual provided with the remote Figure 1 11 Universal Remote Option ...

Page 40: ...0 10 5 x 10 11 Leak Units atm cc sec mbar l sec torr l sec Pa m3 sec Response Time Less than 0 5 second in accordance with AVS Standard 2 1 Amplifier Drift Less than 5 of full scale of the most sensitive range in accordance with AVS Standard 2 1 Noise Level Less than 5 of full scale peak to peak in accordance with AVS Standard 2 1 Calibration Fully automated tuning and calibration using the intern...

Page 41: ...nd Non isolated Analog output 0 10 V Non isolated Remote Control DB 9S interface Accessories optional Universal Remote part L9558301 with 25 foot cord External Calibrated Leak and Power Probe Recommended Operating Ambient Conditions Installation Indoor use only Altitude up to 2000 m 6 400 feet Installation Overvoltage Category II Pollution Degree II according to UL3101 1 Standard Temperature 12 C ...

Page 42: ... 1 1 to Figure 1 6 on page 1 6 Weight 50 lb 23 kg net stand alone bench mount unit 180 lb 82 kg net wet 1 pump 979 version with DS 302 oil sealed pump on a two wheel cart 243 lb 111 kg net wet 2 pump 979 version with DS 302 and SD 451 oil sealed pumps on a four wheel cart Table 1 1 979 Series Specifications Continued Specifications 979 Helium Mass Spectrometer Versions ...

Page 43: ...on on the front panel to place the system in test mode then pressing the CALIBRATE button on the front panel to perform an automated calibration of the system Calibration can be verified by pressing the READ STANDARD LEAK button on the front panel when in TEST mode Press the READ STANDARD LEAK button again to return to TEST mode If an external leak is to be used first press the VENT button to vent...

Page 44: ...nfiguration and set up and the achievable test port pressure and leak rate The TEST indicator LED located above TEST illuminates when the 979 is in a test state If the TEST HOLD button is pressed while the 979 is in the test state the unit advances to the HOLD state and the HOLD indicator LED located below HOLD illuminates When in HOLD mode the test port valve V6 is closed isolating the test port ...

Page 45: ...RD LEAK button is only functional while the leak detector is in a test state The READ STANDARD LEAK button activates the optional internal calibrated leak allowing verification of the system calibration When the system is in READ STANDARD LEAK mode its LED indicator lights Press the READ STANDARD LEAK button to isolate the test port from the system evacuate the calibrated leak manifold and expose ...

Page 46: ... through the entire bar graph scale The LOG mode display setting is often desirable in sniffer applications so the audio response corresponds directly to the size of the leak The SNIFFER ON OFF button is used to toggle the 979 leak detector in and out of SNIFFER mode The SNIFFER indicator LED illuminates when SNIFFER mode is enabled When the leak detector is in VENT mode press the SNIFFER ON OFF b...

Page 47: ...ntrols RUN SET UP or SERVICE Two different keys are provided with the leak detector Key T008 operates the switch in either the RUN or SET UP positions The T008 key is intended for use by a line supervisor or engineer and allows most parameters to be changed but does not allow any operation that could damage the unit Key T009 operates the switch in RUN SET UP or SERVICE positions The T009 key is in...

Page 48: ...n 2 4 979 Touch Panel Home Screen on page 2 8 Figure 2 2 979 Touch Panel Home Screen 2 3 1 Contrast Adjustment of the Touch Panel Display Press the upper left or right corner of the Touch Panel Home Screen to change the contrast 2 3 2 Changing Variables in Touch Panel Screens Touching the box that contains the variable to be changed causes the first digit of the variable to be highlighted To chang...

Page 49: ...t as indicated in step 2 NOTE Touching the ESC box before touching OK or BACK causes the selected parameter to revert to its previously stored value 2 3 3 Selecting Options in Touch Panel Screens Many parameters are set via toggle boxes that you touch to switch between values or modes For example Manual Range can be set to ON or OFF by touching the toggle box to switch between displaying ON and OF...

Page 50: ... screen correlates directly with the bar graph leak rate display Figure 2 5 The units for the measurements are user selectable from the Units Set Up screen see Section 2 7 1 Units Set Up on page 2 28 Figure 2 4 Leak Rate Displayed on Home Screen 0 6E 09 atm cc sec Figure 2 5 Bar Graph Display 0 6 x 10 09 atm cc sec Digital Leak Rate Display Test Port Pressure Leak Detector Status not shown Conditi...

Page 51: ...mal operating states are detailed in Table 2 2 on page 2 10 2 4 4 Leak Detector Condition The Leak Detector Condition not shown in Figure 2 4 is displayed below the Leak Detec tor Status and indicates the current condition of the leak detector Under normal operating conditions this line is blank The 979 leak detector conditions are detailed in Table 2 3 on page 2 10 2 4 5 Reject Status Indicator A...

Page 52: ...G Indicates that the leak detector is currently ROUGHING the test port and any attached test objects or fixturing attached to the test port STD LEAK Indicates that the optional internal calibrated leak standard valve opens and the leak detector is reading the leak value The leak detector reverts to HOLD mode while reading the internal leak standard VENTED Indicates that the test port is vented to ...

Page 53: ...ring the auto tuning routine OFFSET WAIT Indicates that the system is setting the OFFSET value REJECT Indicates a test object failure during an Auto Sequencer Test cycle See Section 2 6 3 Auto Sequencer Set Up on page 2 17 STABILIZATION WAIT Indicates that the system is waiting for the electronics to stabilize before completing the start up routine STD LEAK PREP Indicates that the optional interna...

Page 54: ...abeled BACK is located on the lower right hand of the System Info screen Touch this box to return to the 979 Home screen a Table 2 4 System Information Screen Conditions CONDITION DISPLAY DESCRIPTION AUDIO SET POINT AUDIO SET POINT ACTIVE Audio Set Point is active AUDIO SET POINT INACTIVE Audio Set Point is inactive AUTO SEQUENCER AUTO SEQUENCER ON Auto Sequencer automatic test cycle is enabled AU...

Page 55: ...System is set up so that the most sensitive leak rate range displayed is 10 EXP REJECT SET POINT REJECT 1 2 3 4 ACTIVE Reject set points displayed are active this line is blank when all set points are disabled or inactive ROUGH PUMP Dual pump configuration only ROUGH PUMP ROUGH ONLY Dedicated rough pump is connected to the test port only during the roughing cycle ROUGH PUMP SPLIT FLOW Dedicated ro...

Page 56: ...the Main Menu screen are described in this section Figure 2 7 First Menu Selection Screen 2 6 1 Calibrated Leak Set Up Touch the CAL LEAK SET UP box to display the Calibrated Leak Set Up screen shown in Figure 2 8 It is used to set the values of the Internal and External Calibrated leaks to select whether to use an internal or external calibrated leak standard for calibration and to select either ...

Page 57: ...scanning the ion source chamber voltage and the variable focus voltage optimizing each value for a maxi mum helium signal Once the tuning process is complete the sys tem gain is adjusted to bring the leak detector into calibration FAST CALIBRATION During fast calibration the leak detector compares the leak rate signal with the calibrated leak value and if the gain adjustment required to bring the ...

Page 58: ...ions port and upon inquiry through the RS 232 line see Appendix B Communications Protocol Disable individual reject set points using the ON OFF buttons located to the right of each set point field AUDIO SET POINT The AUDIO SET POINT control is used to activate the audio tone when the measured leak rate value exceeds the threshold value leak rate pass fail specification set by the operator When the...

Page 59: ... most stringent reject set point value A Pass condition is indicated by the system reverting to the VENT mode upon completion of the test cycle A Fail condition is indicated by the system reverting to the HOLD mode and all operating buttons being disabled except VENT A failed condition also results in REJECTED being displayed on the Home screen of the touch panel and a reject set point activation ...

Page 60: ...the typical time required to rough your test object to the tolerable test pressure Failure to achieve the tolerable test pres sure within the pre selected rough time is an indication of a gross leak in your test object or test fixturing or that time allowed was insufficient TEST TIME The TEST TIME variable determines the amount of time that the leak detector remains in test before it compares the ...

Page 61: ... the test object reaches the tolerable test transfer pressure the roughing valve closes and the dedicated rough pump is isolated from the test object SPLIT FLOW In SPLIT FLOW mode the dedicated rough pump continues to pump on the test object after the tolerable test transfer pressure has been achieved Split flow testing provides additional pumping capacity on the test object during the test cycle ...

Page 62: ...a system unintentionally The function status remains unchanged after a system power down The VENT LOCK function is inactive when the AUTO SEQUENCER feature is enabled Touch the VENT LOCK box to toggle the status to ON or OFF Touch DONE to return to the previous menu screen 2 6 5 Leak Rate Ranging Set Up Touch the LEAK RATE RANGING SET UP box to display the Leak Rate Ranging Set Up screen Figure 2 ...

Page 63: ...pecification is only in the 10 7 atm cc sec range then setting the range stop to 10 08 atm cc sec reduces the test cycle time by eliminating the need for the leak detector to reach its most sensitive scale during each test cycle To enable or disable RANGE STOP touch the ON or OFF box under the desired function MANUAL RANGE The MANUAL RANGE feature configures the 979 so that it only displays the pr...

Page 64: ...able 2 6 show sensitivity matrixes for performing Fine and Gross tests using standard and high sensitivity configurations High Sensitivity System The High Sensitivity 979 system can achieve 10 10 atm cc sec 5E 11 MDL sensitivity This sensitivity can be achieved at a transfer pressure of 100 mTorr High ambient helium background conditions may prevent 10 10 atm cc sec testing at relatively high pres...

Page 65: ... FLOW GL GROSS LEAK Table 2 6 979 High Sensitivity Leak Detector Test Fine Gross 2 Pump Range 10 9 8 7 6 5 4 3 2 Valve Path MS1 MS MS CF MS CF CF2 CF GL CF GL GL3 GL Transfer Pressure 1 Pump4 100 mTorr 100 mTorr 100 mTorr 5 Torr 100 mTorr 5 Torr 5 Torr 5 Torr Transfer Pressure 2 Pump4 100 mTorr 100 mTorr 100 mTorr 2 Torr 100 mTorr 2 Torr 2 Torr 2 Torr atm atm atm atm 1 MS MIDSTAGE 2 CF CONTRA FLOW...

Page 66: ...p Touch the Bargraph Display toggle box to switch the bar graph display between LOG BARGRAPH DISPLAY mode and LINEAR BARGRAPH DISPLAY mode LOG BARGRAPH DISPLAY In the LOG BARGRAPH DISPLAY mode the 50 segment bar graph display represents the entire leak rate range of the leak detector spanning from 10 11 atm cc sec to 100 atm cc sec The numerical display located to the upper right of the bar graph ...

Page 67: ...Model 979 Series Helium Mass Spectrometer Leak Detector D R A F T 9 1 5 0 3 2 25 Figure 2 14 Leak Detector Logarithmic Output Voltage Figure 2 15 Leak Detector Linear Output Voltage ...

Page 68: ...ions The 979 has pre programmed upper transfer pressure limits that are slightly greater than the default settings These limits prevent the operator from inadvertently setting the 979 to trans fer into test at too high a pressure resulting in excessive spectrometer tube contamination or ion source filament failure Touch DONE to return to the previous menu If you make changes to the settings touch ...

Page 69: ...igurations only CONTRA FLOWLEAK XFER The CONTRA FLOW LEAK XFER set point determines the test pressure cross over point at which the 979 transfers into the CONTRA FLOW LEAK test mode from Roughing mode or Gross Leak Test mode In the CONTRA FLOW LEAK test mode the gas sample is pumped through the leak detector and swept across the high vacuum pump foreline The CONTRA FLOW LEAK test mode allows for r...

Page 70: ... display the Units Set Up screen Figure 2 18 Figure 2 18 Units Set Up Screen 2 7 1 1 Leak Rate and Test Port Pressure Units Selection Select the leak rate and test port pressure units to be displayed on the leak rate bar graph and the digital touch screen display LEAK RATE UNITS Touch the LEAK RATE units toggle box to switch the leak rate units between atm cc sec mbar l sec Torr l sec and Pa m3 se...

Page 71: ...these functions should be performed by trained service personnel as they significantly affect the performance of the Model 979 Touch the BACK box from this screen to display the First Menu screen Touch the NEXT box to display the Home screen Figure 3 1 Second Menu Screen 3 1 Version The VERSION screen Figure 3 2 provides system software revision information Figure 3 2 Version Screen BACK UNITS SET...

Page 72: ...rvice Menus are calculated when the 979 performs functions such as CALIBRATE and ZERO Changing these values can cause unreliable test results Touch the SERVICE MENUS box to display the Service Menu screen Figure 3 3 This screen shows the functions that may be performed as part of a troubleshooting or maintenance routine To return to the Second Menu screen touch the BACK box from the Service Menu s...

Page 73: ...ured helium leak rate is currently less than the minimum displayable value The light may flash briefly as the system recovers from a leak indication and the dis playable leak rate approaches zero If the AUTO ZERO 0 is turned on the UNDER light may also flash briefly as the system resets the zero point to a lower value The 979 does not display a leak rate while the UNDER light is on If this light s...

Page 74: ...mplifier offset This value is used by the service technician to evaluate the condition of the preampli fier The normal operating range is between 35 and 80 If this value is outside of the range contact your local Vacuum Technologies service representative 3 1 2 Manual Spectube Tuning Touch the MANUAL SPECTUBE TUNING box to display the Manual Spectube Tuning screen Figure 3 5 This screen is used to...

Page 75: ...nual adjustment of this parameter The repeller volt age parameter is used to tune the leak detector maximizing the leak detector output for a peak helium signal The repeller voltage parameter is adjusted before the leak detector is calibrated to helium This parameter is not adjusted automatically during the Calibration routine Typical Repeller Voltage values range from 320 VDC to 360 VDC 3 1 2 3 E...

Page 76: ...C to 200 VDC 3 1 2 6 Suppressor Voltage The SUPPRESSOR indicator displays the current Suppressor Voltage value in the preamplifier in the spectrometer tube The suppressor voltage parameter is not variable This parameter cannot be changed by the operator 3 1 2 7 Fixed Focus Voltage The FIXED FOCUS Voltage indicator displays the current Fixed Focus Voltage value of the ion source in the spectrometer...

Page 77: ...o that valve The valve changes state and the box changes from OPEN to CLOSE Touch DONE to return to the maintenance menu screen The valve state displayed to the right of each valve control box represents the current state of the corresponding valve The normal operating states of valves for single mechanical and dual pump systems are provided in Table 3 1 and Table 3 2 on page 3 8 respectively Tabl...

Page 78: ...V1 V2 V4 V5 V6 V7 V8 VENT O C C O C C C ROUGH C O C C C C C GROSS TEST C O C O C C O CONTRA FLOW C O C O O C C MIDSTAGE C C O O O C C SNIFF MODE C O C O O C C O Open C Closed TEST PORT ROUGH VALVE ROUGH PUMP P P V1 VENT TEST PORT TC SYSTEM TC SPEC TUBE V4 MIDSTAGE TURBO PUMP V5 FORELINE FORE PUMP CAL LEAK V7 3 WAY V2 V6 TESTPORT V8 GROSS GROSS LEAK OPTION GROSS LEAK OPTION NEEDLE VALVE LEAK VALVE ...

Page 79: ...en and return to the previous menu 3 1 5 Gauge Calibration Procedures Touch the GAUGE CAL box to display the Gauge Calibration screen Figure 3 9 which provides the ability to perform a calibration on either the system pressure thermocouple button TC or the test port thermocouple gauge NOTE The calibration of the test port thermocouple TC gauge is factory set and requires the use of a reference TC ...

Page 80: ...e system is not already in VENT mode press the VENT button 4 Press the TEST button and verify that the leak detector transfers to FINE TEST mode displaying 10 9 atm cc sec or lower 5 Wait approximately five minutes for the vacuum system pressure to stabilize 6 Move to the GAUGE CALIBRATION screen Figure 3 9 on page 3 9 if you are not already there 7 Touch the SYSTEM TC ZERO box A CAL OK indication...

Page 81: ... the SYSTEM TC ATM box confirms that the calibration was successful A FAILED message indicates that the calibration was not successful This could be the result of a defective or contaminated thermocouple gauge or that the actual pressure was not at or near atmosphere 5 Power down the leak detector 6 Plug the mechanical pumps into the appropriate receptacles and turn the power back on 3 1 5 2 Test ...

Page 82: ...the calibration was not successful A FAILED message can result from a defective or contaminated thermocouple gauge or the fact that the actual pressure was not at or near zero 7 Touch the DONE button to leave the screen and return to the previous menu 3 1 5 2 2 Atmospheric Calibration 1 Place the service key T009 into the key switch and set the key switch to the SERVICE position 2 If the system is...

Page 83: ...r as required basis or if the item has not required maintenance on an annual preventive basis If your 979 leak detector requires service that is not covered in this section contact Vacuum Technologies Customer Service at 1 800 8VARIAN Important Reminders In addition to the safety notes at the beginning of this manual heed the following notes cautions and warnings when performing maintenance WARNIN...

Page 84: ... reduces their ability to hold a vacuum NOTE If applicable apply a small amount of Apiezon L grease and wipe the O rings shiny dry NOTE Due to the effective cleaning nature of VacuSolv solvent and its residue free properties Vacuum Technologies Component and Spectrometer Tube Cleaning Kit Part Number 670029096 used in accordance with the kit instructions is recommended for cleaning the spectromete...

Page 85: ...ction 4 3 Spectrometer Tube Overhaul on page 4 4 Table 4 2 As Required Maintenance Function Most Common Symptom Refer to Spectrometer tube cleaning Loss of sensitivity increase in background high ion voltage 300 VDC required to tune the leak detector Section 4 3 Spectrometer Tube Overhaul on page 4 4 Ion source replacement Filament failure as soon as convenient after second filament is in use Sect...

Page 86: ... Recalibrate the Internal Calibrated Leak Helium calibrated leaks typically degrade at 3 percent per year The calibrated leak sup plied with your 979 must be checked at least once a year to ensure it is at the value stated on its tag Failure to check the leak could result in unreliable testing You can arrange for testing and re calibration at a lab of your choice Vacuum Technologies provides NIST ...

Page 87: ...sphere Perform this procedure every twelve months or sooner if required Access to the spectrom eter tube is gained by removing the 2 Phillips screws from the front panel and dropping the top of the front panel down NOTE Rebuilt spectrometer tubes are available from Vacuum Technologies on an exchange basis Contact the Vacuum Technologies Service Center 1 800 8VARIAN for details Table 4 3 Tools and ...

Page 88: ...1 5 0 3 1 Remove the 2 Phillips screws from the Model 979 front panel Figure 4 1 Figure 4 1 Front Panel 2 Lean the top of the front panel forward to allow access to the spectrometer tube assembly Be careful not to place tension on the front panel display PCB harness 1 1 2 2 ...

Page 89: ... three connectors on the top of the unit indicated by in Figure 4 2 and the ground cable the spectrometer tube is attached by a KF 25 ISO NW 25 quick clamp and a wing nut located below the tube not shown in this view 4 Remove the three connectors from the top of the spectrometer tube Figure 4 3 The connector cables are labeled TC Ion Source and Preamplifier If the cables are not labeled label them...

Page 90: ...be magnet by removing the screw with a slotted screwdriver Figure 4 3 on page 4 7 6 Remove the wing nut located underneath the shelf below the spectrometer tube Figure 4 4 Figure 4 4 Wing Nut 7 Remove the KF 25 ISO NW 25 quick clamp to disconnect the spectrometer tube from the 979 vacuum system Figure 4 5 Figure 4 5 KF 25 Quick Clamp ...

Page 91: ... clean non magnetic surface CAUTION If the spectrometer tube magnet comes in contact with a magnetic surface it may become de magnetized causing the spectrometer tube to lose sensitivity CAUTION Do not remove the 6 magnet body bracket screws shown in Figure 4 6 while performing maintenance on the spectrometer tube Figure 4 6 Magnet Body Bracket Screws ...

Page 92: ...ure 4 7 Figure 4 7 Magnet Assembly Slotted Screws 10 Carefully slide the magnet assembly off of the spectrometer tube body If the magnet assembly does not slide off easily it may be necessary to loosen the tuning magnets by backing out the set screws located on both sides of the assembly Figure 4 8 Do not remove the set screws and tuning magnets completely Figure 4 8 Tuning Magnet Set Screws ...

Page 93: ...ing the Button TC 1 Remove the 4 Phillips screws that hold the Button TC header Figure 4 9 Figure 4 9 Button TC Assembly 2 Remove the Button TC header Figure 4 10 by pressing down on the Button TC center post and lifting the header up and off of the Button TC Figure 4 10 Removing the Button TC ...

Page 94: ...e the header from the Button TC Be careful not to damage the sensing wire CAUTION The sensing wire on the bottom side of the Button TC is approximately 3 mils thick Care must be taken not to damage this wire 4 Remove the Button TC carefully and place it sensing wire side up as shown in Figure 4 11 contact pin side down on a clean surface Figure 4 11 Button TC Wires View with Header on 5 Carefully ...

Page 95: ...formance See Section 4 4 Ion Source Replacement Outside of Annual Maintenance on page 4 20 when replacing the ion source outside of annual maintenance 1 Remove the 4 Phillips screws that hold the ion source header piece repeating steps 1 2 and 3 Section 4 3 2 Removing the Button TC on page 4 11 to release the ion source 2 Remove the ion source from the spectrometer tube body Figure 4 12 Figure 4 1...

Page 96: ...Figure 4 13 and cavity Figure 4 14 for deposits and discoloration When examination is completed dispose of it properly or return it to Vacuum Technologies for exchange Figure 4 13 The Ion Source 4 Looking into the ion source cavity Figure 4 14 you will see the ground slit plate Figure 4 14 Ion Source Cavity ...

Page 97: ...ell for this procedure 4 3 4 Removing the Preamplifier CAUTION The preamplifier is a static sensitive device Wear a grounding device while the preamplifier is being handled 1 Remove the 4 Phillips screws that hold the preamplifier header piece repeating steps 1 2 and 3 to release the preamplifier Section 4 3 2 Removing the Button TC on page 4 11 to release the preamplifier 2 Carefully remove the p...

Page 98: ...ree the magnet pole piece Figure 4 17 Figure 4 17 Magnetic Pole Piece 2 Pick up the spectrometer tube body and tilt it over to remove the magnetic pole piece 3 Remove the O ring from the magnetic pole piece and place both the O ring and the magnetic pole piece on a clean surface Figure 4 18 Figure 4 18 Removing the O ring from Magnetic Pole Piece ...

Page 99: ...4 19 Removing the Second Magnetic Pole Piece 4 3 6 Examining and Cleaning the Spectrometer Parts 1 Using the Scotch Brite pad from the spectrometer tube cleaning kit polish away any discolored areas inside the spectrometer tube cavity 2 Using the Scotch Brite pad polish away any discolored areas of the ground slit plate Figure 4 20 Figure 4 20 Discolored Ground Slit Plate CAUTION The ground slit p...

Page 100: ...Cleaning Wipe CAUTION The sensing wire on the bottom side of the Button TC is approximately 3 mils thick Care must be taken not to damage this wire 5 Examine the Button TC taking care not to damage the wires If there is no damage it may be reused after it is properly cleaned NOTE If you were seeing false system pressure readings prior to overhaul it may be best to replace the Button TC whether or ...

Page 101: ...ly reassemble the spectrometer tube Figure 4 24 in the reverse order of these instructions NOTE The preamplifier assembly has a slot that must be aligned with the alignment pin in the preamplifier cavity of the spectrometer tube body The ground slit plate has a hole in it that must be aligned with the hole on the bottom of the spectrometer tube body ion source cavity CAUTION The ion source must be...

Page 102: ...h hands thoroughly after handling the Ion Source and especially before smoking or eating CAUTION Use powder free butyl or polycarbonate gloves to prevent skin oils from getting on vacuum surfaces Tools Phillips screwdriver Parts Ion Source 1 Turn off the main power switch located on the back of the 979 leak detector 2 Remove the 2 Phillips screws from the front panel of the leak detector and drop ...

Page 103: ...ube Overhaul on page 4 4 9 When examination is completed properly dispose of the ion source or return it to Vacuum Technologies for exchange 4 4 1 Reassembly 1 Replace the ion source see Figure 4 24 on page 4 19 NOTE The ground slit plate has a hole in it that must be aligned with the hole on the bottom of the spectrometer tube body ion source cavity Figure 4 24 CAUTION The ion source must be alig...

Page 104: ...ip Seal Replacement Refer to the TriScroll Tip Seal Replacement Manual provided with the tip seal set See Section 4 6 979 Spare Parts List for the appropriate tip seal set part number When per forming a tip seal replacement the exhaust filter should also be replaced See Section 4 6 979 Spare Parts List for the replacement exhaust filter part number 4 6 979 Spare Parts List Table 4 4 979 Spare Part...

Page 105: ...uch Screen Assembly Call Vacuum Technologies Front Housing Call Vacuum Technologies Rear Housing Call Vacuum Technologies V70D Turbo Pump Exchange Program Call Vacuum Technologies V70LP Turbo Pump Exchange Program Call Vacuum Technologies Tip Seal Set TriScroll 300 Series Primary Pump PTSS0300TS Maintenance Tool Kit TriScroll Primary Pump PTSS0600TK Tip Seal Set TriScroll 600 Series Primary Pump P...

Page 106: ...Length NW25 Flange K9565306 Power Probe 25 Length NW25 Flange K9565307 Spare Tip Filters for Power Probe Qty 10 K9565303 Throttle Valve NW25 Flange R1947301 Elite Z Mechanical Pump Fluid 695409005 Calibrated Leak 10 5 10 6 NW25 Flange F8473320 Calibrated Leak 10 7 NW25 Flange F8473321 Calibrated Leak 10 8 NW25 Flange F8473322 Calibrated Leak 10 9 NW25 Flange F8473323 Calibrated Leak 10 10 NW25 Fla...

Page 107: ...ptically isolated 5 VDC to 24 VDC discrete I O interface Non isolated Serial RS 232 interface Non isolated analog 0 V to 10 V output for the 979 Series Leak Detectors The Remote Control connector provides Non isolated serial interface and power connection for the Universal Remote A 1 Optically Isolated Outputs Table A 1 on page A 2 provides the output information for the I O discrete connections F...

Page 108: ...en Leak Rate is greater than set point 2 5 REJ 3 Level Active when Leak Rate greater than set point 3 6 REJ 4 Level Active when Leak Rate greater than set point 4 7 START OUT Level Active High when 979 in Rough Mode 8 VENT OUT Level Active High when 979 in Vent Mode 9 TEST OUT Level Active High when 979 in Test Mode 10 BUSY OUT Level Active High when 979 in Busy Mode 11 WAKE UP OUT Level Active Hi...

Page 109: ...ary Table of Optically Isolated Inputs Pin Input Name Momentary or Level Description 1 Input Common N A Customer supplied GND for all P101 inputs 21 START IN Momentary 200 ms High Pulse to initiate 979 Roughing Mode 22 VENT IN Momentary 200 ms High Pulse to initiate 979 Vent Mode 23 HOLD IN Momentary 200 ms High Pulse to initiate 979 Hold Mode 20 SPARE_IN_5 Spare input 5 24 AUTOCAL Momentary 200 m...

Page 110: ...ground and are not isolated Electrical characteristics comply with EIA TIA Standard EIA TIA 232 E Figure A 4 979 COM Cable Wiring Diagram Table A 3 Summary Table of Non Isolated I O Pin Input Name Signal Spec Description 15 RxD RS 232 Spec Receiving Data to the 979 16 RTS RS 232 Spec Request to Send from the 979 17 TxD RS 232 Spec Transmitted Data from the 979 18 CTS RS 232 Spec Clear to Send to t...

Page 111: ...r the Universal Remote unit Table A 4 provides non isolated serial and power information Table A 4 Summary Table of Non Isolated Serial and Power Pin Input Name Signal Spec Description 2 RxD2 RS 232 Spec Receiving Data from the Universal Remote 3 TxD2 RS 232 Spec Transmitted Data to the Universal Remote 5 24 RET PWR GND Common for power and signals 9 24 V PWR 24 VDC power for the Universal Remote ...

Page 112: ...Model 979 Series Helium Mass Spectrometer Leak Detector This page intentionally left blank D R A F T 9 1 5 0 3 ...

Page 113: ...the current state or value of a volatile leak detector parameter Words that begin with INIT are commands for the controlling device to set non volatile leak detector parameters Other commands do not require a parameter and do not begin with any special character s Successful inquiries respond with data followed by a space then ok CR LF as speci fied in the tables of this appendix Unsuccessful inqu...

Page 114: ...liseconds between each character and terminating the command with a carriage return CR The intended command must be transmitted one character at a time then wait for the echoed response from the 979 before transmitting the next character and then terminating the command with a carriage return CR Windows 95 and later versions contain a serial communications program called HyperTerminal a useful too...

Page 115: ...nfigure and verify the port settings are correct 11 Ensure that the Settings tab is configured as follows Terminal keys radio button selected Ctrl H radio button selected Auto detect selected from the Emulation pull down list ANSI entered in the Telnet terminal ID 500 set in the Background buffer lines field 12 Click ASCII Set Up The ASCII Set Up dialog box appears 13 Ensure that the settings are ...

Page 116: ... box appears 3 Navigate to a location enter a file name and select a file type txt text file Notepad doc Word xls Excel 4 Click Save The Capture Text dialog box reappears 5 Click Start to log data 6 Select Transfer Capture Text Stop to end text capture 7 Open the file where the data was stored and select File Print Example You can use the above procedures to poll the 979 leak rate using HyperTermi...

Page 117: ...ure EMISSIONCURRENT Reports the emission current EXPONENT A two character minus followed by one digit number indicating the current manual mode exponent The exponent is within the least sensitive range as reported by RANGE and the three lower more negative exponent ranges See also INIT EXPONENT EXTLEAK Reports the currently stored value of the external standard leak FILAMENTBIAS Reports the filame...

Page 118: ...ng the reject leak rate most recently input using INIT xREJECT NOTE REJECT and 1REJECT refer to the same variable REPELLER Reports the repeller voltage ROUGH Reports the currently stored Test Sequencer rough time RSONOFF Reports the status of the Rangestop function Enabled or Disabled SEQONOFF Reports the status of the Auto Sequencer Enabled or Disabled SETUP Seven lines Each begins with a cr lf T...

Page 119: ...ro 0 0 off 1 on INIT CL XFER Preceded by X XE XX sets the value of the contra flow mode crossover pressure in Torr INIT DAC Preceded by a number 0 to 255 sets the offset of the leak rate output voltage DAC INIT DISPLAY Preceded by LOG or LINEAR sets the large bar graph to a log or linear display INIT EMISSION A four digit number of microamps in the range 0300 to 2000 which sets the emission curren...

Page 120: ...wo digit exponent the helium leak rate number in atm cc sec Values outside the working range of the leak detector are not stored INIT 1REJECT Same as INIT REJECT INIT 2REJECT Same as INIT 1REJECT but for Reject Set Point 2 INIT 3REJECT Same as INIT 1REJECT but for Reject Set Point 3 INIT 4REJECT Same as INIT 1REJECT but for Reject Set Point 4 INIT AREJECT Same as INIT 1REJECT but for the Audio Rej...

Page 121: ...l to match a calibration standard leak PUT ION A three digit number of volts in the range 200 to 350 which sets the ion voltage of the ion source PUT OFFSET A two digit number in the range 00 to 99 which sets the percentage of an offset variable PUT RANGE A two character number indicating the exponent of the least sensitive range of detectable leak Acceptable values are 0 through 6 Unacceptable va...

Page 122: ...egin a roughing and testing sequence RUN Starts the turbo and spectube after IDLE command SNIFF Enables the internal sniffer mode SYTCATM Sets the current system thermocouple reading to represent atmospheric pressure Success is indicated by the normal ok response SYTCZERO Sets the current system thermocouple reading to represent a pressure that is too low for a thermocouple to read Success is indi...

Page 123: ...ak detection C 2 Classes of Leak Detection There are four general classes of leak detection Hermetic Enclosures or parts thereof These are tested to prevent entrance of contaminants or loss of fluid that would affect performance of the enclosed unit Exam ples electronic devices integrated circuits sealed relays motors ring pull tab can ends and multipin feedthroughs Hermetic Systems These are test...

Page 124: ...usually expressed in torr or microns millitorr per hour The flow rate should be expressed in torr liters second Conversions 1 std cc sec 0 76 torr liter sec 1 torr liter sec 1 3 std cc sec 1 atm cc sec9 7 x 104 micron cubic feet per hour or practically 105 micron CFH µCFH 1 µCFH or practically 10 5 std cc sec for practical purposes equal Numerical Notation Exponential System Most leak rates of com...

Page 125: ...tely 10 3 std cc sec This method tests for ultrasonic sounds coming from a gas leak and is used for testing of high pressure lines Halogen sensitive to halogen elements or compounds especially refrigerant gases This method is good to approximately 10 5 std cc sec in most cur rent applications but extendable to 10 9 std cc sec under some limited situations It is critically dependent on operator jud...

Page 126: ...ted The resulting current is amplified and a leak rate bar graph indicates the presence and amount of helium C 5 2 Application as a Leak Detector A mass spectrometer leak detector consists of a spectrometer tube the electronics to operate and interpret it and a high vacuum system to maintain proper vacuum In addition means are provided for connecting a test object a rough vacuum pump and a system ...

Page 127: ...c sec per square centimeter of surface area Variation in Leak Sizes Leaks unintentionally built in at joints during manufacture may vary from hour to hour and day to day Breathing on a 10 6 std cc sec leak provides enough moisture to close it tempo rarily perhaps for several days Atmospheric particles can close a leak of this size Never depend on an accidentally made leak to remain constant Manufa...

Page 128: ... small jet of helium to locate individual leaks or surrounded by helium hooded for an overall leak check Figure C 1a Test Piece Evacuated Tracer Probe Used to Locate Leak Figure C 1b Test Piece Evacuated and Hooded with Helium Atmosphere to Determine Overall Leak Rate C 6 2 Test Piece Pressurized Figure C 2 Figure C 2 Test Piece Pressurized Detector Probe Used to Locate Leak Leak Detector Test Pie...

Page 129: ...ar Used to Determine Overall Leak Rate Sometimes it is necessary to leak check a completely sealed object This may be done by placing helium inside the object before sealing either 100 or mixed with other gas used for backfilling The object is then placed in a vacuum chamber connected to the leak detector Helium escaping from the object into the vacuum chamber is detected by the spectrometer tube ...

Page 130: ...nto a magnetic field where the mass 4 helium ions are deflected 90 degrees see Figure C 5 Only helium ions reach the collector An extremely stable electrometer provides an electron current to the collector which neu tralizes the current produced by the collection of helium ions The feedback current is pre sented on the leak rate bar graph Since this current is directly proportional to the number o...

Page 131: ...o be tested is rough pumped by a mechanical vacuum pump before they are connected to the spectrometer tube This prevents overloading the vacuum pumping system Figure C 5 Magnetic Separation Principle To Preamplifier Collector Helium Ions pass through slit and are collected Heavier Ions Lighter Ions Magnetic Field deflects Helium Ions 90 other ions more or less than 90 ...

Page 132: ...Model 979 Series Helium Mass Spectrometer Leak Detector This page intentionally left blank D R A F T 9 1 5 0 3 ...

Page 133: ...16 Forepump 1 16 Rough pump 1 16 Rough valve 1 16 Turbo pump 1 16 Circuit Sketch Discrete I O input A 3 Discrete I O output A 2 Cleaning Button TC 4 18 Ground slit plate 4 17 Magnetic Pole Pieces 4 18 O rings 4 19 Spectrometer tube 4 17 Communication panel 1 14 Communications protocol 2 26 B 1 Condition indication 2 8 Condition states table 2 10 Contra Flow leak xfer 2 27 Conversion chart Linear o...

Page 134: ...on 3 9 Atmospheric 3 11 System pressure 3 11 Test port pressure 3 11 Vacuum low pressure 3 10 Gauge calibration screen 3 9 Gross leak xfer 2 27 Gross test only mode 2 22 H Halogen C 3 Helium C 3 Helium for sealing C 7 Helium mass spectrometer leak detection C 4 Hermetic Enclosures C 1 Systems C 1 High sensitivity 2 23 Home screen 2 6 2 8 Condition indication display 2 8 Digital leak rate display 2...

Page 135: ...onfiguration 2 21 Manual spectube tuning screen 3 4 Manual valve ctrl screen 3 7 Manual zeroing 3 3 Manual zeroing and calibrate Cal screen 3 3 Mass spectrometer leak detector C 8 Mass spectrometry principles C 4 Mechanical pump maintenance 4 22 Oil sealed pump 4 22 TriScroll pump 4 22 Menus Touch panel 2 6 Touch screen boxes 2 9 MENUS box 2 8 Model 979 series configurations 1 1 Dual dry mechanica...

Page 136: ... 20 Rough only mode selection 2 19 Rough pump Circuit breaker 1 16 Power 1 16 Size selection 2 20 Rough pump set up 2 19 Rough pump set up screen 2 19 Rough time variable 2 18 Rough valve Circuit breaker 1 16 Roughing valve power 1 16 RS 232 Serial non isolated A 4 S Scheduled maintenance 4 3 Sealing with helium C 7 Second menu screen 2 28 3 1 Second menu selection screen 2 28 Service 3 2 Version ...

Page 137: ...acuated C 6 Pressurized C 6 Test port pressure 2 8 2 9 Units 2 28 Test port pressure gauge calibration 3 11 Atmospheric 3 12 Vacuum low pressure 3 12 Test time variable 2 18 Test Hold button 1 13 Testing for leaks C 1 Touch panel home screen 2 6 2 8 Touch panel screen Changing variables 2 6 Touch panel screen menus Selecting options 2 7 Tracer probe to locate leak C 6 Transfer point set up Contra ...

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