Varian 948, 947, 960 Operation And Service Manual

Models

947, 948 and 960

Leak Detectors

vacuum technologies

OPERATION AND
SERVICE MANUAL

Part No. 699909947
Revision H
March 2003

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Models 947, 948 and 960 Leak Detectors

Contra-Flow, MacroTorr, TriScroll and ConvecTorr are trademarks or registered trademarks of
Varian Vacuum Technologies.

Apiezon is a registered trademark of M&I Materials Ltd.
Alconox i s a registered trademark of Alconox, Inc.
Loctite and PST are registered trademarks of Loctite Corporation.
Scotch-Brite is a trademark of 3M.

Skid-Mate is a registered trademark of Hardigg.

Copyright 2003

Varian Vacuum Technologies

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Table of Contents

Declaration o f Co n fo rmity ........ .. ... ............... ................ ............................ ................ .................... xiii

Warranty ..........................................................................................................................................xiv

Warranty Replacement and Adjustment ....................................................................................xiv

Factory Calibration Data ...................................................................................................................xv

List of Options or Accessories Included with System .................................................................xv

Hazard and Safety Information .................................. ..................................... .................. .. ....... xvi

Solvents ...............................................................................................................................xvii

Equipment, General ............................................................................................................ xviii

Power and Stat ic........ .. ............... ............................. ............... ............................. ............... xviii

Vacuum Equipment and Cleanliness............. .. ........................................ .. ............................xx

O-ring Care .. ... ............... ............................. ............... ............................. ............... ................xx

Spectrometer Tube...............................................................................................................xxi

Pumps...................................................................................................................................xxi

Varian Servic e s ................. ............... ............................. ............... ............................. ................xxii

Contacting Varian Vacuum Technologies .................................................................................xxii

Section 1. Introduction to Models 947, 948 and 960 Leak Detectors .............................................1-1

1.1 Platform E le c tronics........... ................ ............... ............................. ................ ......................1-4

1.2 Unpacking the 947/948/960.......................................... ................................................... ....1-4

1.2.1 Unpacking Instructions................................................................................................1-4

1.2.2 Removing the 947/948/960 from the Skid...................................................... .............1-5

1.2.3 Removing Loose Packing from Interior of 947/948/960..............................................1-6

1.3 Front Pa n el Con trols and Indica to rs ......... ............... ............... ............................. ................1-6

1.4 Inner Door Instruction Label.................................................................................................1-8

1.5 Rear Panel Power Connection and Circuit Breakers...........................................................1-9

1.6 Service Pendant.................................................................................................................1-10

1.7 Installation Preparation......................................................................................................1-11

1.7.1 Power......... .. ............................. ............................. ............................ .......................1-11

1.7.2 Liquid Nitrogen (Models 948/960 only).................................................... .................1-12

1.7.3 Oil-Sea l e d Va cuum Pumps......................... ............................ ............................. .....1-12

1.7.4 Specia l In s ta llation Require m e n t s................... .. ................ ............... .........................1-12

1.7.5 Instal la ti o n Se rv i ce s ........... ... ............................ ................ ............................ ............1-12

1.8 Storage .............................. ................ ............................. ............... ....................................1-13

1.9 Optional Rear Panel Interface Connections.......................................................................1-13

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Section 2. Leak Detector Integration ..............................................................................................2-1

2.1 Physica l C o n s id e ra tions ........................ ............... ............................. ............... ...................2-1

2.2 Common Co n f ig u ra tion............... ............... ............................. ............... ..............................2-1

2.3 Electronic Considerations for the Optional Rear Panel Interface.........................................2-6

2.3.1 Discrete I/O J120 Inputs .............................................................................................2-6

2.3.2 BCD J121 Outputs......................................................................................................2-7

2.3.3 Host Serial Port J123 Pinouts.................................................... .................... .............2-8

2.4 Optional Interface Connections............................................................................................2-9

2.4.1 Grounding and Isolation..............................................................................................2-9

2.4.2 Setup..... .. .. ............................. ................ ............................ ................ .......................2-10

2.4.3 Discret e I/O .. .. .. ............................. ............... ............................. ............... ................. 2-10

2.5 Operation using the Optional Rear Panel Interface................................ .................... .......2-12

2.5.1 Paralle l E n ab le..... ... ............................ ............................. ......................................... 2-12

Section 3. O p eration .............. ............................. ............................. ...............................................3-1

3.1 Front Panel LED Indicators and Controls ...........................................................................3-1

3.2 Initial Sys t e m Pa r a m e te r Setup ......................................... ................ ............... ................ ...3-3

3.2.1 Parameters and Operating Modes..............................................................................3-3

3.3 Start-Up .............. ................ ............................. ............... ............................. ......................... 3-8

3.3.1 Startup P ro c e d ur e.......................................... ................ ............................. .............. 3-10

3.4 Calibration and Sensitivity Checks.....................................................................................3-11

3.4.1 Calibration and Sensitivity Checks............................................................................3-12

3.5 Operating Procedures........................................................................................................3-13

3.5.1 Auto Ran gi n g ..... ............................. ............... ............................. ................ .............. 3 -14

3.5.2 Manual Ranging........................................................................................................3-15

3.6 Standby..............................................................................................................................3-16

3.7 Shutdo w n........................... ............................. ............... ............................. .......................3-16

3.8 Using the Pendant for Parameter Setup............................................................................3-17

3.9 Optional Discrete I/O..........................................................................................................3-18

Section 4. Maintenance ..................................................................................................................4-1

4.1 Daily Maintenance ..............................................................................................................4-5

4.1.1 Calibra tion Check.......... ............................. ............... ............................. ................ .....4-5

4.1.1.1 Leak Checking ................................. .. .................. .. .................. .. .................. ..4-5

4.1.1.2 General Suggestions for Leak Checking ........................................................4-6

4.2 Yearly Maintenance.............................................................................................................4-7

4.2.1 Replacing the Calibrated Leak.................................................................................... 4-7

4.2.2 Re-calibrate the Internal Calibrated Leak...................................................................4-7

4.2.2.1 Removing the Internal Calibrated Leak ......................... .................................4-7

4.2.2.2 Replacing the Internal Calibr ated Leak ..........................................................4-9

4.2.3 Liquid Nitrogen Cold Trap (Models 948/960 only) ....................................................4-10

4.2.4 Spectrometer Tube Overhaul....................................................................................4-11

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.4.1 Removal of the Spectrometer Tube and Preamplifier .......................... ........4-12

4.2.4.2 Disassembly of the Spectrometer Tube and Preamplifier ............................4-14

4.2.4.3 Spectrometer Tube Cleaning ............................................... ........................4-16

4.2.4.4 Reassembly of the Spectrometer Tube and Preamplifier ......................... ....4-16

4.2.4.5 Reinstallation of the Spectrometer Tube ......................................................4-19

4.2.5 Air Filte r................... .. ............................. ............................. ............................. .........4-20

4.2.6 Spectrometer Tube Exchange ..................................................................................4-21

4.2.6.1 Removing and Replacing both the Spectrometer Tube Assembly

and Preamplifier ....................................................................................................... 4-21

4.2.6.2 Reinstalling the Spectrometer Tube .............................................................4-21

4.2.7 TC1 and TC2 Gauge Replacement and Calibration .................................................4-23

4.2.7.1 Replacement of the TC1 Gauge in the Main Valve Block Assembly ............4-23

4.2.7.2 Replacement of the TC2 Gauge in the Service Block Assembly .................4-25

4.2.7.3 Thermocouple Gauge Calibration Procedures ..................... .. ......................4-27

4.2.7.4 System Pressure Gauge (TC2) Calibrati on ................. .................................4-27

4.2.7.4.1 Va c u u m (L o w P re s s ur e ) C a lib r a tion ... ............................. ..............4-27

4.2.7.4.2 Atmospheric Calibration ................................................................4-28

4.2.7.5 Test Port Pressure Gauge (TC1) Calibration ...............................................4-29

4.2.7.6 Vacuum (Low Pressure) Calibration .............................................................4-29

4.2.7.7 Atmospheric Calibration ...............................................................................4-30

4.2.8 Rough Pump and Forepump Oil Level Check (Oil-sealed Mechanical Pumps)........4-31

4.2.8.1 Condition of Oil (Oil-seal ed Mechanical Pumps) .................................. ........4-32

4.2.9 Cleaning the Test Port ..............................................................................................4-32

4.2.9.1 Removing the Test Port ................................................................................4-32

4.2.9.2 Examining and Cleaning the Test Port ................................... .................. ....4-33

4.2.9.3 Replacing the Test Port ................................................................................4-34

4.3 Spare Parts................ .. ............... ................ ............................ ................ ...........................4-34

4.3.9.4 Exchange Assemblies ........................... ...................... .................................4-34

4.3.9.5 Replacement Parts .......................................................................................4-35

Section 5. Troubleshooting .............................................................................................................5-1

5.1 Error Condition Codes ........................................................................................................5-2

5.2 Troubleshooting Symptoms and Solutions .............................................. ............................5-3

Appendix A. Service Pendant Keypad Functions ...........................................................................A-1

A.1 Keypad Functions................................................................................................................A-1

A.1.1 Using the Service Pendant ........................................................................... .............A-2

A.2 Glossary of Function Keys................................................... .. ..............................................A-3

A.3 Glossary of Input and Data Keys..................... ...................... ...................... ...................... ..A-4

Appendix B. Parts Replacement .....................................................................................................B-1

B.1 Removing th e C o v ers............. .. .. ............................. ............................. ...............................B-1

B.1.1 Opening the Turret .............. .. .................... .. ........................................ .. .....................B-2

B.1.1.1 Removing the Service Pendant Shelf.............................................................B-2

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

B.1.2 Removing the Top Panel .......... .. .................................................................... ...........B-3

B.1.3 Replacing all Panels and Covers ...............................................................................B-4

B.1.3.1 Replacing the Service Pendant Shelf.............................................................B-4

B.1.3.2 Replacing the Top Panel................................................................................B-5

B.2 Replacin g th e Io n S o ur c e ............. ............................. ............................ ..............................B-6

B.3 Replacin g th e T u rb o P um p.................... ............... ............................. ............................. .....B-9

B.3.1 Turbo Pump ...............................................................................................................B-9

B.3.1.1 Removing the Turb o Pu m p............................................. ............................. .B -1 0

B.3.1.2 Rep l a cing the Turbo Pum p..... ... ............... .......................................... ..........B-12

B.3.1.2.1 Examining and Cleaning Centering Rings, O-rings and Manifold.B-12

B.3.1.2.2 Connecting the Turbo Pump to the SVBA ....................................B-13

B.4 Replacing the Rough Pump...............................................................................................B-15

B.4.1 Wet Systems ...........................................................................................................B-15

B.4.1.1 Removing the Wet Sy s te m R o u gh P u m p ......................... ............................B-1 6

B.4.1.1.1 Replacing the Wet System Rough Pump....................................... B-17

B.4.1.1.2 Examining and Cleaning Centering Rings, O-rings and Manifold .B-17

B.4.1.1.3 Re-installing the Wet System Rough Pump ..................................B-18

B.4.2 Dry Systems ............................................................................................................B-20

B.4.2.1 Removing the Dry System Rough Pump......................................................B-20

B.4.2.2 Replacing the Dry System Rough Pump......................................................B-21

B.4.2.2.1 Examining and Cleaning Centering Rings, O-rings and Manifold ..B-21

B.4.2.2.2 Re-installing the Dry System Rough Pump ...................................B-21

B.5 Replacing the Forepump...................................................................................................B-22

B.5.1 Wet ..........................................................................................................................B-22

B.5.1.1 Removing the Wet System Forepump..........................................................B-23

B.5.1.2 Replacing the Wet System Forepump..........................................................B-24

B.5.1.2.1 Examining and Cleaning Centering Rings, O-rings and Manifold..B-24

B.5.1.2.2 Re -in s t al lin g th e W e t S ystem Forepump ................. ............... ......B - 2 4

B.5.2 Dry System ..............................................................................................................B-26

B.5.2.1 Removing the Dry S ystem Forepump....... .. .......................................... ........B-26

B.5.2.1.1 Removing the Isolation Valve from the Forepump.........................B-26

B.5.2.1.2 Removing the Nitrogen Purge Connection from Pump .................B-27

B.5.2.1.3 Re mo ving the Exhaust Fitting .............. ................ .........................B-27

B.5.2.1.4 Removing the Pump from the Cabinet ..........................................B-27

B.5.2.2 Replacing the Dry System Forepump ...........................................................B-27

B.5.2.2.1 Examining and Cleaning Centering Rings, O-rings and Manifold..B-27

B.5.2.2.2 Re-installing the Dry System Forepump .......................................B-28

B.5.2.2.3 Connecting the Nitrogen Purge Pump ..........................................B-28

B.5.2.2.4 Re pl a cing the Isolatio n Va lv e ............................ ............................B-28

B.5.2.2.5 Re pl a cing the Exhaust Fitting ................ ............................. ..........B-29

B.5.2.2.6 Completing Mounting the Pump to the Cabinet Floor ...................B-29

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Appendix C. Communications Protocol .........................................................................................C-1

C.1 Protocol (RS-232)...............................................................................................................C-1

Appendix D. Inputs and Outputs .................................................................................................... D-1

D.1 Service Ser i a l In t e rface (J1)..... .. ................ ............................ ................ ............................D-1

D.2 Optional Rear Panel Interface............................ ................................................................ D-1

D.2.1 Discrete I/O Parallel Interface (J120) ....................................................................... D-1

D.2.2 BCD Discrete Output Parallel Interfac e (J121) ....................... .................... .............. D-3

D.2.3 Interface (J122) for Optional Universal Remote Control ........................................... D-4

D.2.4 Host Serial Port (J123) ............................ ................................................... ..............D-4

Appendix E. 947/948 Specifications ...............................................................................................E-1

Appendix F. Accessories ................................................................................................................F-1

Appendix G. Leak Detection Theory ............................. ...................... ...........................................G-1

G.1 Leak Testing—Why is it Needed?......................................................................................G-1

G.2 Classes o f L eak D e te c tion ..... .. ................ ............... ............................. ............... ............... G-1

G.3 Termino lo g y ............................. ................ ............................ ................ ..............................G-2

G.4 Various Methods of Testing for Leaks................................................................................G-3

G.5 Helium Mass Spectrometer Leak Detection (MSLD) ........................ .. .. .......................... .. .G-4

G.5.1 Principles of Mass Spectrometry ..............................................................................G-4

G.5.2 Application as a Leak Detector .................................................................................G-4

G.5.3 The Nature of Flow in a Vacuum .................. .. .......................................... ................G-4

G.5.4 Facts About Leak Rates .......................... .................. .................. .................. ...........G-5

G.6 Leak Detection Methods....................................................................................................G-5

G.6.1 Test Piece Evacuated ..............................................................................................G-6

G.6.2 Test Piece Pressurized ............................................................................................ G-6

G.6.3 Test Piece Already Sealed .................................. .. ........................ .. ........................ .G-7

G.7 Mass Spectrometer Leak Detector—Simplified Description ..............................................G-8

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

List of Figures

Figure Description Page

1-1 947 Leak Detector......................................... .......................................... ...................... .. ....1-2

1-2 948/960 Leak Detector........................................................ .. ........................................ .. ....1-3

1-3 Front Panel Controls and Indicators...................................................................................1-6

1-4 Turret Door Instruction Label............................. ................... ................ ..............................1-8

1-5 Rear Po we r P a ne l............................... ............................. ............................. ......................1-9

1-6 Service Pendant.............................................. .................................. ................................1-10

1-7 Rear Panel Interface Connectors......................................................................................1-13

2-1 947 Flow Diagram.............................................. .. .. .......................... ....................... ............2-2

2-2 948 Flow Diagram.............................................. .. .. .......................... ....................... ............2-4

2-3 960 Flow Diagram.............................................. .. .. .......................... ....................... ............2-5

2-4 Rear Pan el....... ............... ................ ............................ ................ ............................. ...........2-9

2-5 Discrete Inputs/Outputs Isolated........................................... .................... .................... ....2-10

3-1 Front Panel LED Indicators and Controls............................. .................... .. .................... ....3-1

3-2 Start-u p C o n trols................................... ................ ............................. ............... ..................3-8

3-3 Exponent Display with Condition Code Indicated........... .................... .................... ..........3-11

3-4 Location of AUTO/MAN MODE Switch.............................................................................3-14

3-5 Service Pendant Keypad ......................................................... .. ...................... .. ...............3-17

4-1 Location of the Calibrated Leak..........................................................................................4-7

4-2 947/948/960 Spectrometer Tube Removal........................... ........................................ .. ..4-13

4-3 Spectrometer Tube Disassembly......................................................................................4-15

4-4 Spectrometer Tube Reassembly ......................................................................................4-16

4-5 Spectrometer Tube Reassembly (Ground Slit Plate)........................................................4-17

4-6 Spectrometer Tube Reassembly (Magnet Assembly) ......................................................4-18

4-7 947/948/960 Spectrometer Tube Installation.......................... ...................................... ....4-19

4-8 Air Filter Replacement ......................................................................................................4-20

4-9 947/948/960 Spectrometer Tube Installation.......................... ...................................... ....4-22

4-10 TC1 Gauge in the MVBA ........................................................................ ..........................4-23

4-11 TC2 Gauge in the SBA ............... .................... .................... ...................................... ........4-25

4-12 Rough Pump and Forepump Oil Level Check ..................................................................4-31

4-13 The Test Port............... ............................... ................. ............................... ......................4-32

4-14 Remove the Test Port Compression Ring and O-ring .................................................... ..4-33

4-15 Placing the O-ring and Compression Ring onto the Test Port......................... .................4-34

A-1 Service Pendant Keypad ................................................................................... .................A-1

B-1 Removing the Service Pendant Shelf............... ..................................................................B-2

B-2 The Top Panel at the Rear of the Turret........................... .................. ................................B-3

B-3 The Test Port............... ............................... ................. ............................... ........................B-3

B-4 The Top Panel from the Front of the 947/948/960.......................................................... .. ..B-4

B-5 Ion Sourc e Re p la c e m e n t .................. .. .. ............................. ................ ............................ .....B -6

B-6 Location of the Turbo Pump................................................................................................B-9

B-7 Turbo Power and Foreline to Turbo Connections.............................................. ...............B-10

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

B-8 The Turbo Power Connection........................................................................................... B-11

B-9 Radiator Clamp holding Fan to Turbo................... ................................................... .........B-11

B-10 Location of Forepump and Rough Pump — Wet and Dry Configurations........................B-15

B-11 Rough Pump Manifold and Exhaust Connections..................................................... .. .....B-16

B-12 Rough Pump Manifold and Exhaust Connections..................................................... .. .....B-18

G-1 Test Piece Evacuated: Tracer Probe Used to Loc ate Leak...............................................G-6

G-2 Test Piece Evacuated and Hooded with Helium Atmosphere to

Determine Overall Leak Rate ............................................................................................G-6

G-3 Test Piece Pressurized: Detector Probe Used to Locate Leak................. .. ...................... .G-6

G-4 Test Piece Sealed with Helium and/or Other Gases –

Bell Jar Used to D et e rmIne Overall Le ak Ra te........... .. ............... ................ ............... ....... G-7

G-5 Magnetic Separation Principle...........................................................................................G-8

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

List of Tables

Table Description Page

2-1 Valve Operation ................................................................................................................. 2-3

2-2 J120 Input Connections..................................................................................................... 2-6

2-3 J121 Ou tp u t Su mmary............................. ............................ ............................. ................. 2-7

2-4 J123 Pinout Summary........................................................................................................ 2-8

3-1 NOT READY Condition Codes ........................................................................................ 3-11

4-1 Schedu l ed M a in tenance ................................ ............................. ............................. .......... 4-3

4-2 As-Required Maintenance.................................................................. ............................... 4-4

4-3 Tools and Parts Required for Spectrometer Tube Overhaul............................................ 4-11

4-4 Exchange Assembly Parts............................................................................................... 4-35

4-5 Replac e m e n t Pa rts ........... ................ ............... ............................. ................ ................... 4-35

5-1 Error Condition Codes....................................................................................................... 5-2

5-2 Troubleshooting................................................................................................................. 5-3

C-1 Internal Operating Pa r ameters .................. ............................ ................ ............................ C-2

C-2 Non-volatile Operating Parameters ......... ............... ............... ................ ............... ............. C-5

C-3 Spectrometer Ope ra t in g Pa r a m e te rs ................... .. ............... ............................. ............... C-6

C-4 Command Parameters for Leak Detection Actions ........................................................... C-7

D-1 Service Serial Interface (J1) .............................................................................................. D-1

D-2 Optional Discrete I/O Parallel Interface (J120) ................................................................. D-1

D-3 Optional BCD Discrete Output Parallel Interface (J121) .................. .................................D-3

D-4 Optional Interface (J122) for Optional Universal Remote Control ..................................... D-4

D-5 Optional Host Serial Port RS-232 Interface (J123) ........................................................... D -4

E-1 947/948/960 Specifications ........................ .................. ................... .................. .................E-1

E-2 947/948/960 Model Types and Part Numbers ....................... ..................... .......................E-3

F-1 947/948/960 Accessories ............................... .. ........................................ .. ........................F-1

G-1 Decimal N o ta tion ...... .. ............... ................ ............................ ................ ............................ G-2

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D

eclaration of Conform

ity

Declaration of Conformity
Konformitätserklärung
Déclaration de Conformité
Declaración de Conformidad
Verklaring de Overeenstemming
Dichiarazione di Conformità
We/Wir/Nous/Nosotros/Wij/Noi: Varian, Inc.

declare under our sole responsibility that the product,
erklären, in alleniniger Verantwortung, daß dieses Produkt,
déclarons sous notre seule responsabilité que le produit,
declaramos, bajo nuestra sola responsabilidad, que el producto,
verklaren onder onze verantwoordelijkheid, dat het product,
dichiariamo sotto nostra unica responsabilità, che il prodotto,

Models 947, 948 and 960 Leak Detectors Operations and Service Manual

Declaration of Conformity

Varian Vacuum Technologies
121 Hartwell Avenue
Lexington, MA, 02421-3133 USA

to which this declaration relates is in conformity with the following standard(s) or other normative documents.
auf das sich diese Erklärung bezieht, mit der/den flogenden Norm(en) oder Richtlinie(n) übereinstimmt.
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.

89/336/EEC. . . . . . . . . . . . . . . . . . . . . . Electromagnetic Compatibility Directive

EN55011:1991 Class B . . . . . . . . . . . . . EMC/Limits for Radiated Emissions

EN55022:1995 Class A. . . . . . . . . . . . . EMC/Limits for Conducted Emissions

IEC 1000-4-2/IEC 1000-4-3. . . . . . . . . . EMC/Limits for Electrostatic Emissions

IEC 1000-4-4/IEC 1000-4-6

IEC 801-2 Crit B . . . . . . . . . . . . . . . . . . EMC/Immunity to Electromagnetic Fields and Transient Bursts

IEC 801-3 Crit A
IEC 801-4 Crit B

Frederick C. Campbell
Operations Manager
Varian Vacuum Technologies
Lexington, Massachusetts, USA

March 2001

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

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 warranty
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 war­ranty, 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 adjust­ment, 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, notwith­standing 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.

3/1/00

xiv

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Factory Calibration Dat a

Model Number: Date:
Serial Number: Initials:

Your Varian 947/948/960 leak detector has been thoroughly tested prior to shipment. It is shipped
tuned to helium on Filament No. 1. Normally, once set, the tuning adjustments are left untouched
and calibration may be verified as required.

The data recorded below includes readings taken during the final test prior to shipment. They are
convenient for reference purposes if tuning adjustments are altered. Slight changes may occur when
using Filament No. 2 or after an ion source is replaced.

Ion Chamber Voltage: VDC

Emission Current: mA

Fixed Focus Voltage: VDC

Repeller Voltage: VDC

Filament Bias Voltage: VDC

Variable Focus Voltage: VDC

Suppressor Voltage: VDC

Offset Index:

Gain:

Mechanical Pump Model: cfm VAC Hz

List of Options or Accessories Included with System

xv

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Hazard and Safety Information

This manual uses the following standard safety protocols:

WARNING The warning messages are for attracting the attention of the

operator to a particular procedure or practice which, if not
followed correctly, could lead to serious injury.

CAUTION The caution messages are displayed before procedures, which

if not followed, could cause damage to t he equipment.

NOTE The notes contain important information.

Operators and service personnel must be aware of all hazards associated with this
equipment. They must know how to recognize hazardous and potentially hazardous
conditions, and know how to avoid them. The consequences of unskilled, improper, or
careless operation 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/maintenance manuals and any additional information
provided by Varian Vacuum Technologies. All warning and cautions should be read
carefully and strictly observed. Consult local, state, and national agencies regarding specific
requirements and regulations. Address any safety, operation, and/or maintenance questions
to your nearest Varian Vacuum Technologies office.

xvi

Solvents

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

CAUTION The mechanical components of leak detectors are typically

cleaned with alcohol, methanol, or other solvents. When
heated, sprayed, or exposed to high-temperat ure equipment,
these solvents become flammable and explosive, causing
serious injury or death. Do not use these solvents near a
high-temperature source. Ventilate the working area with a
blower and work in a large, well-ventilated room.

Alcohol, methanol, or other solvents are irritants, narcot ics,
depressants and/or carcinogens. Their inhalation and/or
ingestion may produce serious side effects. Prolonged or
continued contact with the skin results in absorption through
the skin and moderat e toxicity. Always ensure that cleaning
operations are carried out in large, well-ventilated rooms, and
wear eyeshields, gloves, and protective clothing.

CAUTION Do not clean any aluminum parts with Alconox

not compatible wi th alum inum and will cause damage.

NOTE During reassembly, always use Loctite

®

PST®

(te f lon -impr egnated pipe thr ead com pound) on pi pe threads .

®

. Alconox is

xvii

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Equipment, General

WARNING The leak detector is not designed for use with hazard ous gases.

WARNING Equipment tightness is guaranteed for normal operating

CAUTION The performance and op erat ing safety of t his equipment can b e

Verify that the system to be tested has been purged of all
hazardous gases p rior to using the leak detector.When testing a
system that contained hazardous gases, the exhaust of the leak
detector should be connected to a scrubbed or toxic
containment exhaust. Exposure to hazardous gas es could resu lt
in serious i njury or death.

conditions when the equipment leaves the factory. It is the
user’s responsibility to maintain the level of tightness
particularly when pumping dangerous products.

guaranteed only if it is operat ed acc ording to normal cond itions
of use.

Power and Static

CAUTION Always allow at least 4 inches of clearance adjacent to the

ventilation holes at the front, back, and b ottom of the
equipment enclosure.

WARNING Disconnect power from t he leak detect or befor e performing any

maintenance procedure that requires physically disconnecting
any part of the system.

CAUTION Many components of the leak detector are static-sensitive

devices. Varian Vacuum Technologies recommends that you
wear a grounding device when performing any maintenance on
the leak detect or and especially when performing maintenance
of static- sensitive parts.

xviii

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

WARNING

Electrical insulation must include the appropriate br anch circuit
(at least 20 A), with long time delay and a reliable earth ground.
Do not use an extension cord.

Use only the power cord that was provided with your leak
detector. The use of extension cords is not recommended and
could result in damage to the equipment and loss of warranty.

To avoid electric shock, connect the product power cord to a
grounded p ower recep tacle. A prot ective ground connection by
way of the grounding conduct or in the power cord is essential
for safe operation.

Before powering up the leak detector for the first time, verify
that the leak detector is configured to operate from the local
mains supply voltage.

Opening the enclosure may expose hazardous voltages. Always
disconnect the power cord and any interface cables before
opening the enclosure. Do not touch the power inlet’s contacts
for at least 10 seconds after disconnecting the powe r cord.

CAUTION This equipment generates, us es, and can rad iate RF ener gy, and

if not installed and used in accordance with the instructional
manual, may cause harmful interference to radio
communications.

When this equipment is operated in a commercial
environment, operation is subject to the following conditions:

❑ This equipment may not cause harmful interference, and
❑ This equipment must accept any interference received,

including interference (RF and ESD) that may cause
undesired operation.

This equipment may need to b e reset after RF and/or ESD events
by cycling the Power Switch/Circuit Breaker on the back pane l
of the leak detector.

Operation of this equipment in a residential area is likel y to
cause harmful radio communications interference, in which
case the user will be required to cor rect the interference at his
own expense.

xix

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

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 servicing than in general vacuum
work:

CAUTION Do not use silicone oi l or sil icone grease.

Use powder-free butyl or polycarbonate gloves to prevent skin
oils from getting on vacuum surfaces.

O-ring Care

When removing, checking, or replacing O-rings, keep in mind the following:

Do not clean any aluminum parts with Alconox

®

. Alconox is

not compatible wi th al um inum and will cause damage.

NOTE Normally, it is unnecessary to use vacuum greas e. However, if it

must be used , avoid silicone types, and use it sparingly.
Apiezon

®

L grease (Varian Vacuum Technologies Part No.

695400004) is recommended.

NOTE Varian Vacuum Technol ogies recommends replacing all

O-rings during routine maintenance or during any maintenance
procedure requiring that O-rings be removed.

CAUTION Remove O-rings carefully with your fingers. Do not use metal

tools for this task. Follow these guidelines to prevent scratching
of any sealing surfaces:

❑ Wipe all O-rings clean with a lint-free cloth before

install ation to ensure that no foreign matter is present to
impair the seal.

xx

❑ Do not use grease or use other substances on O-rings that

wil l come in contact with the spectrometer tube.

❑ Do not use alcohol, methanol, or other solvents on O-rings.

To do so causes deterioration and reduces t he O-ring’s
ability to hold a vacuum.

❑ In allowable situations, apply a small amount of Apiezon

L

grease and wipe the O-rings “shiny” d ry.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Spectrometer Tube

NOTE VacuSolv, included in the Component and Spect rometer Tube

Cleaning Kit (Part No. 670029096), is recommended for
cleaning the spectrometer tube components.

VacuSolv can also be used for fine cleaning of other part s in the
leak detector’s vacuum system, such as valves and fittings. No
rinsing steps or high-temperature drying is requir e d foll o w ing
cleaning with VacuSolv. Although appropriate precautions are
advised, VacuSolv is compatible with most materials and does
not contain toxic chemicals or CFCs ( chlorofluorocarbons).

CAUTION The spectrometer tube operates at a very high vacuum

produced by the high vacuum pump. Service of the
spectrometer tube requires that t his vacuum be vented to the
atmosphere.

CAUTION Do not use grease or other sub st ance on O-rings that will come

in contact with the spectrometer tube.

Pumps

CAUTION If the spectrometer tube magnet comes in contact with a

magnetic surface, the magnet may lose its field strength,
causing the spectrometer tube to lose sensitivity.

WARNING Store the ion source in a cool, dry area in a tightly sealed

container. Wash hands thor oughly after handling the ion
source, especially before smoking or eating.

WARNING To avoid injury, use prop er lifting techniques when moving

pumps. Your system may have pumps that require two people
to move them safely.

WARNING The vacuum pumps are also compressors; incorrect operation

may be dangerous. Study the “Installation and Operation
Manual” enclosed with your pump bef o re starting pumps.

xxi

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Varian Services

The following are just a few of the many services that Varian offers its customers. Please see
our catalog, or contact us to learn of the services that are available. Contact Varian Vacuum
Technologies Customer Service at 1-800-8VARIAN for details.

❑ Rebuilt spectrometer tubes are available on an exchange basis.
❑ NIST-traceable calibrated leak testing and verification services.

Contacting Varian Vacuum Technologies

In the United States, you can contact Varian Vacuum Technologies Customer Service at
1-800-8VARIAN.

Internet users:

❑ Send email to Customer Service & Technical Support at

[e-mail]

❑ Visit our web site at www.varianinc.com/vacuum
❑ Order on line at www.evarian.com

See the back cover of this manual for a listing of our sales and service offices.

xxii

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Section 1. Introduction to Models 947, 948 and

960 Leak Detectors

Varian Vacuum Technologies’ Model 947, Model 948 and Model 960 are Platform
Auto-Test
are referred to as Models 947/948/960.

This manual provides you with:

Conformity, Warranty and Safety information is listed at the start of this book. This
information should be read before operating the equipment.

®

Helium Mass Spectrometer Leak Detectors. In this manual, these leak detectors

❑ Equipment descriptions
❑ Complete operating instructions, including control and indicator descriptions,

maintenance, calibration, and interfacing procedures

❑ Troubleshooting information

The 947/948/960 has rugged metal enclosures that are mounted on casters for greater
mobility. A key is used to access the lockable turret that houses the service pendant.

The 947/948/960 has the following basic components:

❑ Mechanical backing pump
❑ Mechanical roughing pump
❑ Spectrometer tube
❑ Contra-Flow
❑ Platform electronics
❑ Front panel and indicators

The 947/948/960 can be configured with dry or wet pumps. The 948/960 have a nitrogen
cold trap.

The platform electronics, service pendant, and displays are located in the turret. Leak rate
and system status information is displayed on the front panel, and is also available through
the rear panel I/O.

™

Vacuum system (960 uses conventional flow)

1-1

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

The Model 947 is shown in Figure 1-1. Descriptions of the turret and operational buttons
identified in Figure 1-1 follow the figure. Models 948/960 are shown in Figure 1-2.

➃

➀

➂

➁

Figure 1-1 947 Leak Detector

➀ Turret Enclosure for Service Pendant and electronics
➁ Operational

buttons

Start and Vent buttons

➂ Test Port Attachment
➃ Standard Leak

Label

Label with internal standard leak value

1-2

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Models 948/960 are shown in Figure 1-2. The door on the working surface of the 948/960
provides access to the nitrogen cold trap. Descriptions of the turret, operational buttons,
and nitrogen trap identified in Figure 1-2 follow the figure.

➀

➂

➃

➁

Figure 1-2 948/960 Leak Detector

➀ Turret Enclosure for Service Pendant and electronics
➁ Operational

buttons

Start and Vent buttons

➂ Liquid Nitrogen

trap

Access to Liquid Nitrogen Trap

➃ Test Port Attachment

1-3

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

1.1 Platform Electronics

The 947/948/960 use Varian Vacuum Technologies’ Platform leak detector electronics
architecture to:

❑ Operate the spectrometer assembly
❑ Control the mechanical and high vacuum pumps
❑ Control the valves
❑ Provide leak rate and system status information to the operator interface and rear I/O

An advanced electronics platform provides complete diagnostic information and allows
adjustments without testpoints or potentiometers. The platform is a collection of printed
circuit boards that operate using the PC/104 Bus Structure to perform the various functions
of a helium mass spectrometer leak detector. The microprocessor also stores key tuning
parameters and retains them in EPROM. This provides for fast recovery after a momentary
loss of line voltage.

1.2 Unpacking the 947/948/960

When receiving the 947/948/960, the following pieces are included:

❑ Models 947/948/960 leak detector
❑ Service Pendant
❑ Power cable (115 VAC or 230 VAC)
❑ Pump manuals (for the purchased configuration)

Refer to the Unpacking Instructions located on the outside of the shipping container before

opening the container. The 947/948/960 are carefully packed onto a shock absorbing skid
and enclosed by a heavy cardboard container banded to the skid. The factory packing
provides maximum protection during shipment.

1.2.1 Unpacking Instructions

To unpack the 947/948/960 and remove it from the skid:

1. Inspect the container for evidence of damage in shipment.

a. Do not discard any evidence of rough handling.

b. Report any damage to the carrier and Varian Vacuum Technologies Customer

Service at 1-800-8VARIAN without delay.

1-4

2. Carefully remove the outer shipping container.

3. Inspect the leak detector and related items immediately for any indication of shipping
damage.

4. Carefully cut the strapping holding the leak detector on the skid.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

5. Remove any loose boxes or packages and put them aside. Keep the original packing for

re-use in the event that it is necessary to return the leak detector to Varian Vacuum
Technologies.

6. Carefully remove the front brace by removing the two lag bolts.

7. Carefully remove the plastic bag covering the leak detector.

The leak detector can now be removed from the skid.

1.2.2 Removing the 947/948/960 from the Skid

There are two methods for removing the 947/948/960 from the skid. Both methods
require two people. The second method involves removing the Skid-Mates from the
skid.

WARNING Handle the leak detect or carefully and proper ly in the following

steps. Per sonal injury or damage to the leak detector could
result from improper handling. The 947/948/9 60 is heavy and
can cause personal i njury if not handled carefully when
removing i t from the sk id.

Method 1

1. With the assistance of a helper, carefully roll the leak detector toward 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 “Unpacking Instructions” as a lever, carefully raise

the front edge of the skid between 1" and 2".

2. While a helper holds the leak detector against the back brace, unscrew and remove the

front two Skid-Mates (the blue donut-shaped mounts at the front of the skid) by turning

them in a counterclockwise direction.

3. Make sure the helper is still holding the leak detector against the back of the skid, then

gently lower the front of the skid to the floor.

4. Carefully and slowly roll the leak detector off the skid and onto the floor.

1-5

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

1.2.3 Removing Loose Packing from Interior of 947/948/960

Once the 947/948/960 is off the skid, the loose packing inside the enclosure must be
removed.

1. Open the front panel of the 947/948/960, which is the main access to service the pumps
and the spectrometer tube.

2. Take out and remove all loose packing from inside the leak detector.

1.3 Front Panel Controls and Indicators

The front panel controls and indicators are identified by number in Figure 1-3. Descriptions
of each numbered item follow Figure 1-3.

12

34567

8

10

12 13

11

9

14 15

Figure 1-3 Front Panel Controls and Indicators

1 Volume Control Controls the volume of the audible leak rate signal.

19

16 17 18

1-6

2 Display Button Displays the selected reject level of the leak detector using the

50-segment leak rate bar graph and the appropriate range exponent.

3 Rough Pump

Power Switch

4 Detector Power

Switch

Controls the power to the roughing pump.

Controls the power to the backing pump and high vacuum pump.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

5System Pressure

Bar Graph

6 Transfer to Fine

Test Switch

7 Display Set Point

Button

8Test Port

Pressure Bar
Graph

9 Leak Rate

Exponent Display

10 Leak Rate

Mantissa Bar
Graph

11 Leak Rate Over

Indicator

12 Auto/Man Mode

Switch

Displays system pressure monitored at the inlet of the spectrometer
tube on a 20-segment bar graph. The green portion of the graph
indicates normal operating vacuum level.

Holds the leak detector in gross leak mode in the NO position. In the
AUTO position, it transfers into fine test mode.

Displays the transfer-pressure set point on the Test Port Pressure bar
graph.

Displays the test port pressure as measured by a thermocouple
gauge mounted near the test port. Used as an indicator to help
prevent damage to the detector due to over-pressure situations.

Indicates the leak rate range exponent in a two-digit numeric display.

−

11

Capable of showing 10

range to 100 range in atm cc/sec. The

RANGE EXPONENT is also used to display the error condition code.
A 50-segment bar graph. The left most segment indicates 0.0 and is

on at all times.

Goes on when the upper limits of the Leak Rate scale have been
exceeded.

Selects automatic ranging or manual ranging. When in the AUTO
position, the display starts each test sequence in the least sensitive
range, and ranges down to the most sensitive range. When in the
MAN position, the operator selects a single range to display the range
manually.

13 Smaller/Larger

Exponent
Selection Buttons

When Manual Range changing is selected:

❑ SMALLER decreases the leak rate exponent.
❑ LARGER increases the leak rate exponent.

Holding the SMALLER

or LARGER button down for more than

3 seconds (wait for the exponent to begin flashing) stores the value of
the manual range exponent in EPROM. The range changes one
decade each time a button is pushed.

14 Start Button Press to initiate test mode.
15 Vent Button Press to initiate vent mode. This allows a test device to be connected

to the 947/948/960 for leak detection.

16 Zero Button Press to initiate auto-zero sequence. The leak detector automatically

zeroes a negative signal.

17 Std Leak Button Press to initiate Std leak check. Opens the standard leak test valve so

that the calibrated leak can be measured to check the leak detector.

1-7

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

18 Auto Cal Button Press to initiate automatic calibration check. The system must be in

TEST mode to initiate Auto Cal. During the check, all front panel
pushbuttons are disabled. The 947/948/960 transitions back to TEST
mode at the completion of the Auto Cal routine.

19 LED Display Area Refer to Section 3, “Operation” on page 3-1 for definitions of the

LEDs.

1.4 Inner Door Instruction Label

The label on the inside of the lockable turret door (Figure 1-4) provides:

❑ An abbreviated list of leak detector operating instructions to be used when the

operator is familiar with normal operation of the 947/948/960.

❑ Error codes and solutions.
❑ The leak detector's standard leak setting as measured at the factory.

1-8

Figure 1-4 Turret Door Instruction Label

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

1.5 Rear Panel Power Connection and Circuit Breakers

Figure 1-5 shows the rear power panel of the 947/948/960. Descriptions of the rear panel
elements follow the figure.

➂

➁

➃
➄

➅
➆

➀

Figure 1-5 Rear Power Panel

Rear panel power and circuit breakers:

➀ Power Inlet 115 VAC or 230 VAC power connection

(see “Power” on page 1-11)

➁ Power Switch/

Circuit Breaker

Mains power and Circuit breaker

➂ Rough Pump Circuit breaker for the Rough Pump
➃ Forepump Circuit breaker for the Forepump
➄ Turbo Pump Circuit breaker for the Turbo Pump
➅ Auxiliary Auxiliary Circuit breaker
➆ 24 V Power Supply 24 VDC Power Supply Circuit breaker

1-9

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

1.6 Service Pendant

The service pendant is used to set and display parameters for the 947/948/960 Leak
Detector. It is a handheld terminal with a 40-key keypad and a 20 character x 4 line backlit
LCD display (see Figure 1-6). The service pendant is stored in the turret and connects to the
947/948/960 using a six-foot cable that connects to an RS-232 serial port (J1, a 9-pin
D sub connector) located inside the lockable turret.

The service pendant is used to monitor and set up:

❑ Reject set point
❑ Crossover pressures
❑ Auto sequence parameters
❑ Ion Source parameters
❑ System setup parameters (such as the value of the calibrated leak)

Refer to “Using the Pendant for Parameter Setup” on page 3-17 for further information on
the operation of the service pendant.

J1

Turret

Service Pendant

1-10

Figure 1-6 Service Pendant

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

1.7 Installation Preparation

To prepare the 947/948/960 for operation:

❑ Have power and liquid nitrogen (948/960 only) available
❑ Check oil level of wet pumps
❑ Adhere to special installation requirements for a clean room (if required)
❑ Set up an appointment for Installation services (see page 1-12)

1.7.1 Power

CAUTION Varian strongly recommends the use of surge protection to

improve the immunity of the 947/948/960 leak detector against
unidirectional transients caused by the foll owing phenomena:

❑ Switching phenomena in the power network

❑ Faults in the power network

(e.g., switching of capacitor banks)

❑ Indirect lightning strikes

Mains supply:

❑ 115 VAC, 50/60 Hz, 20 A service, or
❑ 230 VAC, 50/60 Hz, 15 A service (must be ordered)

CAUTION Mains supply voltage fluctuations shall not exceed ±10% of the

nominal voltage.

Transient overvoltages shall not exceed values according to
Installation Categories (Overvol tage Categories) 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.

1-11

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

1.7.2 Liquid Nitrogen (Models 948/960 only)

The amount of liquid nitrogen needed to keep the cold trap operational is approximately
three liters per day (slightly more on initial startup).

NOTE Add liquid n itrogen to the trap only when the leak detector is

on and under vacuum.

1.7.3 Oil-Sealed Vacuum Pumps

The 947/948/960 is available with either dry or wet (oil-sealed) mechanical pumps. Units
built with oil-sealed pumps are shipped with the proper initial charge of oil, however, the
oil level should be checked after the pumps have been running for at least ten minutes. On
the front of each of the roughing and forepumps is an oil level sight glass. See “Rough Pump
and Forepump Oil Level Check (Oil-sealed Mechanical Pumps)” on page 4-31 for
instructions on how to check the oil level. The location of the mechanical pumps is shown
in Figure B-10 on page B-15. If you require more information, the pump manual you
received with the leak detector includes detailed instructions.

1.7.4 Special Installation Requirements

Additional services recommended for clean room use include:

Roughing/foreline
pump exhaust hose

Cooling fan air
exhaust hose

Dry vent gas Vent using the gas fitting on the back of the leak detector for the

Vent to the outside of the room using the KF-25 (ISO NW 25)
connection on the back of the leak detector. This reduces
particulate count and the helium background signal.

Connect to the optional 4" air duct that can be installed on the back
of the unit. This reduces the air flow turbulence around the
machine and particle emanation from the inside of the leak
detector cabinet into the clean room.

nitrogen, or other gas. By using a dry vent gas instead of room air,
moisture contact with vacuum-exposed surfaces is decreased,
resulting in better pump down performance.

1.7.5 Installation Services

Installation, operational checkout, and operating instructions for your 947/948/960 can be
provided by a qualified Varian Vacuum Technologies representative.

1-12

When your leak detector is unpacked and the required services are available, contact your
local Varian Vacuum Technologies office to arrange for field installation.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

1.8 Storage

If the leak detector is not used immediately, it can be stored as received without special
precautions. A dry, relatively dust-free area is preferred. The required environmental
conditions for storage are:

❑ 0% to 95% relative humidity, non-condensing
❑ –30 °F to 150 °F (–34 °C to +65 °C) ambient temperature

Refer to “Shutdown” on page 3-16 if the unit is to be stored after being used. Refer to
Section 3, “Operation” on page 3-1, of this manual for operating instructions.

1.9 Optional Rear Panel Interface Connections

Figure 1-7 shows the optional rear interface connection panel of the 947/948/960.
Descriptions of the rear panel connectors follow the figure.

➀

➃

Figure 1-7 Rear Panel Interface Connectors

The ports available on the rear panel for connection are:

➀ J122, Remote Box

Interface

➁ J120, Parallel

Interface

➂ J121, Parallel

Interface

➃ J123, RS232C

Interface

9-pin female D connector for the optional Universal
Remote Control

37-pin female D connector for the Discrete I/O for PLC control

25-pin female D connector for Discrete BCD and analog leak rate
output for PLC control

25-pin female D connector RS-232C serial port for host computer
control, to monitor and change parameters in the 947/948/960
Platform

➁

➂

The connections are used for in-line operation via control through a PLC. Refer to Section 2,
“Leak Detector Integration” and Section D, “Inputs and Outputs” on page D-1 for further
information.

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Section 2. Leak Detector Integration

Although Models 947/948/960 are considered stand-alone units, all the models can be
incorporated into a production line connected to a host computer or PLC.

This section details the setup and operation of Models 947/948/960 into a production line,
or for use as automated equipment, rather than stand-alone equipment.

2.1 Physical Considerations

An integrated 947/948/960 has the same physical considerations as a manually operated
unit.

2.2 Common Configuration

The 947/948/960 is ordered as needed from Varian Vacuum Technologies with the pumps
installed. If changes are needed for integration into a system, contact Varian Vacuum
Technologies Customer Service at 1-800-8VARIAN. The available pumps are listed in
Appendix E, “947/948 Specifications”.

2-1

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

In Figure 2-1 and Figure 2-2 on page 2-4, valves are designated by numbers in white circles
(

), other key parts of the vacuum system are designated by numbers in black circles (➊).

➀

The key parts are identified below the figure. The valve numbers are used in Table 2-1. The
valve name and type are defined in the upper portion of the table, the state of each valve
based system status is shown in the lower portion of each table.

❽

➃

➄

➅

➅

➀

❼

➈
➆

❶

❷

❾

➇

➁

❸

❹

Figure 2-1 947 Flow Diagram

❺

❶ Thermocouple Gauge (TC2) ❻ Thermocouple Gauge (TC1)

➂

❻

2-2

❷ Spectrometer Tube ❼ Test Port
❸ Turbo Pump ❽ Reservoir
❹ Forepump ❾ Standard Leak
❺ Rough Pump

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Table 2-1 serves two purposes. In the upper portion, the valve name and type are defined. In
the lower portion, Table 2-1 indicates the valve state (open or closed) in relation to the
system status for testing the 947/948/960. The following abbreviations are used in Table 2-1:

V=Vacuum

S=Solenoid

O=Open

C=Closed. All valves are normally closed.

Table 2-1 Valve Operation

Valve Name

Rough

Rough Valve Operator

Test

Test Valve Operator

Vent

VSVSS S S S S

Valve Type

Reservoir Rough

Gross Leak

Standard Test Leak

➀➄➁➅➂ ➃ ➆ ➇ ➈

Standard Leak Rough

Valve Number

System Status Valve State

Vent CCOOCCO
StartRough OCCCCCC
Gross Test O C C C O C C
Fine Test COCOCCO
Auto Cal COCOCOC
Hold and Fault C C C O C C O

Refer to Figure 2-2 on page 2-4 for valve locations.

2-3

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

In Figure 2-2, numbers in white circles designate the location of valves. Other key parts of
the vacuum system, represented by numbers in black circles, are identified after Figure 2-2.

❷

❶

❸

❽

➃➄➅

➈
➆

❿

❾

➇

❹❺

Figure 2-2 948 Flow Diagram

➁

➀

❼

➂

❻

❶ Thermocouple Gauge (TC2) ❻ The rm oc oup le Ga uge (TC1)
❷ Spectrometer Tube ❼ Test Port
❸ Turbo Pump ❽ Reservoir
❹ Forepump ❾ Standard Leak
❺ Rough Pump ❿ Nitrogen Cold Trap

2-4

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

In Figure 2-3, numbers in white circles designate the location of valves. Other key parts of
the vacuum system, represented by numbers in black circles, are identified after Figure 2-3.

1

❶

12

8

9

3

2

11

Figure 2-3 960 Flow Diagram

1 7

Reservoir Thermocouple Gauge (TC1)

10

4

❹

❷

5

6

❸

7

Rough Valve

❶

2 8

Turbo/Diffusion Pump Thermocouple (TC2)

3 9

Forepump System Pressure Gauge

4

Rough Pump Standard Leak

5

Manifold Nitrogen Cold Trap

6

Test Port Spec Tube

10

11

12

Test Valve

❷

Vent Valve

❸

Gross Leak Valve

❹

2-5

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

2.3 Electronic Considerations for the
Optional Rear Panel Interface

This section includes information necessary to interface the 947/948/960 with a PLC or a
host computer using either serial or parallel communications through the optional rear
panel interface via J120 Discrete I/O, J121 BCD Outputs and J123 Host Serial Port.

2.3.1 Discrete I/O J120 Inputs

The discrete I/O is used to control operations via a PLC. Table 2-2 provides the input
connections.

Table 2-2 J120 Input Connections

Pin on

J120

1 Ground return for J120 only
2 Reject Output Active High Leak rate signal is higher than reject

3 Stop 200 msec high pulse Unit goes to vent mode.
4 Start 200 msec high pulse Goes to fine test via rough gross modes.
6 Parallel Enable Active High Enables rear panel PLC Interface.
7 Zero 200 msec high pulse Begins Auto Zero routine.
9 Auto Cal 200 msec high pulse Begins Auto Calibrate.
10 Decrement 200 msec high pulse Decrements the exponent when in manual

11 Increment 200 msec high pulse Increments the exponent when in manual

12 Auto Range Active High Automatically changes the exponent to

Input Name Momentary or Level

set point.

ranging.

ranging.

keep the reading in range.

Description

14 Hold Places the system in Hold mode.
15 Filament Fault Active High Active when selected ion source

filament is non-functional.
16 Not Ready Active High Not ready to run – possible fault.
18 CAL OK Active High Active when last CALIBRATE successful.
19 Zeroing Active High Active when Auto Zeroing.
21 Calibrating Active High Active when Auto Cal.

2-6

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Table 2-2 J120 Input Connections (Continued)

Pin on

J120

23 Ready Active High Active when system is operating

25 Ground return for J120 only
27, 28 +24 VDC for Output Sourcing

Input Name Momentary or Level

(inverse of “Not Ready”).

Description

2.3.2 BCD J121 Output s

Table 2-3 provides the J121 output connections.

Table 2-3 J121 Output Summary

Pin on

J121

1, 2 Ground for J121
3 LSD A Active High BCD Leak Rate
4 LSD B Active High BCD Leak Rate

Signal Name Momentary

or Level

Description

5 LSD C Active High BCD Leak Rate
6 LSD D Active High BCD Leak Rate
7 MSD A Active High BCD Leak Rate
8 MSD B Active High BCD Leak Rate
9 MSD C Active High BCD Leak Rate
10 MSD D Active High BCD Leak Rate
11 LSD A Active High BCD Leak Rate
12 LSD B Active High BCD Leak Rate
13 LSD C Active High BCD Leak Rate
14 LSD D Active High BCD Leak Rate
15 MSD A Active High BCD Leak Rate
16 MSD B Active High BCD Leak Rate
17 MSD C Active High BCD Leak Rate
18 MSD D Active High BCD Leak Rate
20, 21 +24 VDC for Output Sourcing
24, 25 Ground for J121

2-7

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

2.3.3 Host Serial Port J123 Pinouts

The Host Serial Port is used to interface the 947/948/960 to a PLC or host computer via an
RS-232 connection. Table 2-4 provides details about the connection.

J123 connections are referenced to the chassis ground and are not isolated. Electrical
characteristics comply with EIA/TIA Standard EIA/TIA-232-E.

Table 2-4 J123 Pinout Summary

Pin on

J123

1 Shield Shield for J123, System Ground
2 RXD RS-232 Data
3 TXD RS-232 Data
4 CTS RS-232 Flow Control
5 RTS RS-232 Flow Control
6 DTR RS-232 Flow Control
7 Data Ground Signal Return for J123

20 DSR RS-232 Flow Control

Signal Name Description

2-8

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

2.4 Optional Interface Connections

Available ports for interface connection:

❑ Service RS-232 serial port for a service pendant or host computer

to monitor and change parameters in the 947/948/960 Platform
(J1 male 9-pin D connector in the Service compartment)

❑ RS-232 serial port for a high speed host computer or PLC to control, monitor, and

change parameters in the 947/948/960 Platform (J123 female 25-pin connector)

❑ Discrete I/O port for PLC control (J120 female 37-pin D connector)
❑ Discrete BCD and analog leak rate output port for PLC control

(J121 female 25-pin D connector)

❑ Optional Universal Remote Control Box port the (J122 female 9-pin D connector)

Refer to Section D, “Inputs and Outputs” on page D-1 for available rear panel ports,
pinouts, and signal designations.

The rear panel connectors are shown in Figure 2-4.

2.4.1 Grounding and Isolation

The service, remote, and rear panel RS-232 ports in the 947/948/960 are referenced to the
chassis ground and to the system ground.

Figure 2-4 Rear Panel

2-9

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

2.4.2 Setup

Parameters relating to the operation and performance of the 947/948/960 Platform are
stored in EPROM. These parameters can be viewed and changed via the service pendant or
rear serial ports.

A standard host computer with an RS-232 port, or PLC is used for connection to and control
of the rear panel serial port (J123). Only the pre-programmed Varian Vacuum Technologies
setup/service pendant is used for connection to and control of the service RS-232 port. The
keypad inputs and instructions (Section A, “Service Pendant Keypad Functions” on
page A-1) are used to determine certain internal operating parameters.

Some parameters are set when the system is assembled and tested. Other parameters are
changed when a gauge is changed or when the ion source or preamplifier is changed. Some
parameters are changed automatically during power up, or when functions such as the
Auto Cal, or Auto Zero run.

2.4.3 Dis crete I/O

J120 and J121 connectors contain the discrete I/O lines. This section provides the
information necessary to be able to use discrete I/Os.

The following items relate to the circuits shown in Figure 2-5:

❑ The discrete I/O lines are optically isolated and grouped by connector.
❑ J120 contains status and control inputs and outputs.
❑ J121 contains the BCD and analog voltage leak rate outputs.
❑ The power and return connections to J120 are isolated from J121 and from the

equipment and system grounds.

❑ The power and return connections for the BCD outputs in J121 are also isolated from

J120 and the equipment and system grounds.

2-10

Figure 2-5 Discrete Inputs/Outputs Isolated

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

If the I/O on J120 is used, then:

❑ +5 VDC to +24 VDC must be applied to J120, pins 27 and 28.

❑ The +5 VDC to +24 VDC return must be connected to J120, pins 1 and 25.

If the I/O on J121 is used, then:

❑ +5 VDC to +24 VDC must be applied to J121, pins 20 and 21.
❑ The +24 VDC return must be connected to J121, pins 1, 2, 24, and 25.

❑ The grounds between J120, J121, and chassis grounds are exclusive.

When using the discrete I/O, Allen-Bradley’s 1746-IBx and 1746-OBx (or equivalent)
modules for the SLC 500-series PLCs are recommended.

The analog leak rate output voltage on J121, pin 22, and return on J121, pin 23, have the
return referenced to the system ground.

The discrete inputs are:

❑ Opto-isolated with the negative side of the inputs combined and tied to the return

pins of the associated connector.

❑ The input voltage range is +5 VDC to +24 VDC.

❑ The maximum input current (at 24 VDC) drawn by each input is 7 mA.

The discrete outputs are:

❑ Opto-isolated Darlington transistor emitter followers with the collectors combined

and tied to the +24 VDC pins of the associated connector.

❑ The maximum current that can be drawn from each output is 20 mA.

❑ The output voltage supply range is +5 VDC to +24 VDC.

NOTE When operating the 947/948/960 from the d iscrete I/O, it is

necessary to make the PARALLEL ENABLE (J 120 pin 6) active.
This allows the controller to accept commands from the other
discrete I/O inputs. Making PARALLEL ENABLE active also
disall ow s any changes to the operating parameters through the
front panel or serial ports (service pendant). Requests for
changes made through the serial ports are responded to with
cant.

2-11

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

2.5 Operation using the Optional Rear Panel Interface

Once setup is complete and the 947/948/960 is warmed up, operation can be turned over
to the discrete I/O by asserting the PARALLEL ENABLE input (J120 pin 6). Operations can be
monitored using the front panel display, or via a PLC.

2.5.1 Parallel Enable

The PARALLEL ENABLE input turns control of the 947/948/960 over to the discrete I/O
for efficient operation. Once PARALLEL ENABLE is asserted, operations can be monitored
using the host serial port, but most parameter values cannot be changed. If a command is

issued that is not allowed once PARALLEL ENABLE is asserted, the system response is cant.

See Section C, “Communications Protocol” on page C-1.

Operations can be monitored on the front panel display, but the parameter values cannot be
changed using the front panel. See Section D, “Inputs and Outputs” on page D-1.

To remove control from the discrete I/O, you must de-assert PARALLEL ENABLE
(J120 pin 6).

NOTE Control remains with the discrete I/O, even if the leak detector

is shut down while PARALLEL ENABLE is asserted.

2-12

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Section 3. Operation

To obtain accurate readings using the 947/948/960 leak detectors, follow the operational
procedures listed in this section. The 947/948/960 measure the leak rate in atm cc/sec.

The procedures explain how to:

❑ Start and warm up the 947/948/960.
❑ Calibrate the 947/948/960.
❑ Set the parameters to obtain accurate readings.
❑ Operate the 947/948/960 to obtain precision leak readings using helium.
❑ Put the 947/948/960 in STANDBY mode, and/or shut it down entirely for

maintenance or storage.

Parameter setup using the service pendant applies to both stand-alone (manual) and in-line
production operation.

3.1 Front Panel LED Indicators and Controls

Figure 3-1 shows the LED indicators and controls on the front panel (right hand side) of the
947/948/960 turret. The buttons are defined in “Front Panel Controls and Indicators” on
page 1-6.

Figure 3-1 Front Panel LED Indicators and Controls

3-1

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

During operation, the LED functions are illuminated to indicate the operation being
performed. The definitions of the operations are as follows:

VENT Illuminates when the vent valve is open. The LED is off when the

valve is closed.

START Illuminates when the START button is pushed. Goes off one

second after the TEST LED illuminates, or immediately when the
VENT, HOLD, or NOT READY LEDs illuminate.

TEST Illuminates when 947/948/960 is in test mode; either the gross leak

valve or the test valve is open. Otherwise, the LED is off.

ZERO Illuminates when the ZERO button is pushed or when the auto-zero

sequence is performed as part of the auto-calibrate sequence. Goes
off one second after the auto-zero sequence is completed or if the
leak detector goes into a not-ready condition. The ZERO LED
flashes when the signal falls below zero. The ZERO LED also
flashes during startup when the system is nulling the preamplifier.

REJECT Illuminates when the reject function is on and when the leak rate

reading exceeds the selected set point. Goes off when the leak rate
falls below the set point.

HOLD Illuminates if the machine is in the HOLD mode with the test and

roughing valves closed. The HOLD mode is selected by momen­tarily pressing the VENT button if the machine is in TEST. When in
HOLD, pressing either the START or VENT button launches the
next operation.

NOT READY Illuminates whenever a not-ready condition exists. The particular

error condition code, c0 through c9, is displayed on the RANGE
DISPLAY. See Table 3-1 on page 3-11 for information on the error
codes.

AUTO CAL If the leak detector is in TEST mode, illuminates when the AUTO

CAL button is pushed, disabling all other front panel push buttons,
including START and VENT. AUTO CAL is only functional when
the leak detector is in TEST mode. The machine returns to TEST
mode at completion of the AUTO CAL routine.

STD LEAK Illuminates when the standard leak test valve is opened. This

occurs when the STD LEAK button is pushed or during the auto-cal­ibrate function. Goes off when the standard leak test valve is closed
by pressing the STD LEAK button.

SERVICE Not used.

3-2

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

3.2 Initial System Parameter Setup

The 947/948/960 performs functions and tests based upon parameter values. Some
parameters are entered and set when the system is assembled and tested. Some parameters
are calculated and change automatically during power up, Calibrate, or Zero functions.
Other parameters are changed when a change is made to the physical system, such as when
a thermocouple gauge, ion source or preamplifier is changed. These parameters are set as a
function of the physical configuration and sensitivity needs.

Several parameters relating to the operation and performance are stored in EPROM in the
control unit. The information for these parameters is not lost when the power is shut down.
Parameters can be viewed and changed through commands entered via the service pendant
or host computer.

“Parameters and Operating Modes” on page 3-3 explains the parameters and what happens
during the related function.

3.2.1 Parameters and Operating Modes

The parameters and operating modes work together to perform leak detection, and the
parameters that are entered determine the type of test and sensitivity of testing performed.
The discussion below includes an explanation of what the parameter or function means. For
additional information on how to set a parameter or select a function, refer to “Start-Up” on
page 3-8 and Section A, “Service Pendant Keypad Functions” on page A-1, or if the optional
rear panel interface is installed, Section C, “Communications Protocol” on page C-1.

RANGE The 947/948/960 automatically sets the Range equal to the expo-

nent of the least sensitive range of the leak detector, depending on
the sensitivity of the vacuum system.

AUTO-RANGE and
MANUAL RANGE

Auto-Ranging causes the leak detector to automatically change the
leak rate exponent and mode to keep the leak rate reading on
scale.

Manual Range is used to force the 947/948/960 to display a leak
rate in only one decade (the exponent never changes). This feature
is useful when the test operator is only concerned with monitoring
the leak rate measurement within a single decade. Set the Leak
Rate Range Mode to MAN and use the SMALLER or LARGER
buttons to change the range.

3-3

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

RANGE STOP The RANGE STOP feature configures the 947/948/960 so that it

only auto-ranges down to the pre-selected decade entered in the
range stop variable field. For example, if RANGE STOP is enabled

and set to −07, then the most sensitive range that the leak detector

displays is 10

This feature is useful when a product specification is more than one
decade less stringent than the sensitivity of the leak detection sys­tem as it is configured. If the configured system is capable of
detecting 10

−7

10

atm cc/sec range, then setting the RANGE STOP to −08

reduces the test cycle time by eliminating the need for the leak
detector to reach its most sensitive decade (10
cycle.

AUTO CAL Used to perform an automated calibration based upon the parame-

ters set. Calibration is compared to a known internal leak.

To perform an automated calibration, press the AUTO CAL button,
or assert calibrate input via the serial port or optional discrete I/O.

−7

.

−9

atm cc/sec but the test specification is only in the

−9

) during each test

CALIBRATED
LEAK VALUE

The 947/948/960 is shipped from the factory with a calibrated leak.
Its value is noted on the turret of the leak detector and on the Cal
Leak Certification. When a calibration is performed, the system
compares the leak rate signal with the stored value. The tuning pro­cess involves independently scanning the ion source chamber volt­age and the variable focus voltage, and optimizing each value for a
maximum helium signal. Once the tuning process is complete, the
system gain is adjusted to bring the leak detector into calibration.

ZERO The ZERO function reads the background leak rate signal, stores

the reading in memory, and then resets the zero reference point.
Subsequent actual test measurements include both helium from the
real leak and helium from background conditions, however, the
recorded background signal from the measurement is subtracted
and the resultant real leak rate is displayed. To perform a ZERO
function, press the ZERO button, or assert ZERO input via serial
port or optional discrete I/O.

NOTE Performing the ZERO function while introducing helium to the

test ob ject can re sult in the sup p r ession of a real leak. Only use
the ZERO function after t he helium source has been removed.

3-4

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

REJECT SET POINTS The REJECT SET POINTS are used to alert the operator that a mea-

sured leak rate has exceeded the set value. There are four set points
available. Each set point must be enabled before they are opera­tional. Conversely, each must be disabled to stop its operation.
Only one set point can be active at any given time.

AUDIO VOLUME The AUDIO VOLUME control is used to activate the audio tone

from the turret. The audio tone frequency increases as the size of
the measured leak increases. The audio volume control is located
on the turret.

BAR GRAPH DISPLAY The 50-segment bar graph display on the front control panel repre-

sents the mantissa value of the leak rate, spanning from 0 to 10.
The scale shows above the bar graph. The numerical display,
located to the far right of the bar graph, displays the leak rate expo­nent value in atm cc/sec.

LINEAR VS LOG
OUTPUT

AUTO-SEQUENCER Provides clear accept/reject signals and allows programming for

Configure the analog output voltage to the optional I/O port on the
back of the unit. The options for output are linear or logarithmic at
2 VDC per decade or 3 VDC per decade.

roughing, testing, and cycling times. Auto sequencer provides the
ability to set up the 947/948/960 so that it automatically runs
through a complete test cycle (START/ROUGH/TEST/VENT), pass­ing or failing the test part per the test specification entered by the
user. The auto sequencer set-up controls include test object rough
time, test time, and auto sequencer on/off. A Pass or Fail condition
is determined based upon the reject set point selected by the user
and/or achievement of the pressure transfer set points within the
period of time specified in Rough Time.

The auto sequencer pass or fail leak rate value is selected through
the Reject Set Point. The pass/fail criterion is based on the reject set
point that is enabled (ON). If more than one set point is enabled,
then the pass/fail criterion is based on the most stringent reject set
point value.

3-5

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

A Pass condition is indicated by the system reverting to the VENT
mode upon completion of the test cycle. A fail condition results in
REJECT being displayed in the LED display area, and a reject set
point activation upon completion of the test cycle. A Fail condition
is also indicated by the system reverting to the HOLD mode, and
all operating buttons being disabled except VENT. The status of
the reject set points is available at the optional I/O communications
port (host computer) and upon inquiry through the service pendant
(Section A, “Service Pendant Keypad Functions” on page A-1).

Upon the completion of an automated test cycle, the 947/948/960
captures the leak rate signal measured just prior to the end of the
automated test cycle. This leak rate is displayed and held at the
analog output communications port until the next test cycle is initi­ated. This allows the end user to record the actual leak rate value
for each test object.

ROUGH TIME The ROUGH TIME variable determines the amount of time that the

leak detector is allowed to evacuate the test object to the tolerable
test transfer pressure. In AUTO SEQUENCER mode, the
947/948/960 transfers into test as soon as the tolerable transfer
pressure is met. It does not wait for the total rough time allotted if it
is not required. If the tolerable test transfer pressure is not achieved
within the pre-selected rough time, the system aborts the cycle and
goes into HOLD mode.

The ROUGH TIME value can be determined empirically and
should reflect the typical time required to rough the test object to
the tolerable test pressure. Failure to achieve the tolerable test pres­sure within the pre-selected rough time is an indication of a gross
leak in the test object or test fixturing or that the time allowed was
insufficient.

3-6

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

TEST TIME The TEST TIME variable determines the amount of time that the

leak detector remains in test before it compares the measured leak
rate with the selected reject set point. Sufficient time must be
allowed for the leak rate reading to stabilize before the system
makes a pass/fail decision. This is a function of the part configura­tion and the leak rate specification. In AUTO SEQUENCER mode,
the 947/948/960 remains in test for the entire duration of the prese­lected test time.

FINE TEST MODE When FINE TEST (normal operating mode) is used, the leak detec-

tor automatically tests for gross leaks and then transfers into fine
test if no gross leaks are detected.

GROSS TEST ONLY
(HOLDING IN GROSS
FOR LARGE LEAKS)

TRANSFER POINTS Set the test transfer pressures for each testing mode.

GROSS LEAK XFER The GROSS LEAK XFER set point determines the test pressure cross

The 947/948/960 Leak Detector uses the Contra-Flow system,
which has a gross leak manifold, allowing testing at higher inlet
pressure with reduced sensitivity.

When TRANSFER TO FINE TEST is set to NO, the leak detector
does not transfer into FINE TEST mode. This feature is useful for
qualifying parts that have an unusually high rate of gross leak fail­ures prior to fine leak testing.

The transfer pressure settings can be adjusted to lower values for
specific applications. The 947/948/960 has pre-programmed upper
transfer pressure limits that are slightly greater than the default set­tings. These limits prevent the operator from inadvertently setting
the 947/948/960 to transfer into test at too high a pressure, resulting
in excessive spectrometer tube contamination or ion source fila­ment failure.

over point at which the 947/948/960 transfers into the GROSS
LEAK TEST mode. In the GROSS LEAK TEST mode, the majority of
the sampled gas is pumped away through the dedicated roughing
pump while a small sample of gas is introduced into the leak detec­tor through a throttle valve.

3-7

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

3.3 Start-Up

To operate the 947/948/960, you need:

❑ Test fixtures appropriate to the unit under test
❑ Helium tank with spray gun or hook up for auto test (Helium for the 948/960)

Figure 3-2 shows the important 947/948/960 operation controls for start up and power. For
circuit breaker descriptions, refer to “Rear Panel Power Connection and Circuit Breakers”
on page 1-9.

➅

➁

➂

➃➄

45

➀

➆

3-8

Figure 3-2 Start-up Controls

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

➀ Power

switch/Circuit
breaker

➁ Rough pump

switch

Main power switch and circuit breaker.

Powers the rough pump.

➂ Detector switch Powers the backing pump and high vacuum pump.
➃ START button Starts the 947/948/960 testing routine. Press and hold for 1 second

to engage.

➄ VENT button Opens the vent valve so test pieces can be removed or attached to

the detector. Press and hold for 1 second to engage.

NOTE If the VENT button is pressed for less than one second, the leak

detector moves to HOLD.

➅➅ Test Port The unit under test is connected to this port using a test fixture, or a

plug is inserted for storage.

➆ AC Power Input View of back of unit.

Refer to Figure 3-2 and follow the start up procedure, listed in the next Section, and in
“Calibration and Sensitivity Checks” on page 3-11 procedure to put the 947/948/960 in a

Ready for Operation state from the All Systems off condition.

3-9

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

3.3.1 Startup Procedure

To perform the start-up procedure:

1. Locate the main power switch/circuit breaker
turn it on.

2. Turn on the Rough

3. Turn on the Detector

4. Models 948/960 only: When the system pressure bar graph drops into the green range
(see Figure 1-3 on page 1-6), fill the cold trap with liquid nitrogen.

WARNING Liquid nitrogen causes burns upon contact. Use appropriate

Refill the cold trap as required to prevent it from thawing in the vacuum system. The
trap needs to be filled approximately every 14 hours. Monitor the level and fill more
often if necessary.

CAUTION If the cold trap in the 948/960 is allowed to empty of liquid and

➁ pump switch.

➂ switch.

protective devices, including heavy loose gloves and eye or
face shields.

thaw in the vacuum system, sp ectrometer tube contamination
occurs resulting in unstable leak rate detection. Attempts to
perform an automated calibration can also result in error
conditions (codes c6, c7, and c8). Filling the trap comp letely
keeps the trap operational up to 14 hours. Before refilling is
required, refer to Section 4, “Maintenance” on page 4-1 for the
cold trap cleaning procedure.

➀ on the back of the lower cabinet and

3-10

5. Wait 30 minutes for the 947/948/960 to warm up to operating temperature.

6. The detector is now on and ready for normal operation.

NOTE Perform the calibration and sensitivity check before taking

readings with the 947/948/960.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

3.4 Calibration and Sensitivity Checks

At the beginning of each workday or shift, or as conditions require, verify 947/948/960
integrity by performing the Calibration and Sensitivity Check procedure. Compliance with

this procedure prepare your detector for normal daily operation. If the NOT READY LED

comes on during calibration, refer to the condition code that appears in the leak rate
exponent display shown in Figure 3-3.

Figure 3-3 Exponent Display with Condition Code Indicated

➀ Condition Code Exponent area with condition code displayed.

Table 3-1 lists the Not Ready condition codes and the action to take to correct the error
condition.

➀

Table 3-1 NOT READY Condition Codes

Code Problem Solution

c0

c2 Rough pump is off Turn on the rough pump.

c4

c5

c6

c7

Amplifier Offset is
out of range

No emission Select the other ion source filament. Replace ion source if necessary.

Auto calibrate function is
out of range

Auto tune function is
out of range

Auto Zero function is
out of range

Notify Varian Vacuum Technologies Customer Service. Spectrometer
Tube Amplifier needs service.

Refer to Section 4, “Maintenance” on page 4-1.
Notify Varian Vacuum Technologies Customer Service. Leak detector

requires maintenance.
Tap the AUTO CAL button. (A brief tap may clear this code to allow

the leak detector to operate.) If this clears c6 then the leak detector is
operable. If c5 appears with c6 it is the priority conditio n code .

VENT to clear.

Press
NOTE: A c6 condition code means that maintenance of the leak

detector may soon be necessary. Notify Varian Vacuum Technologies
Customer Service at 1-800-8VARIAN.

Notify Varian Vacuum Technologies Customer Service. Leak detector
requires maintenance.

c8

c9

Power interruption Perform a Calibration and Sensitivity Check. This condition code may

be accompanied by an intermittent c9 indication.

System pressure is
too high

Check for vacuum leaks. Refer to Section 4, “Maintenance” on
page 4-1.

3-11

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

3.4.1 Calibration and Sensitivity Checks

To perform calibration and sensitivity checks:

1. Warm up the 947/948/960 for 30 minutes.

2. Place the test port plug in the test port opening

➅. Refer to Figure 3-2 on page 3-8.

3. Set the Transfer switch to AUTO.

4. Set the Mode switch to AUTO. The VENT LED should illuminate.

5. Press the START button.

❑ The VENT LED goes off.
❑ The START LED illuminates.
❑ The TEST LED illuminates when test pressure drops.
❑ The START LED goes off (1 second) after TEST LED illuminates.
❑ The Leak Rate range display goes to most sensitive range.

6. Press the ZERO button. The ZERO LED turns on briefly.

7. Be sure the TEST LED is on, and press the STD LEAK button.

The STD LEAK LED illuminates and the LEAK RATE display should be equal to the
internal calibrated leak as marked inside the hinged top cover.

8. Press STD LEAK again to turn it off and continue testing.

The LEAK RATE display should return to the most sensitive decade. If the leak rate
reading is not within 20% of the number on the calibrated leak label, perform an AUTO
CAL.

3-12

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

9. Be sure the TEST LED is on, and press the AUTO CAL button.

Do not continue if a condition code is displayed. Consult the NOT READY Condition

Code Chart Table 3-1 on page 3-11 and follow instructions.

❑ The STD LEAK LED is on; AUTO CAL is also on.
❑ The LEAK RATE display mantissa and exponent values change as a function of auto

tuning.

❑ The STD LEAK LED goes off. The LEAK RATE display changes again and

approximately 20 seconds later, the ZERO LED illuminates to signify the zero
procedure is operating, then it goes off.

❑ The AUTO CAL LED goes off, and the HOLD LED illuminates.
❑ The LEAK RATE display mantissa is zero (one LED bar lit) on the most sensitive

LEAK RATE range exponent.

Calibration is complete when the AUTO CAL LED goes out.

10. Recheck STD LEAK reading (Steps 7 and 8).

11. Press either the START or VENT button to continue operation following the AUTO CAL

routine.

3.5 Operating Procedures

The testing parameters vary from one manufacturing environment to another. Section G,
“Leak Detection Theory” on page G-1 describes the conditions under which the
947/948/960 Leak Detectors can be utilized. There are many applications. A
Varian Vacuum Technologies representative is always available for technical assistance.

Whatever the leak detection situation, testing is accomplished in one of the two operating
procedures:

❑ “Auto Ranging” on page 3-14
❑ “Manual Ranging” on page 3-15

Requirements:

❑ After shutdown of a leak detector, a complete startup is necessary as outlined in

Start-up Procedure.

❑ Verify the integrity of the leak detector with the Calibration and Sensitivity Checks

Procedure on a daily basis or as necessary.

3-13

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

3.5.1 Auto Ranging

To use auto ranging for outside-in testing:

1. Press the VENT button. Securely attach the new unit under test to the test port while the
947/948/960 is in VENT mode.

❑ The TEST LED goes off.
❑ The VENT LED illuminates.

2. Select the AUTO (Figure 3-4) position of the AUTO/MAN MODE switch in the Leak
Rate Range section.

Figure 3-4 Location of AUTO/MAN MODE Switch

3. Press the START button.

❑ The VENT LED goes off and one second later, the START LED illuminates.
❑ The TEST LED illuminates.
❑ The START LED goes out.
❑ The LEAK RATE range exponent goes to the most appropriate range.

4. Introduce helium to the unit under test.

The 947/948/960 automatically traces the under test helium signal up range through the
Reject Set Point. If larger than the pre-set Reject value, the leak rate signal reads this
maximum level. The REJECT LED lights up.

3-14

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

5. Press and hold the VENT button approximately 1 second until the 947/948/960 is in

VENT mode.

❑ Test LED goes off.
❑ Vent LED illuminates.

6. Remove the unit under test from the test port.

❑ VENT LED is on.

Auto ranging procedure is complete.

3.5.2 Manual Ranging

Manual ranging is used when the range of the failure level for the part under test is known.

To range manually:

1. Press the VENT button.

❑ TEST LED goes off.
❑ VENT LED illuminates.

2. Select the MAN position of the AUTO/MAN MODE switch in the Leak Rate Range

section.

3. Press the SMALLER or LARGER button to select the exponent of the leak rate range to

which you want to test.

4. Securely attach the new unit under test to the test port while the 947/948/960 is in

VENT mode.

5. Press the START button.

❑ The VENT LED goes off.
❑ The START and TEST LEDs illuminate a second later.
❑ The START LED turns off and the LED Rate Range (exponent) displays at the

selected range.

6. Introduce helium to the item under test. The leak detector automatically traces the

helium signal within the selected range. If larger than the pre-set Reject value, the leak
rate signal reads the maximum level and the Reject LED illuminates.

3-15

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

7. Press and hold the VENT button for approximately 1 second until the unit switches to
the VENT mode.

❑ The TEST LED turns off.
❑ The VENT LED illuminates.

8. Remove the tested part from the test port.

The Leak test is now complete.

3.6 Standby

When continued use of 947/948/960 is not anticipated, STANDBY mode, a partial
shutdown, can be used to save energy. To put the 947/948/960 into STANDBY mode:

NOTE If the VENT button is pressed for less than one second, the leak

detector moves to HOLD.

1. Press the VENT button and hold it until the Vent LED comes on.

2. Place the Rough pump power switch in the OFF position.

3. Turn the Rough pump switch breaker to the ON position to return the Leak Detector to
the READY FOR OPERATION mode.

3.7 Shutdown

Complete shutdown for a move or temporary storage is accomplished by the following
shutdown procedure:

1. Place the test port plug securely in the test port.

2. Turn the ROUGH PUMP switch OFF.

3. Turn DETECTOR switch OFF.

4. Turn the Power switch/circuit breaker OFF on back of cabinet.

NOTE When the unit is returned t o Read y for Opera tion from Stand by,

the warmup periods do not apply.

3-16

5. For the 948/960 only, empty the cold trap.

See “Liquid Nitrogen Cold Trap (Models 948/960 only)” on page 4-10 for the cleaning
procedure.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

3.8 Using the Pendant for Parameter Setup

The service pendant is stored in the turret and is connected to Models 947/948/960 at
J1 in the turret for parameter changes, monitoring, or diagnostics. The pendant must be
connected to the 947/948/960 to operate any of the functions. Refer to Section G, “Leak
Detection Theory” for information on turret connectors.

The service pendant is used to set up and monitor:

❑ Reject set point
❑ Crossover pressures
❑ Auto sequence parameters
❑ Ion Source parameters
❑ System setup parameters (such as the value of the calibrated leak).

When the pendant is powered by the 947/948/960, the display indicates the model to
which the leak detector is connected. The keyboard is laid out in function keys and numeric
keys. See Figure 3-5.

Figure 3-5 Service Pendant Keypad

3-17

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Several parameters relating to the operation and performance of the 947/948/960 Platform
are stored in EPROM. These parameters are viewed and changed via the service or rear
serial ports. Some parameters are set when the system is assembled and tested. Other
parameters should be changed when a gauge is changed or when the ion source or
preamplifier is changed. Some parameters are changed automatically during power up,
Auto Cal, or Auto Zero functions. See Section G, “Leak Detection Theory” on page G-1 for
details.

3.9 Optional Discrete I/O

To use the optional discrete I/O connections, connect to J120 and J121 on the rear panel.
Refer to Section D, “Inputs and Outputs” on page D-1 for detailed information.

When operating the 947/948/960 from the optional discrete I/O, it is necessary to make the
PARALLEL ENABLE (J120 pin 6) active. This allows the leak detector to accept commands
from the other discrete I/O inputs. Making PARALLEL ENABLE active also disallows any
changes to the operating parameters through the serial port, the service pendant, or the front
panel. Requests for changes made through the serial port would be responded to by cant.

3-18

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Section 4. Maintenance

Like other sensitive test equipment, a mass spectrometer leak detector requires periodic
maintenance to ensure continued reliable operation. After prolonged use, the leak detector
accumulates contaminants from even the cleanest of products tested. These contaminants
eventually impair operation. A thorough disassembly and cleaning of the entire vacuum
system, which includes the cal leak valve block and spectrometer tube, restores normal
operation. For heavy production use, more frequent overhauls are needed. In most cases,
this work is done by user maintenance personnel, but it may also be done by Varian
Vacuum Technologies under the terms of a service contract.

This maintenance section does not cover overhaul of the entire vacuum system. It does
cover daily maintenance and as-required maintenance.

Important Reminders

Heed the following notes, cautions, and warnings when performing maintenance.

WARNING Disconnect power from the 947/948/960 before perfo rming any

maintenance procedure that requires physically disconnecting
any part of the system.

WARNING The mechanical components of leak detectors are typically

cleaned with alcohol or other solvents. When heated, sprayed,
or exposed to high-tem per a ture equipment, thes e s olven ts
become flammable and explosive, causing serious injury or
death. Do not use near a high-temperature source. Ventilate
the work area with a blower and use solvents only in large,
well-ventilated rooms.

Alcohol and other solvents are irritants, narcotics, depressants,
and/or carcinogens. Their inhalation and/or ingestion may
produce serious effect s. Prolonged or continued contact with
the skin results in absorption through the skin and moderate
toxicity. Always ensure that cleaning operations are carried out
in large, well-ventilated rooms. Wear eyeshades, gloves, and
protective clothing.

WARNING The preamplifier i s a static sensitive device. Wear a grounding

device whil e the preamplifier is being handled.

4-1

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Cleanliness is vital when servicing the leak detector or any vacuum equipment.
The following are especially important in the servicing of leak detectors:

CAUTION Do not use silicone oil or silicone grease.

Use powder-free butyl or polycarbonate gloves to prevent skin
oils from getting on vacuum surfaces.

Do not clean any aluminum parts with Alconox. Alconox is not
compatible with aluminum and will cause damage.

NOTE Normally, the use o f vacuum greas e is unnecessary. If it must be

used, use it sparingly and avoid silicone types. Apiezon L
grease is recommended (Varian P/N 695400004).

When removing, checking, or replacing O-rings:

CAUTION Remove O-rings carefully with your fingers. Do not use metal

tools which could scratch the sealing surfaces.

Do not use alcohol, methanol, or other solvents on O-rings.
To do so causes d et erioration and re du ces t heir ability to hold a
vacuum.

Wipe all O-rings clean with a lint-free cloth before installation
to ensure that no foreign matter is present to impair the seal.
Do not use grease or other substances on O-rings that come in
contact with the spectrometer tube.

4-2

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

Due to the effective cleaning nature of VacuSolv solvent and its residue-free properties,
Varian Vacuum Technologies’ Component and Spectrometer Tube Cleaning Kit (Varian
P/N 670029096), used in accordance with the kit instructions, is recommended for cleaning
the spectrometer tube components. The kit can also be used for fine cleaning of other parts
in the leak detector vacuum system such as valves and fittings. No rinsing steps or
high-temperature drying is required following a cleaning with VacuSolv. Although
appropriate precautions are advised, VacuSolv is compatible with most materials and does
not contain toxic chemicals or CFCs (chlorofluorocarbons).

The scheduled maintenance functions in this section are grouped by recommended
frequency, as shown in Table 4-1, based on assumed everyday use. The 947/948/960
operates at its peak when maintenance (preventive) procedures are performed at their
scheduled intervals. Read the pump manuals that came with your 947/948/960 leak
detector for more complete maintenance information specific to the pumps. See “Spare
Parts” on page 4-34 for more information.

The 947/948/960 must be calibrated to verify sensitivity at least once a day. However, other
functions may be carried out more or less often, depending on the frequency of use.

x

Table 4-1 Scheduled Maintenance

Description Daily 12 Months Refer to

Calibration check

Re-calibrate the internal calibrated leak

Spectrometer tube overhaul

Filter replacement

●

●

●

●

“Calibration Check” on page 4-5

“Re-calibrate the Internal Calibrated Leak” on
page 4-7

“Spectrometer Tube Overhaul” on page 4-11

“Air Filter” on page 4-20

4-3

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

On-demand maintenance functions are listed in Table 4-2.

Table 4-2 As-Required Maintenance

Most Common Symptom Refer to

Trap almost empty, nearly 14 hours without a refill. “Liquid Nitrogen Cold Trap (Models 948/960 only)” on

page 4-10
Preamplifier failure. “Spectrometer Tube Exchange” on page 4-21
Loss of sensitivity, increase in background, high ion

voltage (> 300 VDC), required to tune the leak
detector.

Filament failure (as soon as convenient after second
filament is in use).

Pump running rough, vacuum not attainable. “Rough Pump and Forepump Oil Level Check

TC1 gauge needs replacement as indicated by the
fact that:

❑ Test port pressure does not come down

(atmosphere indication) when start button is
pushed (test mode) assuming no leaks.

❑ Test port pressure comes down slightly

(1/4 to 1/2 scale) when test port plug is installed,
once again assuming no leaks can be heard or
seen (gross leak).

TC2 gauge needs replacement as indicated by the
fact that:

❑ Spectrometer tube pressure shows high pressure

(full scale indication). System will not activate the
ion source filament due to a false high pressure
indication, a failed turbo pump, or a leak in the
spectrometer tube.

❑ Spectrometer tube pressure comes down slightly

(1/4 to 1/2 scale) after the leak detector has been
warmed up for 30 minutes.

“Spectrometer Tube Overhaul” on page 4-11

“Replacing the Ion Source” on page B-6

(Oil-sealed Mechanical Pumps)” on page 4-31

“TC1 and TC2 Gauge Replacement and Calibration”

on page 4-23

Unsatisfactory condition on visual inspection.
The frequency of port cleaning depends on the

application.

4-4

“Cleaning the Test Port” on page 4-32

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.1 Daily Maintenance

4.1.1 Calibration Check

To perform a calibration check:

1. Press the STD LEAK button.

2. Compare the value displayed on the 947/948/960 to the value of the known calibrated
leak listed on the label on the top of the turret.

Refer to Figure 1-1 on page 1-2 for the location of the label.

3. If the values do not match, press the AUTO CAL button and then repeat step 1.

Detailed instructions for sensitivity and calibration checks are included in “Calibration and
Sensitivity Checks” on page 3-11. If specifications cannot be met, Manual Tuning is
required. Manual Tuning is restricted to trained, qualified customer technicians. Contact
Varian Vacuum Technologies Customer Service at 1-800-8VARIAN if manual tuning is
necessary.

4.1.1.1 Leak Checking

The accuracy, reliability, and stability of any mass spectrometer leak detector depends on
the leak-free integrity of its own vacuum system. Inherent helium background and its effect
on sensitivity demands elimination of all detectable leaks. If performance degrades during
operation or after some part of the vacuum system is opened for service, a methodical leak
check eliminates the possibility of a leak as the cause.

NOTE T o ensure reliable testing, after servicing any part of t he vacuum

system, the 947/948/960 must be leak checked again.

4-5

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.1.1.2 General Suggestions for Leak Checking

The following suggestions apply whether leak checking components, systems, or the leak
detector itself:

1. When spraying suspected leak locations:

❑ Always apply helium sparingly.
❑ Since helium rises, start at the highest points first.
❑ Apply helium downstream from the source of a draft first, or deflect the draft until

leak checks are completed.

2. If vent grooves exist at flanges or other assembled seals, apply helium to these points
(rather than spraying a general area) to:

❑ Obtain the most positive response.
❑ Minimize the use of helium.
❑ Save time in checking.

3. Locate and repair large leaks before attempting to locate extremely small leaks.

4. Limit the search to a general area of the test piece by isolation methods to shorten the
time required to locate both large and small leaks. Isolation methods include:

❑ Bagging
❑ Masking
❑ Shielding with tape, plastic film or duct seal (if applied properly)

5. Use only enough helium to reach the leaks. Do not flood the area.

4-6

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2 Yearly Maintenance

4.2.1 Replacing the Calibrated Leak

4.2.2 Re-calibrate the Internal Calibrated Leak

Helium calibrated leaks typically degrade at 3 percent per year. The calibrated leak
supplied with your 947/948/960 must be checked at least once a year to ensure it is at the
value stated on its label. Failure to check the leak could result in unreliable testing. You can
arrange for testing and re-calibration at a lab of your choice.

Varian Vacuum Technologies provides NIST-traceable calibrated leak testing and
verification services. Contact Customer Service at 1 (800) 8VARIAN to arrange for
re-calibration.

4.2.2.1 Removing the Internal Calibrated Leak

The calibrated leak is located in the main cabinet area near the top of the leak detector as
shown in Figure 4-1.

Thumb Screw

Rear of Leak Detector

Figure 4-1 Location of the Calibrated Leak

4-7

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

To remove the internal calibrated leak:

1. Disconnect the mains power supply and make sure all pumps are off.

WARNING Disconnect power from the 947/948/960 before perfo rming any

maintenance procedure that requires physically disconnecting
any part of the system.

CAUTION Models 948/960 only: Remove, empty, and clean the cold trap

whenever pow e r is remo ve d. Re fe r to “Liquid Nitro g en C o ld
Trap (Models 948/960 only)” on page 4-10.

2. Remove the top panel of the 947/948/960.

3. Vent the turbo by turning the knurled nut on the turbo pump ¼ turn clockwise and then
close it.

4. Loosen the thumbscrew on the top of the cross bar by turning it clockwise, but do not
remove it completely.

5. Grasp the calibrated leak and pull it straight back to remove it.

6. If the O-ring and centering ring do not come out with the calibrated leak, reach into the
cavity and remove them.

CAUTION Remove O-rings carefully with your fingers. Do not use metal

tools for this task. This prevents scratching of any sealing
surfaces.

4-8

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.2.2 Replacing the Internal Calibrated Leak

To replace the calibrated leak:

1. Wipe the O-ring with a lint-free cloth to ensure that no foreign matter is present.

CAUTION Varian recommends replacing all used O-rings.

Do not use grease or other substance on O-rings that come in
contact with t h e spectrometer tube.

If applicable, apply a small amount of Apiezon



L grease and

wipe the O-rings “shiny” dry.

Do not use alcohol, methanol or other solvents on O-rings. To
do so causes deterioration and reduces their ability to hold a
vacuum.

2. Place the O-ring onto the centering ring.

3. Place the centering ring onto the calibrated leak.

4. Insert the calibrated leak into the cavity, orienting the leak so the value can be

read easily.

NOTE To ensure reliable testing, after servicing any part of the

vacuum system, th e 947/948/960 must be leak checked again.
Refer to “Leak Checking” on page 4-5 for guidelines.

5. Replace the top panel and connect mains power.

6. Turn the leak detector on and wait for the pumps to come up to speed.

7. Models 948/960 only: Once the system has pumped down, clean and fill the

Liquid Nitrogen Cold Trap using the procedure described in “Liquid Nitrogen Cold Trap
(Models 948/960 only)” on page 4-10.

Follow all warnings and cautions in the procedure.

8. Calibrate the 947/948/960 using the procedure described in “Re-calibrate the Internal

Calibrated Leak” on page 4-7.

9. Leak check the assembly before using the 947/948/960 for testing.

4-9

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.3 Liquid Nitrogen Cold Trap (Models 948/960 only)

The trap should be refilled with liquid nitrogen (LN2) as needed. A typical time frame for
refilling is every 14 hours, depending on usage. During normal usage of the 948/960
Platform leak detector, water vapor and other contaminants build up on the surface of the
nitrogen trap.

To clean the cold trap:

1. Shut down the machine completely.

2. After approximately 30 minutes, slowly open the vent valve on the top of the Liquid
Nitrogen trap to vent the trap.

3. Don protective gear, such as loose fitting gloves and eye or face shield, and remove the

cold trap.

WARNING Liquid nitrogen causes burns upon contact.

4. Clean the trap with soap and water only after it has warmed up to room temperature.

5. Rinse it well and dry it completely inside and out using a lint free cloth.

CAUTION The outside of the cold trap mu st be completely dry or ice will

form and can be dragged into sensitive equipment when the
leak detector is turned on.

6. Once the trap is clean, replace it in the 948/960, and close the vent valve on the top of
the Liquid Nitrogen trap.

7. To re-establish operation, carefully refill the trap with LN

, using the safety procedure

2

above, and follow normal startup procedures for Models 948/960.

4-10

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.4 Spectrometer Tube Overhaul

Spectrometer tube overhaul consists of removing, cleaning, and re-installing the
947/948/960 Spectrometer Tube Assembly.

WARNING Liquid nitrogen causes burns upon contact. Use appropriate

protective devices, including heavy loose gloves and eye or
face shields.

NOTE Models 948/960 only: Before servicing the Spectrometer Tube,

refer to “Liquid Nitrogen Cold Trap (Models 948/960 only)” on
page 4-10 for the proced ure to empty the Cold Trap, steps 1, 2,
and 3. Do not refill the Cold Trap until service is complete.

There are three basic sub-assemblies in the spectrometer tube:

❑ Ion Source
❑ Preamplifier
❑ Magnetic Poles

Table 4-3 lists the tools and parts required during spectrometer tube overhaul.

Table 4-3 Tools and Parts Required for Spectrometer Tube Overhaul

Tools

Slotted screwdriver Phillips screwdriver
5-64 Hex wrench Screw capturing screwdriver
Feeler gauge Socket wrench
Allen wrench

Part Part Number

Metal Seal L5873001
Ion Source 82850302
TC Gauge (TC1) F0472301
TC Gauge (TC2) F0472301
Spectrometer Tube Cleaning Kit 670029096
O-rings

4-11

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.4.1 Removal of the Spectrometer Tube and Preamplifier

Refer to Figure 4-2 for the removal of the 947/948/960 spectrometer tube.

WARNING Liquid nitrogen causes burns upon contact. Use appropriate

protective devices, including heavy loose gloves and eye or
face shields.

NOTE Models 948/960 only: Before servicing the Spectrometer Tube,

refer to “Liquid Nitrogen Cold Trap (Models 948/960 only)” on
page 4-10 for the proced ure to empty the Cold Trap, steps 1, 2,
and 3. Do not refill the Cold Trap until service is complete.

To remove the spectrometer tube:

1. Insert the plug in the test port and tighten the test port securely.

2. Shut down the leak detector via the Main switch/circuit breaker on the rear of the lower
cabinet.

3. Disconnect power from the leak detector.

4. Remove the lower front panel of the leak detector to allow access to the vacuum system.

5. Momentarily open the turbo vent screw

CAUTION Use powder-free butyl or polycarbonate gloves to prevent skin

oils from getting on vacuum surfaces.

➂, to bring the vacuum system to atmosphere.

4-12

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

6. Disconnect all four electrical connections to the spectrometer tube ➀.

NOTE To remove the locki ng connector shown in Figure 4-2,

both m etal tabs at the left of the connector must be pushed to
unlock the connector, then pull the connector to the right to
remove it.

➁

➀

➂

Figure 4-2 947/948/960 Spectrometer Tube Removal

7. Hold the spectrometer tube and loosen the wing nut holding the KF clamp

8. Remove the clamp that holds the spectrometer tube to the Service Block Assembly

(SBA).

9. Rock the tube to slowly break any residual vacuum.

10. Place the spectrometer tube and O-ring on a clean, non-magnetic bench for further

maintenance.

➁.

4-13

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.4.2 Disassembly of the Spectrometer Tube and Preamplifier

To disassemble the spectrometer tube:

1. Remove the four screws on the spectrometer tube (Figure 4-3), noting the placement of
the grounding strap

The grounding strap must go back on the same screw during reassembly.

CAUTION The preamplifier i s a static sensitive device. Wear a grounding

2. Loosen the four 5-64 Allen set screws on the edges of the magnet assembly that hold the
fixed and adjustable pole pieces in place.

➀.

device whil e the preamplifier is being handled.

3. Remove the pole pieces and the black plastic tuning knobs .

4. Separate the magnet assembly

5. Remove the four Phillips head screws that hold the flange cap
tube body.

6. Firmly but gently separate the flange cap from the ion source

7. Remove both the O-ring on the ion source, and the ion source.

8. Remove the ground slit plate
screw-holding screwdriver.

9. Remove the four slotted screws on each side of the spectrometer tube body and slip out
both deflection pole pieces

10. Remove the O-ring.

11. Remove the heater cartridge

12. Remove the five Phillips head screws that hold the preamplifier cover

13. Remove the preamplifier
following sequence:

❑ Remove the Phillips head screw at the base of the connector bracket.

12 11

➁ from the spectrometer tube body ➂.

➃ onto the spectrometer

➄.

➅ from the ion source cavity with a long, thin

➆. The deflection pole pieces are interchangeable.

➇ by pulling it free of its cavity.

➈ on.

➉, connector bracket, and collector housing assembly in the

4-14

❑ Remove the four socket head cap screws, sized 8-32, that mount the collector

housing to the spectrometer tube body, using a 9-64 short Allen wrench inserted
between the printed wiring board and the screw head.

❑ Remove the metal seal on the collector housing assembly.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

➃

➄

➂

➀

➁

➅

11

12

➇

➆

Figure 4-3 Spectrometer Tube Disassembly

➈

➉

WARNING Store the Ion Source in a cool, dry area in a tightly sealed

container . Wash hand s thoroughly after han dling the Ion Source
and especially before smoking or eating.

CAUTION Do not use methanol or other solvents on O-rings. To do so

causes dete rioration and red uce s t h eir ability to hold a vacuum.

Do not clean any aluminum parts with Alconox. Alconox is not
compatible with aluminum and will cause damage.

Use new O-rings wiped clean with a lint-free cloth. Do not
apply vacuum grease to O-rings that come in contact with the
spectrom eter tube.

4-15

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.4.3 Spectrometer Tube Cleaning

To clean the spectrometer tube:

™

1. Use the Scotch-Brite
remove heavy deposits from the ground slit plate, and spectrometer tube body.

2. Wipe all parts with VacuSolv wipes.

3. Allow parts to air dry thoroughly.

4.2.4.4 Rea ssembly of the Spectrometer Tube and Preamplifier

To reassemble the spectrometer tube:

Refer to Figure 4-4 for step 1 through step 5, to Figure 4-5 for step 6 through step 8, and
Figure 4-6 on page 4-18 for step 9 through step 13.

flexible abrasive pads from the spectrometer cleaning kit to

1. Place a new metal seal
crossed under one of the screw holes (Figure 4-4, View A).

2. Mount the collector housing assembly to the spectrometer tube body
socket head cap screws, sized 8-32.

3. Tighten all four screws in an opposing sequence until a 0.007" clearance is attained
between the collector housing assembly and the spectrometer tube body.

Use a feeler gauge to measure the clearance and another leak detector (if available) to
leak check to 1 x 10

4. The preamplifier
one unit can now be reattached to the spectrometer tube body by replacing the screw at
the base of the connector bracket.

5. Replace the preamplifier cover

A

➀ on the collector housing assembly ➁ with the ends of the seal

➂ with the four

−9

atm cc/sec.

➃, connector bracket, and collector housing assembly that came off as

➄ and the five Phillips head screws that hold it in place.

➄

A

➃

➁

➀

4-16

➂

Figure 4-4 Spectrometer Tube Reassembly

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

6. Put the heater cartridge ➀ back in its cavity (Figure 4-5).

➃

A

A

➂

➀

➁

Figure 4-5 Spectrometer Tube Reassembly (Ground Slit Plate)

7. With the new O-rings on each of the two deflection pole pieces

pieces into the spectrometer tube body
of the spectrometer tube, and note the positions of both the roll pin in the body and the
notch in the pole piece flange used for alignment.

8. When installing the ground slit plate

align the slit at 90° with the side wall of the spectrometer tube, and concentrically align
the circular hole in the plate with the smaller guide hole in the bottom of the ion source
cavity (Figure 4-5, View A).

9. Wipe the new O-ring

new ion source

❑ Place the locating pin ➂ approximately in the center of the guide hole.
❑ Ensure that pins 1 and 8 ➃ are parallel to the side wall of the spectrometer tube as

shown in Figure 4-6 on page 4-18, View A.

❑ Tighten the flange cap ➄ evenly and firmly with the four Phillips head screws.

CAUTION A short could result at power up if the alignment pin touches

➀ and mating surfaces with a clean, lint-free cloth and place the

➁ in its cavity (Figure 4-6 on page 4-18) as follows:

the sides of the alignment hole.

➂, tighten the four slotted screws on each side

➃, be sure that the snap prongs are facing up, then

➁, insert the pole

4-17

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

10. Fit the magnet assembly ➅ back onto the spectrometer tube body.

11. With the grounding strap
replace and tighten the four screws that fit into the magnet assembly.

12. Insert the pole pieces
are snug against the body, and tighten the 5-64 Allen set screws.

13. Leak check the assembly before reinstalling the spectrometer tube into the leak detector.

➆ attached to the same screw from which it was removed,

➇ and the black plastic knobs ➈ making sure that the pole pieces

➄

A

A

➁

➂

➂

➀

➃

➅

➆

Figure 4-6 Spectrometer Tube Reassembly (Magnet Assembly)

➇

➈

4-18

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.4.5 Reinstallation of the Spectrometer Tube

WARNING Liquid nitrogen causes burns upon contact. Use appropriate

protective devices, including heavy loose gloves and eye or
face shields.

NOTE Models 948/960 only: Before servicing the Spectrometer Tube,

refer to “Liquid Nitrogen Cold Trap (Models 948/960 only)” on
page 4-10 for the proced ure to empty the Cold Trap, steps 1, 2,
and 3. Do not refill the Cold Trap until service is complete.

To reinstall the spectrometer tube:

1. Place the cleaned, new, ungreased centering ring and O-ring on the vacuum flange of

the spectrometer tube.

2. Hold the spectrometer tube

as required.

3. Reconnect the four electrical connections that were disconnected from the spectrometer

tube.

Pay special attention when attaching the locking connector shown in Figure 4-7.

a. Press the tabs on the sides of the connector.

b. Push the connector onto its mating part.

c. Slide the tabs to lock the connector in place.

➀ in place and attach the KF clamp ➁ and tighten

➁

➀

Locking Connector

Figure 4-7 947/948/960 Spectrometer Tube Installation

4-19

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4. Models 948/960 only: Fill the Liquid Nitrogen Cold Trap using the procedure described
in “Liquid Nitrogen Cold Trap (Models 948/960 only)” on page 4-10, steps 5 and 6.

5. Reconnect power and start the leak detector and refer to the “Calibration and Sensitivity
Checks” on page 3-11.

6. Leak check before using for testing.

4.2.5 Air Filter

Check the air filter weekly for dust and dirt. Check more frequently if operating in a dirty
area. The removal of the front lower panel exposes the air filter, as shown in Figure 4-8.
When buildup of dirt, dust, or other contaminants is apparent, replace the filter with a
commercial filter (size 16" x 20" x 1").

➀

➁

Figure 4-8 Air Filter Replacement

➀ Front lower panel Removable front panel of the 947/948/960
➁ Air filter Commercial filter (16" x 20" x 1")

The air filter should be replaced at least every 12 months to ensure proper airflow through
the 947/948/960.

To replace the air filter:

1. Remove the front panel of the 947/948/960.

2. On the inside of the front panel, grasp the filter at the top.

4-20

3. Pull the filter up out of the holder.

4. Remove the filter element and discard it.

5. Place a new filter element into the housing.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.6 Spectrometer Tube Exchange

The spectrometer tube replaceable parts consist chiefly of the ion source, the preamplifier,
the magnetic poles, and the spectrometer tube as a complete assembly.

NOTE Because of the complexity and sensitivity of the preamplif ier,

Varian recommends replacing the entire spectrometer tub e if
the preamplifier must be replaced.

Rebuilt spectrometer tubes are available from Varian Vacuum
Technologies on an ex change basis. Contact Varian Vacuum
Technologies Customer Service at 1-800-8VARIAN for details.

Replacement of the ion source or preamplifier requires removal of the spectrometer tube.
Complete overhaul of the spectrometer tube includes complete disassembly of the
spectrometer tube including replacing the ion source and preamplifier. Both procedures
require that calibration, tuning and leak checking be performed prior to using the
947/948/960 for testing.

CAUTION Use powder- free butyl or polycar bona te g loves to preve n t skin

oils from getting on vacuum surfaces.

The preamplifier i s a static sensitive device. Wear a grounding
device whil e the preamplifier is being handled.

WARNING Store the Ion Source in a cool, dry area in a tightly sealed

container. When handling the Ion Source, wear powder-free
butyl or polycarbonate gloves. If you handle the Ion Source
with bare hands, wash them thoroughly and especially before
smoking or eating.

4.2.6.1 Removing and Replacing both the Spectrometer Tube Assembly and Preamplifier

Refer to “Disassembly of the Spectrometer Tube and Preamplifier” on page 4-14.

4.2.6.2 Rei nstalling the Spectrometer Tube

To perform this procedure:

1. Using a VacuSolv wipe, clean the SVBA flange and allow it to air dry completely.

2. Place the clean, new, ungreased centering ring and O-ring on the vacuum flange of the

spectrometer tube.

CAUTION Do not use grease or other substances on O-rings that come in

contact with t h e spectrometer tube.

Wipe all O-rings clean with a lint-free cloth before installation
to ensure that no foreign matter is present to impair the seal.

4-21

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

3. Hold the spectrometer tube against the centering ring, attach the NW25 clamp, and
tighten the clamp fully.

4. Reconnect the ion source connector, the preamplifier locking D-sub connector, the
Molex connector to the heater, and the suppressor.

a. When attaching the locking connector (Figure 4-9), press the tabs on the sides of the

connector

b. Push the connector onto its mating part.

c. Slide the tabs to lock the connector in place.

Ion Source Connector

Heater Power

Preamplifier Locking Connector

Suppressor

Figure 4-9 947/948/960 Spectrometer Tube Instal lation

NOTE To ensure reliable testing, after servicing any part of the

vacuum system, th e 947/948/960 must be leak checked again.
Refer to “Leak Checking” on page 4-5 for guidelines.

5. Replace the front panel and connect mains power.

6. Turn the leak detector on and wait for the system to be ready.

Allow the pumps to warm up if the detector has been off for some time.

7. Models 948/960 only: Once the system has pumped down, clean and fill the Liquid
Nitrogen Cold Trap using the procedure described in “Liquid Nitrogen Cold Trap
(Models 948/960 only)” on page 4-10.

4-22

Follow all warnings and cautions in the procedure.

8. Calibrate and tune the 947/948/960 using the procedure described in “Re-calibrate the
Internal Calibrated Leak” on page 4-7.

9. Leak check the assembly before using the 947/948/960 for testing.

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.7 TC1 and TC2 Gauge Replacement and Calibration

4.2.7.1 Replacement of the TC1 Gauge in the Main Valve Block Assembly

Figure 4-10 shows the valve block removed from the system.

NOTE It is not necessary to remove the valve block to replace the

TC1 thermocouple gauge.

To replace the TC1 gauge in the Main Valve Block Assembly (MVBA):

1. Press the VENT button on the front panel to vent the leak detector.

2. Disconnect the mains power supply and make sure all pumps are off.

3. Grasp the plug and remove the plug and the thermocouple gauge

block (Figure 4-10).

4. Disconnect the plug from the thermocouple gauge.

5. Remove the O-ring

➂ and backing ring ➁ from the thermocouple gauge (Figure 4-10).

➂

➁

➀

Figure 4-10 TC1 Gauge in the MVBA

➀ from the valve

4-23

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

6. Examine the O-ring for wear.

If necessary, use a new O-ring, otherwise clean the O-ring.

NOTE Before re-using O-rings or install ing new O-rings, wipe them

down with a lint-free cloth before installation to ensure that no
foreign matter is present to impair the seal. If applicable, apply
a small amount of Apiezon L grease and wipe the O-rings
"shiny" dry.

7. Wipe the O-rings clean with a lint-free cloth before installing to ensure that no foreign
matter is present to impair the seal.

8. Examine the backing ring.

If there are nicks or other signs of wear, replace it. If necessary, use a VacuSolv wipe to
remove any dirt or foreign matter from the backing ring, otherwise wipe it with a
lint-free cloth.

9. Place the backing ring
gauge and move them down toward the gauge as far as they will go.

10. Place the plug connector onto the thermocouple gauge.

The center post is keyed so it only goes on one way.

11. Insert the thermocouple gauge into the valve block making sure it is firmly seated into
the valve block.

12. Connect mains power.

13. Turn the leak detector on and wait for the system to be ready.

Allow the pumps to warm up if the detector has been off for some time.

14. Calibrate the thermocouple gauge using the procedure described in “Test Port Pressure
Gauge (TC1) Calibration” on page 4-29.

15. Calibrate using the procedure described in “Calibration Check” on page 4-5.

16. Leak check the assembly before using the 947/948/960 for testing.

➁ and then the O-ring ➂ onto the end of the new thermocouple

4-24

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.7.2 Replacement of the TC2 Gauge in the Service Block Assembly

WARNING Liquid nitrogen causes burns upon contact. Use appropriate

protective devices, including heavy loose gloves and eye or
face shields.

NOTE Models 948/960 only: Before servicing the Spectrometer Tube,

refer to “Liquid Nitrogen Cold Trap (Models 948/960 only)” on
page 4-10 for the procedure to clean the Cold Trap. Do not
refill the Cold Trap until service is complete.

Figure 4-11 shows the valve block removed from the system. To replace the TC2 gauge in
the Service Block Assembly (SBA):

1. Press the VENT button on the front panel to vent the leak detector.

2. Disconnect the mains power supply and make sure all pumps are off.

3. Models 948/960 only: Empty the LN

NOTE It is not necessary to remove the valve block to replace the

TC2 thermocouple gauge.

➁➂

➀

Cold Trap. Refer to the warnings listed above.

2

Figure 4-11 TC2 Gauge in the SBA

4. Loosen and remove the KF25 clamp

adapter

5. Remove the thermocouple gauge from the adapter.

6. Remove the O-ring from the centering ring.

➂, centering ring and O-ring.

➀ to remove the thermocouple gauge ➁,

4-25

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

7. Clean the centering ring and adapter with acetone. making sure all traces of pipe sealant
are removed from the threads of the adapter.

8. Examine the O-ring for wear.

If necessary, use a new O-ring, otherwise clean the O-ring by wiping it O-ring clean
with a lint-free cloth before installation to ensure that no foreign matter is present to
impair the seal.

NOTE If applicable, apply a small amount of Apiezon L grease and

wipe the O-rings "shiny" dry.

9. Place Loctite PST thread sealant onto the second and third threads of the new
thermocouple gauge.

10. Insert the thermocouple gauge into the adapter and hand tighten it fully.

11. Place the O-ring onto the centering ring and onto the flange of the SBA.

12. Place the adapter against the center ring.

13. Replace the KF25 clamp and tighten the wing nut fully.

14. Place the plug connector onto the thermocouple gauge.

The center post is keyed so it only goes on one way.

15. Models 948/960 only: Refill the Cold Trap using the procedure described in “Liquid
Nitrogen Cold Trap (Models 948/960 only)” on page 4-10.

16. Connect mains power.

17. Turn the leak detector on and wait for the system to be ready.

Allow the pumps to warm up if the detector has been off for some time.

18. Calibrate the thermocouple gauge using the procedure described in “System Pressure
Gauge (TC2) Calibration” on page 4-27.

19. Calibrate the leak using the procedure described in “Calibration Check” on page 4-5.

20. Leak check the assembly before using the 947/948/960 for testing.

4-26

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.7.3 Thermocouple Gauge Calibration Procedures

Use the Service Pendant to perform a calibration on either the system pressure
thermocouple (TC2) or the test port thermocouple gauge (TC1). Refer to Section A, “Service
Pendant Keypad Functions” on page A-1 for information about using the Service Pendant.

NOTE The calibration of the test port thermocouple (TC1) gauge is

factory set and requires the use of a reference TC and a PC.

4.2.7.4 Sys tem Pressure Gauge (TC2) Calibration

This procedure allows for calibration of the system pressure thermocouple gauge. Both the
Vacuum and Atmospheric Calibrations procedures must be performed in the order written.

4.2.7.4.1 Vacuum (Low Pressure) Calibration

To perform this procedure:

1. Verify that the leak detector is in the READY condition (the NOT READY LED is not

illuminated) and that the test port plug is in place.

2. If the system is not already in VENT mode, press the VENT button. Verify that the VENT

LED is illuminated.

3. Wait approximately five minutes for the vacuum system pressure to stabilize.

4. On the Service Pendant, press shift and the SY TC ZERO key.

❑ The Pendant screen confirms that the calibration was successful by displaying the

OK prompt.

❑ The Pendant screen displays FAILED before the OK prompt, indicating that the

calibration was not successful. This could be the result of a defective or
contaminated thermocouple gauge, or that the actual pressure was substantially
greater than 1 mTorr.

If the calibration was:

❑ Not successful, contact Varian Vacuum Technologies Customer Service at

1-800-8VARIAN.

❑ Successful, proceed to step 5.

5. Perform the next part of the calibration procedure (“Atmospheric Calibration”).

4-27

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.7.4.2 Atmospheric Calibration

Calibration of the system pressure thermocouple (TC2) gauge to atmosphere is only required
if the system TC2 gauge is replaced or if the calibration appears to be off.

NOTE Do not replace the side panels before performing this

To calibrate the system pressure thermocouple (TC2) gauge to atmosphere:

1. Once the system thermocouple (TC2) has been replaced and before powering up the
leak detector, turn off the ROUGH pump and DETECTOR switches.

2. Turn on the power switch located on the rear panel of the 947/948/960.

3. Wait for the system NOT READY LED to illuminate.

4. Open the turbo vent screw located on the side of the turbo pump housing.

5. On the Service Pendant, press shift and the SY TC ATM key.

procedure. You need access to the turbo pump.

❑ The Pendant screen confirms that the calibration was successful by displaying the

OK prompt.

❑ The Pendant screen displays FAILED before the OK prompt, indicating 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.

If the calibration was not successful, contact Varian Vacuum Technologies Customer
Service at 1-800-8VARIAN.

6. If the calibration was successful:

❑ Close the turbo vent screw.
❑ Replace any panels that were previously removed.

Calibration of the TC2 gauge is complete. You can now proceed with testing or place the
system in the mode you desire.

4-28

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.7.5 Test Port Pressure Gauge (TC1) Calibration

This procedure allows for calibration of the test port pressure thermocouple gauge (TC1).
Both the Vacuum and Atmospheric Calibrations procedures must be performed in the order
written. The vacuum calibration is factory set. Do not change this setting unless you have
the appropriate equipment.

NOTE The calibration of the test port thermocouple (TC1) gauge is

factory set and requires the use of a reference TC and a PC.

4.2.7.6 Vacuum (Low Pressure) Calibration

To perform this procedure:

1. Verify that the leak detector is in the READY condition (the NOT READY LED is not

illuminated) and that the test port plug is in place.

2. If the system is not already in VENT mode, press the VENT button and verify that the

VENT LED is illuminated.

3. Remove the plug from the test port and place a T-Manifold (1 1/8 inches [28 mm] OD)

into the test port.

4. Attach a Tuning Leak (Varian P/N K1608301) and a 531 Thermocouple Gauge Tube

(Varian P/N F0472301) as a reference TC to the T-manifold.

5. Connect the reference TC to an 801 Thermocouple Gauge Controller.

For 120 VAC, order Varian P/N F2739301; for 230 VAC, order Varian P/N F2739302.

6. Wait approximately five minutes for the vacuum system pressure to stabilize.

7. Adjust the Tuning Leak to 100 mTorr as indicated by the Varian 801 and verify that the

test port pressure on the test port pressure graph reads 1.0E-01 Torr.

8. Connect a PC to J1 inside the turret in place of the Service Pendant.

If using HyperTerminal (or equivalent), establish communication with the leak detector.

Refer to:

❑ “Communications Protocol” on page C-1 for the communication parameter setup
❑ “Inputs and Outputs” on page D-1
❑ “Service Serial Interface (J1)” on page D-1

4-29

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

9. Type XYZZY<CR>, then 100 INIT-TPTCZERO<CR>.

❑ The system should respond OK.
❑ The test port pressure on the test port pressure bar graph should read 1.0E-01 Torr.

A FAILED response on the PC is an indication that the calibration was not successful.
This could be the result of a defective or contaminated thermocouple gauge. If
necessary, replace the thermocouple gauge.

If after replacing the thermocouple gauge, calibration is still not successful, contact
Varian Vacuum Technologies Customer Service at 1-800-8VARIAN.

10. If the calibration was successful:

❑ Press the VENT button and remove the T-manifold, tuning leak, and reference TC

from the test port.

❑ Place test port plug into the test port and tighten the test port tightening nut fully.
❑ Remove the PC and connect the Service Pendant.
❑ Perform the next part of the calibration procedure (“Atmospheric Calibration”).

4.2.7.7 Atmospheric Calibration

To perform atmospheric calibration:

1. If the system is not already in VENT mode, press the VENT button and verify that the
VENT LED is illuminated.

2. Wait approximately ten seconds for the test port pressure to stabilize.

3. On the Service Pendant, press the TP TC ATM key.

❑ The Pendant screen confirms that the calibration was successful by displaying the

OK prompt.

❑ The Pendant screen displays FAILED before the OK prompt, indicating 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

If the calibration was:

❑ Not successful, contact Varian Vacuum Technologies Customer Service at

1-800-8VARIAN.

❑ Successful, calibration of the TC1 gauge is complete. You can now proceed with test-

ing or place the system in the mode you desire.

4-30

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.8 Rough Pump and Forepump Oil Level Check (Oil-sealed Mechanical Pumps)

Both the Rough pump and Forepump are equipped with an oil level sight glass that can be
viewed when the front lower panel cover is removed (Figure 4-12). Refer to your pump
manual for the proper oil level. If it is low, fill it to the proper level with Varian Vacuum
Technologies’ pump oil (part no. 695409005).

➀

Figure 4-12 Rough Pump and Forepump Oil Level Check

➀ Oil level view port

4-31

Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.8.1 Condition of Oil (Oil-sealed Mechanical Pumps)

Excess water in the oil of the Rough pump or the Forepump is indicated by a milky or frothy
appearance. Refer to your pump manual for instructions.

4.2.9 Cleaning the Test Port

The test port is located at the front center of Models 947/948/960. Thus, it is not necessary
to turn the leak detector off or disconnect it from mains power if this is the only procedure
being performed. If you are cleaning the test port in conjunction with other procedures that
require opening the leak detector, be sure to turn the leak detector off, disconnect it from
mains power, and for Models 948/960, remove and empty the cold trap.

4.2.9.1 Removing the Test Port

CAUTION If cleaning the test port in conjunction with performing other

service procedures, t urn t h e leak detect or off, d isconnect mains
power, and for Models 948/960, rem o ve and empty the cold
trap. Heed all warnings and cautions in the Preface of this
manual.

To remove the test port:

1. Turn the test port tightening nut counterclockwise to loosen it (Figure 4-13), then
remove the tightening nut and the test port plug.

CAUTION Be careful not to drop the test port plug when you remove the

test port tightening nut. It is deceptively heavy for its size.

Test Port Plug

Test Port Tightening Nut

Port Nut

Figure 4-13 The Test Port

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

2. Remove the test port compression ring and O-ring from the top of the test port

(Figure 4-14).

Figure 4-14 Remove the Test Port Compression Ring and O-ring

4.2.9.2 Examining and Cleaning the Test Port

To perform this procedure:

1. Remove the O-ring from the compression ring.

2. Examine the O-ring for wear. If necessary, use a new O-ring, otherwise clean the O-ring.

NOTE Varian Vacuum Technol ogies recommends replacing all

O-rings during routine maintenance or during any maintenance
procedure requiring that O-rings be removed.

3. Before re-using O-rings or installing new O-rings, wipe them down with a lint-free cloth

before installation to ensure that no foreign matter is present to impair the seal.

4. If applicable, apply a small amount of Apiezon L grease and wipe the O-rings “shiny”

dry.

CAUTION Remove O-rings carefully with your fingers. Do not use metal

tools for this task. This prevents scratching of any sealing
surfaces.

Do not use alcohol, methanol or other solvents on O-rings. To
do so causes deterioration and reduces their ability to hold a
vacuum.

5. Examine all parts of the test port, including inside the test port.

If necessary, use a VacuSolv wipe to remove any dirt or foreign matter and allow parts to
air dry.

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Models 947, 948 and 96 0 Leak Detect ors Oper ations a nd Servic e Ma nual

4.2.9.3 Replacing the Test Port

To replace the test port:

1. Place the O-ring into the groove of the compression ring.

2. Place the compression ring and O-ring onto the top of the test port (Figure 4-15).

Figure 4-15 Placing the O-ring and Compression Ring onto the Test Port

3. Place the test port tightening nut onto the test port and turn it clockwise until it is just
tight enough to stay in place.

4. Place the test port plug into the test port tightening nut, making sure it is completely
seated.

5. Tighten the test port tightening nut completely.

4.3 Spare Parts

Spare and exchange parts are available in the kits listed on the following pages. Contact
Varian Vacuum Technologies to order parts at 1-800-8VARIAN.

4.3.9.4 Ex change Ass emblies

NOTE Varian Vacuum Technologies will not accept any p art for ret urn

without both a properly completed Return Materials
Authorization (RMA) and a Health and Safety Data Sheet.
Contact Cust omer Service at 1-800-8VARIAN to obtain an RMA
and a Health and Safety Data Sheet.

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