Agilent Technologies 947 Betriebs- Und Servicehandbuch Seite 8

Models 947, 948 and 960 Leak Detectors Operations and Service Manual
B.5.2 Dry System ..............................................................................................................B-26
B.5.2.1 Removing the Dry System 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 Removing 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 Replacing the Isolation Valve ........................................................B-28
B.5.2.2.5 Replacing the Exhaust Fitting .......................................................B-29
B.5.2.2.6 Completing Mounting the Pump to the Cabinet Floor ...................B-29
Appendix C. Communications Protocol .....................................................................................C-1
C.1 Protocol (RS-232)................................................................................................................C-1
Appendix D. Inputs and Outputs .................................................................................................D-1
D.1 Service Serial Interface (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 Interface (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
Technische Daten für 947/948 ......................................................................................................... 4
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 of Leak Detection ................................................................................................. G-1
G.3 Terminology ....................................................................................................................... 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-4
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
Index ................................................................................................................................................ I-1
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