Models 947, 948 and 960 Leak Detectors Operations and Service Manual
vi
4.1.1.1 Leak Checking ............................................................................................... 4-5
4.1.1.2 General Suggestions for Leak Checking ........................................................ 4-6
4.2.2.1 Removing the Internal Calibrated Leak .......................................................... 4-7
4.2.2.2 Replacing the Internal Calibrated Leak .......................................................... 4-9
4.2.3 Liquid Nitrogen Cold Trap (Models 948/960 only) .................................................... 4-10
4.2.4
Liquid Nitrogen Cold Trap (Models 948/960 only)................................................ 4-11
4.2.5.1 Removal of the Spectrometer Tube and Preamplifier .................................. 4-13
4.2.5.2 Disassembly of the Spectrometer Tube and Preamplifier ............................ 4-15
4.2.5.3 Spectrometer Tube Cleaning ....................................................................... 4-17
4.2.5.4 Reassembly of the Spectrometer Tube and Preamplifier ............................ 4-17
4.2.5.5 Reinstallation of the Spectrometer Tube ...................................................... 4-20
4.2.6 Air Filter..................................................................................................................... 4-21
4.2.7 Spectrometer Tube Exchange .................................................................................. 4-22
4.2.8.1 Replacement of the TC1 Gauge in the Main Valve Block Assembly ........... 4-24
4.2.8.2 Replacement of the TC2 Gauge in the Service Block Assembly ................. 4-26
4.2.8.3 Thermocouple Gauge Calibration Procedures ............................................. 4-28
4.2.8.4 System Pressure Gauge (TC2) Calibration .................................................. 4-28
4.2.8.4.1 Vacuum (Low Pressure) Calibration .............................................. 4-28
4.2.8.4.2 Atmospheric Calibration ................................................................ 4-29
4.2.8.5 Test Port Pressure Gauge (TC1) Calibration ............................................... 4-30
4.2.8.6 Vacuum (Low Pressure) Calibration ............................................................ 4-30
4.2.8.7 Atmospheric Calibration ............................................................................... 4-31
4.2.9 Rough Pump and Forepump Oil Level Check (Oil-sealed Mechanical Pumps) ....... 4-32
4.2.10.1 Removing the Test Port ............................................................................. 4-33
4.2.10.2 Examining and Cleaning the Test Port ....................................................... 4-34
4.2.10.3 Replacing the Test Port .............................................................................. 4-35
4.3.10.4 Exchange Assemblies ................................................................................ 4-35
4.3.10.5 Replacement Parts ..................................................................................... 4-36
4.3.10.6 Replacement Parts ..................................................................................... 4-37