Models 947, 948 and 960 Leak Detectors Operations and Service Manual
4-13
4.2.5.1 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 procedure 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
➂
, to bring the vacuum system to atmosphere.
CAUTION
Use powder-free butyl or polycarbonate gloves to prevent skin
oils from getting on vacuum surfaces.
