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.