Models 947, 948 and 960 Leak Detectors Operations and Service Manual
4-8
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
performing 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 power is removed. Refer to “Liquid
Nitrogen Cold 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.