Inficon SQM-160, Operating Manual

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SQM-160 Operating Manual
6.4.1 Diagnostic Procedures
The following diagnostic procedures employ the Crystal Sensor Emulator to
analyze a constant Crystal Fail message. The symptom is a Crystal Fail message
that is displayed by the SQM-160 even after the monitor crystal has been replaced
with a new good monitor crystal.
6.4.1.1 Measurement System Diagnostic Procedure
1
Refer to Figure 6-8 on page 6-15 . Remove the six-inch BNC cable from the
feedthrough at point A.
2
Connect the Crystal Sensor Emulator to the 6 inch BNC cable at Point A.
 If the Crystal Fail message disappears after approximately five seconds,
the measurement system is working properly. Re-install the six-inch BNC
cable to the feedthrough. Go to
section 6.4.1.2 .
 If the Crystal Fail message remains, continue at step 3.
3
Disconnect the six-inch BNC cable from the Oscillator and from the Emulator.
4
Visually inspect the six-inch BNC cable to verify that the center pins are seated
properly.
5
Use an Ohm meter to verify the electrical connections on the six-inch BNC
cable.
 There must be continuity (<0.2 ohms, after accounting for resistance of
ohmeter leads) between the center pins.

There must be isolation (>10 megohms) between the center pins and the
connector shield.
 There must be continuity between the connector shields.
Replace the six-inch BNC cable if it is found to be defective and repeat Step 2
of this procedure.
6
If the six-inch BNC cable is not defective, re-connect the six-inch cable to the
oscillator and to the Crystal Sensor Emulator. If the Crystal Fail message
remains, contact INFICON.