Models 947, 948 and 960 Leak Detectors Operations and Service Manual
4-30
4.2.8.3 Thermocouple Gauge Calibration Procedures
Use the Service Pendant to perform a calibration on either the system pressure
thermocouple (TC2) or the test port thermocouple gauge (TC1). Refer to Appendix A,
“Service Pendant Keypad Functions” for information about using the Service Pendant.
NOTE
The calibration of the test port thermocouple (TC1)
gauge is factory set and requires the use of a reference
TC and a PC.
4.2.8.4 System Pressure Gauge (TC2) Calibration
This procedure allows for calibration of the system pressure thermocouple gauge. Both the
Vacuum and Atmospheric Calibrations procedures must be performed in the order written.
4.2.8.4.1 Vacuum (Low Pressure) Calibration
To perform this procedure:
1. Verify that the leak detector is in the READY condition (the NOT READY LED is
not
illuminated) and that the test port plug is in place.
2. If the system is not already in VENT mode, press the
VENT
button. Verify that the VENT
LED is illuminated.
3. Wait approximately five minutes for the vacuum system pressure to stabilize.
4. On the Service Pendant, press shift and the
SY TC ZERO
key.
❑
The Pendant screen confirms that the calibration was successful by displaying the
OK
prompt.
❑
The Pendant screen displays
FAILED
before the
OK
prompt, indicating that the
calibration was not successful. This could be the result of a defective or
contaminated thermocouple gauge, or that the actual pressure was substantially
greater than 1 mTorr.
If the calibration was:
❑
Not successful, contact Varian Vacuum Technologies Customer Service at
1-800-8VARIAN.
❑
Successful, proceed to step 5.
5. Perform the next part of the calibration procedure (“Atmospheric Calibration”).