Model 979 Series Helium Mass Spectrometer Leak Detector
DRAFT 9/15/03
3-11
3.1.5.1.2 Atmospheric Calibration
Calibration of the system pressure thermocouple (TC) gauge to atmosphere is only required
if the system TC gauge tube is replaced or if calibration appears to be off.
1. Upon replacement of the system TC, unplug the mechanical pump(s) from the back of
the 979 before powering up the leak detector.
2. Turn the power ON to the 979 and go to the Gauge Calibration touch screen menu.
3. Place the service key (T009) into the key switch and set the key switch to the SERVICE
position.
4. Touch the
SYSTEM TC ATM
box.
❑
A CAL OK indication to the right of the SYSTEM TC ATM box confirms that the
calibration was successful.
❑
A FAILED message indicates that the calibration was not successful. This could be
the result of a defective or contaminated thermocouple gauge, or that the actual
pressure was not at or near atmosphere.
5. Power down the leak detector.
6. Plug the mechanical pumps into the appropriate receptacles and turn the power
back on.
3.1.5.2 Test Port Pressure Gauge Calibration Procedure
This procedure allows for calibration of the test port pressure thermocouple gauge. Both the
Vacuum and Atmospheric Calibrations procedures must be performed in the order written.
The vacuum calibration is factory set. Do not change this setting unless you have the appro-
priate equipment.
NOTE
The calibration of the test port thermocouple (TC) gauge is
factory set and requires the use of a reference TC and a PC.
Summary of Contents for 979 Series
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