Model 979 Series Helium Mass Spectrometer Leak Detector
3-10
DRAFT 9/15/03
3.1.5.1 System Pressure Gauge Calibration Procedure
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.g
3.1.5.1.1 Vacuum (Low Pressure) Calibration
1. Verify that the leak detector is in the SYSTEM READY condition on the Home Screen
(Figure 3-10) and that a test port cap is in place.
Figure 3-10
979 Touch Panel Home Screen
2. Place the service key (T009) into the key switch and set the key switch to the SERVICE
position (see Figure 1-8 on page 1-12).
3. If the system is not already in VENT mode, press the
VENT
button.
4. Press the
TEST
button and verify that the leak detector transfers to FINE TEST mode,
displaying 10
−
9
atm cc/sec or lower.
5. Wait approximately five minutes for the vacuum system pressure to stabilize.
6. Move to the GAUGE CALIBRATION screen (Figure 3-9 on page 3-9) if you are not
already there.
7. Touch the
SYSTEM TC ZERO
box.
❑
A CAL OK indication, to the right of the SYSTEM TC ZERO 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 substantially greater than 1 mTorr.
8. Touch
DONE
to leave the screen and return to the previous menu.
LEAK RATE: X.XXE-XX atm-cc/sec
T.P. PRESSURE: X.XE-XX Torr
SYS INFO
MENUS
REJECT# 2,4
SYSTEM READY
979
Summary of Contents for 979 Series
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