Model 979 Series Helium Mass Spectrometer Leak Detector
3-12
DRAFT 9/15/03
3.1.5.2.1 Vacuum (Low Pressure) Calibration
1. Verify that the leak detector is in the SYSTEM READY condition (Figure 3-10 on
page 3-10) and that a test port cap is in place.
2. Place the service key (T009) into the key switch and set the key switch to the SERVICE
position.
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 15 minutes for the vacuum system pressure to stabilize.
6. Touch the
TEST PORT TC ZERO
box.
❑
A CAL OK indicator, to the right of the TEST PORT TC ZERO box confirms that the
calibration was successful.
❑
A FAILED message indicates that the calibration was not successful.
A FAILED message can result from a defective or contaminated thermocouple gauge,
or the fact that the actual pressure was not at or near zero.
7. Touch the
DONE
button to leave the screen and return to the previous menu.
3.1.5.2.2 Atmospheric Calibration
1. Place the service key (T009) into the key switch and set the key switch to the SERVICE
position.
2. If the system is not already in VENT mode, press the
VENT
button.
3. Wait approximately ten seconds for the test port pressure to stabilize. Move to the
Gauge Calibration screen (Figure 3-9 on page 3-9).
4. Touch the
TEST PORT TC ATM
box.
❑
A CAL OK indication, to the right of the TEST PORT 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. Touch
DONE
to leave the screen and return to the previous menu.
Summary of Contents for 979 Series
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