Varian 959D, Operation Manual

Page: 37 / 82

959D Leak Detector
2-9
1. Press VENT button to vent the test port to atmosphere.
2. Loosen the tightening nut and remove the test port plug in Figure 2-6 on page 2-6.
3. Connect a test object to the test port and tighten the tightening nut.
4. Press START .
When the test port pressure goes below 250 mTorr (shown as the green band on the
PRESSURE display), the TEST button illuminates indicating a measurement is in
progress.
If the test port pressure does not get down to 250 mTorr in three minutes, the system
assumes that there is a gross leak in the test object or the system is pumping down a very
large volume. The system goes into HOLD to allow more time for pumpdown. When the
pressure drops below 250 mTorr, the TEST reactivates.
The HOLD button illuminates for 30 seconds alternating with the START button every three
minutes if the test port pressure fails to drop below 250 mTorr.
NOTE
If the HI VAC OK or the FIL LED turn off, contact Varian
Vacuum Technologies Customer Service at 1-800-8VARIAN.
5. Observe the bar graph display to determine if the object passes or fails the leak test.
6. When the test is done:
❑
Press VENT .
❑
Loosen the test port tightening nut.
❑
Remove the test object.