INFICON Cool Drawer Single Sensor - Manual (Page 43)

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Cool Drawer Single and Dual Sensors Operating Manual
4.1.2.2 Feedthrough Diagnostic Procedure
1 Remove the crystal drawer from the sensor head.
2 Disconnect the 15.2 cm (6 in.) BNC cable from the feedthrough.
3 Using a DMM, verify continuity from the BNC center pin on the feedthrough to
the center pin on the sensor head, refer to
section 4.1.1 on page 4-1 . A typical
value would be less than 0.2 ohms.
4 Verify isolation of the center pin on the feedthrough from the electrical ground
(feedthrough body). A typical value would be in excess of 10 megohms.
If the feedthrough, conduit tube, or BNC connector is defective, replace them,
reattach the BNC, and repeat this procedure starting at step 1, otherwise continue
at step 5.
5 Verify continuity from the center pin on the BNC connector of the feedthrough
to the center pin on the sensor head.
6 Verify isolation from the center pin to electrical ground (feedthrough body).
If the feedthrough system is found to be defective, look for defective contacts at the
feedthrough to conduit tube connection. Repair or replace the feedthrough as
necessary. Reattach the BNC and repeat this procedure starting at step 1.
Otherwise, continue at step 7.
7 Connect the BNC cable to the feedthrough and disconnect it from the Crystal
Interface Unit (or oscillator)
8 Verify continuity from the center pin of the sensor head to the un-terminated
end of the BNC cable.
9 Verify isolation from the center pin to electrical ground (feedthrough body).
If the feedthrough and BNC cable system is found to be defective, look for defective
contacts at the feedthrough to BNC cable connection. Repair or replace the
feedthrough as necessary, then reattach the BNC cable to the XIU and repeat this
procedure starting at step 2.