Edwards APG200

6. Maintenance
6.1 Atmospher
e and vacuum adjustment
Every gauge is adjusted before shipment however thermal conducvity gauges can dri
with me or as contaminaon builds up on the lament. You can adjust the atmosphere
and vacuum sengs of the gauge to eliminate the eects of such dri. The frequency of
adjustment will vary depending on the level and nature of the contaminaon associated
with the process.
Note:
The gauge can de
termine whether to perform atmosphere or vacuum adjustment based
on the measured pressure. If the adjustment is performed at an inappropriate pressure,
the calibraon error is triggered. Refer to Fault nding on page 39.
6.1.1 Atmosphere adjustment
1. Supply power to the gauge, make sure that the LED indicator is green and allow the
gauge to warm up at atmospheric pressure in nitrogen or air for at least
10 minutes.
2. Refer to Appendix - Mul-funcon buon operaon on page
45, select the
atmosphere or vacuum adjustment funcon using the mul-funcon push buon.
3. When the atmosphere or vacuum adjustment funcon is selected (LED indicator is
permanently indicated cyan), conrm the selecon by momentarily pressing and
releasing the mul-funcon push-buon.
4. The LED indicator will ash cyan to indicate the operaon is being performed.
5. Aer 3 seconds, the LED indicator stops ashing and the atmosphere adjustment
parameters are stored in the gauge.
6.1.2 Vacuum adjustment
1. Reduce the system pressure to 1 x 10
-5
mbar (or less).
2. Operate the gauge for minimum 10 minutes.
3. Refer to Appendix - Mul-funcon buon operaon on page
45, select the
“atmosphere/vacuum adjustment” funcon using the mul-funcon push buon.
4. When the atmosphere/vacuum adjustment funcon is selected (LED indicator is
permanently indicated cyan), conrm the selecon by momentarily pressing and
releasing the mul-funcon push buon.
5. The LED indicator will ash cyan to indicate the operaon is being performed.
6. Aer 3 seconds, the LED indicator stops ashing and the v
acuum adjustment
parameters are stored in the gauge.
6.1.3 Remote adjustment - APG200 with transistor setpoint [blank] opon
The gauge with transistor setpoint has a remote adjustment feature. You can perform
atmosphere adjustment and vacuum adjustment through the appropriate pin on the
electrical connector.
07/2021 - ©Edwards Limited
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D1G0000880_A - Maintenance