DH Instruments ADCS-601, Operation And Maintenance Manual

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ADCS-601™ OPERATION AND MAINTENANCE MANUAL
© 2005 DH Instruments, Inc. Page 154
Figure 65. ADCS Tools PG7601 Piston-Cylinder Calibration Form
7.3.5 PG7601, CALIBRATION OF REFERENCE VACUUM CDG
7.3.5.1 OVERVIEW
The PG7601 Platform is equipped with a capacitance diaphragm gauge (CDG),
power supply and read-out that are used to measure the reference vacuum
under the PG7601’s bell jar in absolute easurement mode. The capacitance
diaphragm gauge should be regularly zeroed (see Section 7.2.6). It should also
be calibrated.
To be calibrated, the CDG and its power supply and readout must be removed
from the ADCS-601 system. See Section 7.3.5.2 for instructions on removing
the PG7601 CDG assembly and readout.
The CDG and its power supply/readout are completely autonomous elements
whose calibration is independent of ADCS-601. The units should return from
calibration adjusted to operate within manufacuturer’s specifications. No
settings in ADCS-601 are required when the CDG and supply/readout are
reinstalled.
7.3.5.2 REMOVING THE CDG ASSEMBLY
The PG7601 CDG includes a vacuum isolation valve to maintain it under
vacuum. When connecting or disconnecting the PG7601 CDG from the AMH-
38 vacuum chamber, never break the fitting between the valve and the CDG.
Always make and break on the other side of the valve so that vacuum is
maintained on the CDG at all times.