DH Instruments ADCS-601, Operation And Maintenance Manual

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7. MAINTENANCE OF TRACEABILITY AND RECALIBRATION
Page 141 © 2005 DH Instruments, Inc.
7.2.3.3 VIEWING FPG VALIDATION DATA
FPG Validation test results can be viewed in a pop-up screen at the end of the
test (see Section 7.2.3.2, Figure 60).
The results of FPG Validation tests are also logged in *.dat files like other
automated tests. See Section 4.4.3.3 for additional information on *.dat files.
The Root Data directory defined in [Tools] , [Test Options] specifies the file
location. The default subdirectories are :
\Data\FPGValidation
\Data\FPG-PPC
\Data\PG-PPC
7.2.4 FPG8601, CHECK ON-BOARD P, T, H MEASUREMENTS
Check that the FPG8601 on-board pressure, temperature and humidity measurements are
within their acceptable range. Table 22 lists the measurements and their limits:
The measurement values can be viewed on the ADCS Tools FPG Run Screen (see Section
4.3.6.2).
If the temperature value is out of range, the temperature control in the environment in which
the ADCS-601 is inadequate.
If the lubrication gas pressure is outside of limits, check the adjustment of the FPG
Lubrication regulator on the Gas Supply Panel in the Control Cabinet (see Section 6.13).
If the lubrication gas relative humidity is out of limits low, check the FPG8601 bubbler for
adequate water level (see Section 6.2).
Table 22. FPG8601 P, T, H limits
MEASUREMENT VALUE AND LIMITS
Lubrication gas pressure (gauge mode) 140 kPa abs ± 8
Lubrication gas pressure (absolute mode) 40 kPa abs ± 8
Lubrication gas relative humidity 40 to 70 %RH
Mounting post temperature 19 to 27 ºC
7.2.5 FPG8601, VALIDATE LOAD CELL LINEARITY
7.2.5.1 OVERVIEW
The FPG8601 uses a precision load cell to measure the force resulting from the
pressure across its piston-cylinder. In normal operation, the only adjustments to
the load cell that are necessary to maintain in tolerance measurements is to zero
and span it which can be performed automatically by the ADCS-601 system (see
Sections 2.2.2, 7.2.2).
The linearity of the load cell is set at the factory and cannot be adjusted by the
user. In day to day operation load cell linearity is verified by the combination of
the zeroing process and the FPG Validation routine (see Section 7.2.3).
If the linearity problem with the load cell is suspected, it can be verified by
loading masses directly onto the load cell throughout its operating range. This
allows the load cell to be verified independently of the behavior of the FPG8601
piston-cylinder and without requiring a precision pressure reference.
The load cell linearity verification is performed using the FPG8601 Calibration
and Linearization Bracket (CLB) and mass set. The mass set consists of
masses of 3 x 500 g, 2 x 200 g, 1 x 100 g.