DH Instruments PPCH, Руководство по эксплуатации и обслуживанию

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PPCH™ OPERATION AND MAINTENANCE MANUAL
© 2009 DH Instruments, a Fluke Company Page 138
As editing PA and PM values will change Q-RPT calibration, they should only be
edited by qualified personnel as part of the calibration process. Caution should be
taken to avoid accidental editing and a security system is available to prevent access
(see Section 3.5.5.5). Incorrect editing of PA and PM values can cause out of
tolerance measurements.
A new PPCH is delivered with PA and PM values set to zero and 1 for all ranges.
This does not mean that the PPCH has not been calibrated. In the original factory
calibration, privileged factory coefficients are used for calibration with the user PA
and PM set to zero and 1.
5.3.1.2 AS RECEIVED AND AS LEFT DATA
Frequently, calibration procedures require that as received and as left data be
reported. The necessary information to report as received and as left data on the
calibration of PPCH Q-RPTs can be obtained in several ways.
When the PPCH CalTool calibration assistance software is used, as received
data is displayed while running the calibration and is automatically recorded and
provided if desired. As left data is also calculated and presented.
At any time, a) reference pressures applied, b) associated Q-RPT readings,
c) PA, PM and P
offset
values can be used to calculate as received and as left values.
For example, backing out PA and PM on the as left data yields the transducer
readings with PA = 0 and PM = 1. Then applying the as received PA and PM
and P
offset
values to the readings calculates as received readings (the readings
that the transducer would have made with the old PA, PM and P
offset
).
A new PPCH is delivered with PA and PM values set to zero and 1 for all ranges.
This does not mean that the PPCH has not been calibrated. In the original factory
calibration, privileged factory coefficients are used for calibration with the user PA
and PM set to zero and 1.
It is recommended that “as received” values of PA, PM and P
offset
(P
offset
for
absolute mode calibrations if AutoZero is used in normal operation) be recorded for
each range prior to running the calibration. The current PA and PM and absolute
mode P
offset
an be viewed by pressing [SPECIAL], <8cal>, <1view>.
A new PPCH is delivered with PA and PM values set to zero and 1 for all ranges.
This does not mean that the PPCH has not been calibrated. In the original factory
calibration, privileged factory coefficients are used for calibration with the user PA
and PM set to zero and 1.