DH Instruments PPCK PLUS, Operation And Maintenance Manual

Page: 126 / 150

PPCK+™ Operation and Maintenance Manual
©2001 DH Instruments, Inc .
Page 118
5.2.1.3 ORDER OF OPERATIONS
If the PPCK+ on-board barometer is to be used as the source of ZSTD for
autozeroing in absolute mode, the on-board barometer should be adjusted prior to
calibrating the PPCK+’s RPT.
The ZNATERR determination should be performed AFTER the RPT ranges have
been calibrated and new PA and PM values activated.
5.2.1.4 AS RECEIVED/AS LEFT DATA
Frequently, calibration reports 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
PPCK+ RPTs can be obtained in several ways.
When the PPCK+ 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, with knowledge of pressures applied, associated transducer readings,
PA and PM and ZOFFSET values can be used to calculate as received/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 ZOFFSET values to the readings calculates
as received readings (the
readings that the transducer would have made with the old PA and PM and
ZOFFSET).
It is recommended that "as received" values of PA and PM and ZOFFSET (for
absolute RPTs if autozero is used in normal operation) be recorded for each range
prior to running the calibration. The current PA and PM can be viewed by pressing
[SPECIAL] and selecting <4Internal>, <2Cal>, <1View>. ZOFFSET’s current value can
be viewed by pressing [SPECIAL] and selecting <1AutoZ>, <2view>.