DH Instruments PPC2+, Manual

Page: 136 / 166

PPC2+™ Operation and Maintenance Manual
©2001 DH Instruments, Inc.
Page 128
5.2.1.3 ORDER OF OPERATIONS
If the PPC2+ has an absolute Lo RPT (AXXXX) and an absolute Hi RPT (AXXXX),
and the Hi RPT will be autozeroed by the Lo RPT (see Section 3.4.1), calibrate and
determine the ZNATERR of the Lo RPT Range3 prior to calibrating the Hi RPT.
This is necessary since the ZNATERR determinations for the Hi RPT ranges will be
made relative to the Lo RPT Range 3 (L3).
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
PPC2+ RPTs can be obtained in several ways.
When the PPC2+ 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/PM and ZOFFSET values can be used to calculate as received/as left values.
For example, backing out PA/PM on the as left data yields the transducer readings
with PA = 0 and PM = 1. Then applying the as received PA/PM and ZOFFSET values
to the readings calculates
as received readings (the readings that the transducer
would have made with the old PA/PM and ZOFFSET).
3^ S] \OMYWWOXNON ^RK^ K] \OMOS`ON€ `KV_O] YP :+:7 KXN D900=/> PY\ KL]YV_^O
<:>] SP K_^YdO\Y S] _]ON SX XY\WKV YZO\K^SYX LO \OMY\NON PY\ OKMR \KXQO Z\SY\ ^Y
\_XXSXQ^ROMKVSL\K^SYX>ROM_\\OX^:+:7MKXLO`SOaONLcZ\O]]SXQE=:/-3+6GKXN
]OVOM^SXQ &3X^O\XKV( &-KV( &@SOa( D900=/>] M_\\OX^ `KV_O MKX LO `SOaON Lc
Z\O]]SXQE=:/-3+6GKXN]OVOM^SXQ&+_^YD(&`SOa(
5.2.2 EQUIPMENT REQUIRED
1. Gas operated piston gauge (deadweight tester), with the following characteristics:
•
Accuracy of ± 0.0035 % of reading or better, if best PPC2+ accuracy is to
be obtained. A lower accuracy standard may be used but PPC2+ accuracy will be
degraded proportionally from published specifications.
•
Able to apply absolute pressures if the RPT is absolute (AXXXX) and will be
used in the absolute measure mode: Absolute pressures may be arrived at either
by operation relative to an evacuated bell jar or, for higher pressures, by addition of
atmospheric pressure measured by a high accuracy barometer. Absolute RPTs that
will not be used in absolute measure mode (as is often the case for higher pressure
RPTs) do not require the application of absolute pressure for calibration and may be
calibrated using a gauge pressure standard.