DH Instruments PPCK PLUS, Руководство по эксплуатации и обслуживанию

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PPCK+™ Operation and Maintenance Manual
©2001 DH Instruments, Inc .
Page 124
5.3 ADJUSTMENT OF ON-BOARD BAROMETER
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PURPOSE
To adjust the output of the on-board barometer (see Section 1.2.2.2).
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PRINCIPLE
The on-board barometer output can be adjusted using PA and PM values in the same manner as
the reference pressure transducer (see Section 5.2.1).
The on-board barometer is a low accuracy sensor used only for measuring changes in atmospheric
pressure over short periods of time (see Section 3.4.1). It needs a traceable calibration only if it
is to be used as the source of ZSTD for autozeroing the PPCK+ RPT in absolute measurement
mode (see Section 3.4.1).
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OPERATION
To edit the values of PA and PM for the barometer, press [SPECIAL] and select <4Internal> ,
<2cal> , <2barometer> . Pressing [ENTER] steps through displays of the calibration date
[YYYYMMDD] and PA and PM. In edit mode, the values can be edited. Pressing [ENTER] after
the last screen activates the edited values.
To view the current atmospheric pressure measurement made by the barometer board, press
[SPECIAL] and select <4Internal>, <7Atm>.
5.4 DRAIN PURGE
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PURPOSE
To purge any liquids that may have collected in the PPCK+ thermal pressure c o n t r o l
unit (TPCU) volume.
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PRINCIPLE
PPCK+ is designed to precisely measure, set and control gas pressures. Liquid contamination of
the PPCK+ internal pneumatic control module and/or reference pressure transducer can cause
poor pressure control and interfere with pressure measurement. Liquid contaminants that may
be present in test devices or systems that are connected to the PPK+ TEST port are likely to
make their way back to PPCK+’s internal pneumatic system as the test device or system is
pressurized and depressurized by PPCK+. To every extent possible, only clean hoses and
connections should be used in connecting PPCK+ to test devices or systems and those devices
and systems should be free of contaminants.