PPC3™ OPERATION AND MAINTENANCE MANUAL
© 2002-2007 DH Instruments, a Fluke Company Page 124
• Able to supply the recommended sequence of pressure points in the range to
be calibrated: See Section 5.2.4 for information on the recommended calibration point
sequence for various Q-RPT types and classes.
5.2.3 SET-UP AND PREPARATION
To set-up and prepare the PPC3 for calibration of an internal Q-RPT:
Set the PPC3 on a stable surface near the calibration standard at a height as close as
possible to the calibration standard’s reference height. Consider the connections that
may need to be made to the rear panel and access to the front panel display and keypad.
Connect a pressure supply greater than the maximum pressure to be applied during the
calibration to the PPC3 rear panel SUPPLY port (1/8 in. NPT F). (See Section 2.3.5.)
If the calibration will include pressures under atmospheric pressure, connect a vacuum
pump to the PPC3 rear panel EXHAUST port (1/4 in. NPT F). There will be a constant
bleed of gas through the EXHAUST port so the vacuum pump should be self-venting or
disconnected when OFF (see Section 2.3.6).
Connect the calibration standard output to the PPC3 rear panel TEST(+) port (1/8 in. NPT F).
DO NOT apply pressure to the TEST(+) port without having a pressure supply greater
than the applied pressure connected to the SUPPLY port. Do not cause sudden external
pressure changes. Damage to internal PPC3 components could result. Unless the piston
gauge used to calibrate the PPC3 has automated pressure control, it is highly
recommended that the PPC3 direct pressure control keys (see Section 3.1.3) be used to
slew and adjust pressure during the calibration. This will minimize the risk of accidental
overpressure of the PPC3 Q-RPTs.
5.2.4 RECOMMENDED CALIBRATION POINT SEQUENCE
Calibration adjustments to PPC3 Q-RPTs are made by adjusting calibration coefficients,
PA and PM (see Section 5.2.1.1). To adjust these coefficients to optimum values giving the
best results over the Q-RPTs complete operating range, specific calibration point sequences
are recommended. The recommended point sequence depends upon whether the Q-RPT
being calibrated is a Standard or Premium Class (see Section 1.2.2.1). The class of the
PPC3 Q-RPTs is indicated on the model number on the product label and on the rear panel
Q-RPT model (<s> for standard, <p> for premium, for example A7Ms or A7Mp).
Prior to running the calibration point sequence, the Q-RPT should be exercised by:
a) Setting full scale pressure.
b) Dwelling at full scale pressure for 5 minutes.
c) Returning to atmospheric pressure (vented). If the Q-RPT is a gas operated Axxx type,
use vacuum rather than atmospheric pressure.
d) Dwelling for twenty minutes.
A dwell time after setting the pressure of at least 60 seconds before taking data at each point
is recommended.
Section 5.2.4.1 gives calibration point sequences for Standard Class Q-RPTs and Section 5.2.4.2
gives calibration point sequences for Premium Q-RPTs.
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