PG7000™ OPERATION AND MAINTENANCE MANUAL
© 1998-2008 DH Instruments, a Fluke Company
Page 60
Repeat
Steps through for each desired differential pressure point.
Setting Zero Differential Pressure
See Figure 9 for a schematic of the Differential Mode Controller and its valves.
Zero differential pressure can be set by PG7000 or simply by setting the
Differential Mode Controller TEST BYPASS valve to the OPEN position which
connects the HIGH and LOW TEST ports together. The TEST BYPASS valve
OPEN position is a “true” zero. The zero differential pressure value set by
PG7000 has the same uncertainty as any other differential pressure point (see
Section 1.2.4.1). Comparing the DUT reading at zero set by TEST BYPASS in
the OPEN position and at zero set by PG7000 in differential mode like any other
differential pressure, can help quantify the quality of the current RPM
offset value. If the difference between the two zero readings is excessive, the
RPM offset value should be redetermined (see Section 3.9.4.1, Selecting
Differential Mode, Setting Static Pressure, Finding RPM Offset (
<1run>
)).
Also, consider correcting all the DUT readings by the difference in the zero
reading found in the two different conditions to correct for the defect in the
RPM offset.
Viewing Static Pressure and RPM Offset (<2view>)
To view the current RPM offset and the static pressure value at which the offset
was recorded, press
[MODE]
and select
<4dif>
,
<2view>
. This display is:
1.
RPM offset value that is currently active.
2.
PG7000 pressure at which RPM offset was
recorded.
Offset: -6.33 Pa
@99.8755 kPa a
Press
[ESCAPE]
to return to the
<Differential mode:>
menu.
Press
[ENTER]
to return to the previous run screen.
3.9.4.2
HIGH LINE DIFFERENTIAL MEASUREMENT MODE
(PG7102, PG7302 AND PG7202 ONLY)
PURPOSE
To define differential pressures at elevated line pressures up to 11 MPa (1 600 psi)
with PG7102 or 110 MPa (16 000 psi) with PG7202 in gas and up to 500 MPa
(72 500 psi) in oil.
High line differential (HL dif) mode operation is only supported by PG7102,
PG7202 and PG7302. HL dif mode operation requires the use of a two identical
PG7102, PG7202 or PG7302s in tandem. Both PG7000s must have nominally
identical piston-cylinders and one of the PG7000s must have a “tare” piston-
cylinder. The HL dif mode setup for pressure up to 110 MPa (1 600 psi) in gas
normally also includes an MPC1-D-1000 or MPC1-D-3000 manual pressure controller
and the PK-7100-MPCD-DIF Interconnections Kit P/N 401645. The HL dif mode setup
for pressure greater than 110 MPa uses GPC1 (gas), OPG1 or MPG1 (oil) and custom
interconnecting hardware.
