5. MAINTENANCE, ADJUSTMENTS AND CALIBRATION
Page 149
© 2009 DH Instruments, a Fluke Company
Due to the relatively high compressibility of low pressure oil, the configuration routine does not produce
reliable results when run at a starting pressure under 1 MPa (150 psi). Therefore, the volume configuration
routine cannot be run under 1 MPa (150 psi). It is recommended that volume configuration be run at a
pressure greater than 7 MPa, if possible.
The test volume that PPCH has determined can be viewed using [SPECIAL], <1config>, <1volume>,
<2view>.
OPERATION
Poor control is usually caused by invalid control parameters, excessive leaks and restrictions in the test
system or other set up problems. These problems should be identified and eliminated before resorting to use
of the configuration function (see Section 6).
PPCH uses self diagnostics to determine when to run the volume configuration routine in dynamic
control mode. Therefore, it is not normally necessary to run the configuration routine separately.
Running the volume configuration routine may cause the set pressure to increase or decrease by up to
1.4 MPa (200 psi) from the starting point.
The volume configuration routine may be run at any pressure greater than 1 MPa (150 psi). Dynamic
pressure control mode must be active. The test system must be leak free (see Section 3.3.9 to leak check).
Wait at least five minutes after switching to dynamic control mode before running the volume
configuration.
Set a pressure greater than 1 MPa (150 psi) and preferably greater than 7 MPa (1 000 psi).
Wait five minutes after the set pressure is
Ready
(see Section 3.2.3).
To access the volume configuration function press
[SPECIAL]
,
<7internal>
,
<1config>
,
<1volume>
,
<1run>
. The display is:
Selecting
<1yes>
causes the volume determination routine to
run. While the routine is running,
<Running vol config…>
flashes on the bottom line of the PPCH display.
Run volume config?
1yes 2no
Completing the routine may take up to 2.5 minutes and cause the pressure to change by up to 1.4 MPa
(200 psi).
When the volume determination is complete the display is:
Vol estimate: 20 cc
Activate? 1yes 2no
Select
<1yes>
to activate the new volume determination. Select
<2no>
to retain the old volume
determination and return to the main run screen.
To view the estimate of test volume currently being used by PPCH, press
[SPECIAL]
,
<7internal>
,
<1config>
,
<1volume>
,
<2view>
.
