2. INSTALLATION
Page 15
© 2007 DH Instruments, a Fluke Company
It is normal for PPCH-G to indicate a value other than zero for up to thirty seconds
when first entering
gauge
mode. After ten to thirty seconds, the VENT LED
should flash and zero should be indicated. If this does not occur, check that the
AUTOZERO function is ON (see Section 3.5.1). If AUTOZERO is ON and the
displayed pressure will not zero when vented in gauge or bi-directional gauge
measurement mode, PPCH-G may need repair.
If a non-zero head correction value is active, PPCH-G may not indicate zero when
vented in gauge mode. Use [HEAD] to set the head height to zero (see Section 3.3.7).
Using the
[RANGE]
function key to change ranges, observe that zero is
indicated for each Q-RPT within 10 to 30 seconds.
2.4.5
LEAK CHECK
PPCH-G will control pressure properly if the system connected to the
TEST
port has excessive
leaks. See Section 3.3.9 for information on the PPCH-G leak test function.
For PPCH-G to operate properly, the leak rate in the test system after stabilization should not
exceed 0.002% of reading/second. In DYNAMIC CONTROL mode, to handle higher test
system leak rates, increase the hold limit using CUSTOM CONTROL (see Section 3.4.6.1) or
use HI VOLUME DYNAMIC CONTROL (see Section 3.2.2.2).
Use [LEAK CHECK] to perform a leak check of the PPCH-G and the system to which it is
connected.
Verify the maximum pressure rating of the system connected to the PPCH-G TEST port
before setting a leak check pressure. Do not set a pressure greater than the pressure rating of
the system or instruments connected to the PPCH-G TEST port.
2.4.6
CHECK PRESSURE CONTROL OPERATION
Select a pressure range using
[RANGE]
(see Section 3.3.1).
Press
[SETUP]
,
<6control>
,
<2mode>
,
<1dynamic>, <1standard>)
(see Section 3.4.6). If
PCH was not already set to dynamic control mode, wait 5 minutes for the thermal pressure
controller to stabilize.
Press
[ENT/SET P]
. Key in a target pressure within the active range and press
[ENT]
again
(see Section 3.3.10).
Verify the maximum pressure rating of the system connected to the PPCH-G TEST port
before entering a target pressure. Do not enter a target pressure greater than the pressure
rating of the system or instruments connected to the PPCH-G TEST port.
PPCH-G should set the target pressure and indicate
Ready
(see Section 3.2.3) continuously
in 90 to 150 seconds. If it does not, see Section 6 to troubleshoot.
