DH Instruments PPC2+, Manual

Page: 55 / 166

PPC2+™ Operation and Maintenance Manual
Page 47
©2001 DH Instruments, Inc.
3.2.8.5 TYPICAL USE OF THE LEAK CHECK/PURGE FUNCTION
The most common use of the LEAK CHECK/PURGE function is at the beginning of a
test just after the device or system under test has been connected to the PPC2+
TEST port. Generally, the purge process should be completed before leak checking
is performed. This may not be the case when the PPC2+ will be used to apply only
ascending pressures.
To purge:
•
Press the [LEAK CHECK] function key.
•
Use the direct manual pressure control keys to set the desired purge pressure
(generally full scale of the device or system under test or 150 psi (1 MPa),
whichever is lower).
•
Wait for pressure to stabilize.
•
Press the [VENT] key to cause the purge function to execute. Wait for purge
function to execute completely. Observe whether any liquid contaminants
exhaust from the SPLT exhaust valve.
•
Repeat from all steps until no noticeable amount of liquid contamination is
observed exhausting from the SPLT exhaust valve.
To leak check:
•
Press the [LEAK CHECK] function key.
•
Use the direct manual pressure control keys to set the desired leak check
pressure (generally full scale of the device or system under test).
•
Wait for pressure to stabilize.
•
Observe the leak rates displayed in the leak check screen to determine if the leak
rate is within acceptable limits. If leak rate is not acceptable, identify the source of
the leak, vent system and eliminate the leak if possible.
•
Repeat from all steps until leak rate observed in is acceptable.
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