DH Instruments PPC4, Руководство по эксплуатации и обслуживанию

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PPC4™ OPERATION AND MAINTENANCE MANUAL
© 2009 DH Instruments, a Fluke Company Page 34

PRINCIPLE
PPC4 is designed to precisely set, control and measure gas pressure. Liquid contamination
of the PPC4 internal pressure control module and/or the Q-RPT module can cause poor
pressure control and interfere with pressure measurement. Liquid contaminants that may be
present in test devices or systems that are connected to the PPC4
TEST(+) port are likely to
make their way back to PPC4’s internal pneumatic system as the test device or system is
pressurized and depressurized by PPC4. To every extent possible, only clean hoses and
tubing should be used to connect PPC4 to test devices or systems and those devices and
systems should be free of liquid contaminants. However, in the event that PPC4 must used to
test devices or systems that may contain small amounts of liquid contaminants, a Self Purging
Liquid Trap (SPLT) accessory supported by the Purge function is available.
Execution of the PURGE function is automated and proceeds as follows:
If current pressure is greater than 700 kPa (100 psi) gauge, pressure is controlled down
to less than 700 kPa (100 psi) gauge.
Pressure control stops and a 5 second wait occurs.
SPLT exhaust valve is opened.
PPC4 waits until pressure is less than 20 kPa (3 psi) gauge or 110 kPa (16 psi) absolute.
PPC4 internal vent valve is opened with the SPLT exhaust valve left open.
Note
•
The Purge function makes use of the PPC4 valve driver option. Valve
driver number 8 is used to actuate the SPLT exhaust valve. When
making use of valve drivers, note that if the Purge function is enabled,
valve driver number 8 will be actuated independently of valve driver
commands. See Section 3.2.23.
•
For the Purge function to execute an optional Self Purging Liquid Trap
(SPLT) must be installed in the test line (see Section 2.3.7.1) and the
function must have been enabled. To enable with the Basic Interface:
<Spec>, <Internal>, <Purge> from the Main Menu (see Section 4.5.7.4).
To enable with the Advanced Interface:
[Settings], <Internal>, Purge
(see Section 5.7.12.3).
•

at any time during execution of the purge routine causes the purge
function to abort and returns to the Main Run Screen.
•
The internal volume of the SPLT is about 20 cc. The SPLT will not
operate effectively if the volume of liquid contaminants collected is
greater than about 10 cc. The SPLT is designed to protect the PPC4
only against residual liquid contamination. Even if an SPLT is being
used, precautions should be taken to reduce potential liquid
contamination from the device or system under test as much as
possible before making the connection to the PPC4 TEST(+) port.
•
Do not plug the SPLT exhaust valve. The purge routine can not be
completed with the SPLT exhaust valve plugged and the SPLT’s
protective function will not be effective.
•
If the SPLT is electrically connected to the PPC4, its exhaust valve will
always be open when the PPC4 vent valve is open. If desired, it may
be closed manually using the Driver function (see Section 5.7.4 in the
Advanced Interface or Section 4.4.6 in the Basic Interface).

OPERATION
For Basic Interface operation, see Section 4.5.17.
For Advanced Interface operation, see Section 5.7.3.1.