DH Instruments PPC4, Руководство по эксплуатации и обслуживанию

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PPC4™ OPERATION AND MAINTENANCE MANUAL
© 2009 DH Instruments, a Fluke Company Page 12
CUSTOM CONTROL (see Section 3.2.13).
•
PPC4 pressure control may be adversely affected if the test connection
tubing is too restrictive. For optimum results, the inner diameter of the
connecting hose should be at least 1.75 mm (0.07 in.).
2.3.7.1 Installing a Self Purging Liquid Trap (SPLT)
The SPLT (optional) is intended to collect and exhaust liquid or other
contaminants that may be present in the device or system under test so that they
do not return to contaminate the PPC4.
The SPLT is installed in the TEST(+) connection line at a low point between
PPC4 and the device or system under test. If the PPC4 system includes external
Q-RPTs in an RPM4, the RPM4 should be connected on the PPC4 side of the SPLT.
See the SPLT Operation and Maintenance manual for more complete instructions
on SPLT installation.
2.3.7.2 Installing a Dual Volume Unit (DVU), G15K and
BG15K Q-RPTS
To achieve in tolerance pressure control with the very low range of the G15K and
BG15K Q-RPTs, a PK-PPC-BG-DVU dual volume unit should be installed in-line
on the
TEST(+) and TEST(-) ports. The DVU includes two thermally isolated
volumes installed in the test line to improve control stability.
See the PK-PPC-BG-DVU instruction sheet for additional information on its
installation.
2.3.8 The ATM Port
The PPC4 ATM port is the system vent to atmosphere point used to set zero gauge pressure as well
as to obtain Q-RPT measurements of atmospheric pressure. Though a pressure hose can be
connected to the
ATM port to direct the vented gas flow, a completely unobstructed
connection to atmosphere must be maintained for PPC4 reference pressure measurements
to operate normally.
The PPC4 ATM port fitting is 10-32 UNF .

Caution
NEVER plug, obstruct or connect a supply pressure to the PPC4 ATM port.
This may adversely affect GAUGE mode operation and AutoZeroing
functions.
2.3.9 Check/Set Security Level
PPC4 has a security system based on user levels. By default, the security system is set to
“low”, which includes certain access restrictions, and there is no password required to change
the security level. See Section 3.2.26.4 for information on the security level system. As part
of the PPC4 startup, determine the security level that is appropriate for the PPC4 and set a
password if desired.

Caution
PPC4 is delivered with the security level set to “low” to avoid inadvertent
altering of critical internal settings but with access to changing security
levels unrestricted. It is recommended that the low security level be
maintained at all times and password protection be implemented if control
over setting of security levels is desired.