DH Instruments PPCH-G, Руководство по эксплуатации и обслуживанию

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3. OPERATION
Page 61 © 2007 DH Instruments, a Fluke Company
When the upper limit has been exceeded, the display of current pressure flashes and a
buzzer sounds at 2 second intervals. To return to normal operation, reduce pressure using
direct pressure control keys or an automated pressure command.
Upper limit values are specific to each range and measurement mode. Be careful not to
assume that the upper limit set in one measurement mode will apply to the other. For example, if
you set 50 MPa as the upper limit in gauge mode, the upper limit will not be 50 MPa in absolute
mode of the same range.
Upper limits are always specified and displayed in the currendt pressure unit of measure.
3.4.4.1 OVER PRESSURE FUNCTION
In addition to the UL function, PPCH-G has an over pressure function.
The over pressure function executes when a Q-RPT measures a pressure that is
104 % of its default span or a utility sensor measures a pressure that is 110 % of
its default span.
When PPCH-G is using an external Q-RPT in an RPM4, the PPCH-G utility
sensor or Hi Q-RPT acts as a watchdog. If the watchdog measures a pressure
greater than the maximum pressure of the active external Q-RPT, PPCH-G
executes the overpressure function.
The over pressure function causes all pressure control to be interrupted, changes
the active range to the default range of the Internal, Hi (IH) Q-RPT or utility sensor
and causes the measured pressure display to flash. The overpressure function
also logs the time and date of the overpressure condition in both user and factory
logs to assist in incident diagnosis (see Section 3.5.9).
To recover from an overpressure, correct the overpressure condition and cycle
PPCH-G power. Be sure to correct the condition that caused the overpressure
before cycling power.
RPM4 has its own, independent overpressure function. When a Q-RPT on an
RPM4 is active, both the PPCH-G and the RPM4 may execute overpressure routines in
response to an overpressure condition of the RPM4. See the RPM4 Operation and
Maintenance Manual for information on the RPM4 overpressure function.
3.4.5 <5AT
EST
>
 PURPOSE
To view the data files that are created when QDUT AutoTests are run (see Section 3.3.6.2).
 PRINCIPLE
PPCH-G supports QDUTAutoTests (see Section 3.3.6.2). When a QDUT AutoTest is run,
the PPCH-G pressure accepted by the operator, and <IN> or <OUT> condition, at each point
is logged. The logged pressure and an identifying header are stored in a data file. The data
file can be viewed immediately following the last point of the sequence by selecting
<3data>
.
In addition, the up to ten previous data files recorded can be viewed anytime using
[SETUP]
,
<5ATest>
.