DH Instruments PPCH-G, Руководство по эксплуатации и обслуживанию

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3. OPERATION
Page 47 © 2007 DH Instruments, a Fluke Company
1. Final target pressure at which DUT indicated
cardinal value of the pressure point.
2.
<IN>
or
<OUT>
depending on whether DUT
was in or out of tolerance. DUT is <IN> if
cardinal point – PPCH-G pressure < DUT
tolerance * DUT span.
60.010 psi g IH
T60.012 IN 2/11
Press
[ENTER]
to accept this test point and proceed to the next test point or
[
←
]
to repeat the point.
Repeat set pressure, take reading and accept data at each point until all points in
the sequence have been accepted.
All QDUT tests end with a VENT command after the last point. To avoid the
VENT, press [ESC] after the last point.
After the last point in the sequence has
been completed, the display is:
AutoTest complete
1exit 2repeat 3data
Select
<1exit>
to go the MAIN run screen retaining the AutoRange that was
setup by QDUT.
Select
<2repeat>
to start the same test again at
<Prep & [ENT]>
.
Select
<3data>
to view the data collected in the QDUT AutoTest that was just
completed (see Section 3.4.5).
3.3.7 [HEAD]

PURPOSE
To cause a pressure fluid head correction to be added to or subtracted from the pressure
measured by the PPCH-G reference pressure transducer in order to predict the pressure at a
height other than the PPCH-G’s reference level.
 PRINCIPLE
PPCH-G is calibrated at the reference level marked on the instrument rear panel.
Frequently, when performing a calibration or test, the device or system under test is at a
different height than the PPCH-G’s
TEST
port. This difference in height, commonly called
head
, can cause a significant difference between the pressure measured by the PPCH-G at
its
TEST
port height and the pressure actually applied to the device under test which is at a
different height. In this case, it may be useful to make a head correction to the pressure
measured by the PPCH-G in order to predict the pressure actually applied at a DUT at a
different height.
PPCH-G can calculate
head
pressure over its working pressure range for a variety of gasses
as well as oil, water or a user defined liquid. The HEAD function allows the height difference
to be specified and causes the resulting head pressure to be added to the pressure measured
at the
TEST
port.
The
[HEAD]
function key is used to specify the height difference between the PPCH-G
reference level and another height. Entering a height of zero turns the function off.
The height units and the test fluid are specified by pressing
[SPECIAL]
,
<3Head>
(see Section 3.5.3).