DH Instruments PPCH-G, Руководство по эксплуатации и обслуживанию

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3. OPERATION
Page 55 © 2007 DH Instruments, a Fluke Company
If PPCH-G is unable to control pressure or appears to control pressure poorly,
see Section 6 to troubleshoot.
See Section 3.4.6 for information on customizing pressure control
parameters.
3.3.10.4 RAMP CONTROL MODE, [ENT/SET P]
If the PPCH-G is not set for ramp control, use
SPECIAL, <6control>
,
<2mode>
to select ramp control mode.
Use ramp control with caution. An ascending ramp will not stop increasing
pressure until stopped by a new pressure command, aborting control or reaching the
active range upper limit pressure (see Section 3.4.4).
For best results, wait 5 minutes with the PPCH-G vented before controlling
pressure when changing to or from standard dynamic control mode. This is to allow
time for the PPCH-G thermal pressure control unit to respond and stabilize.
Press
[ENT/SET P]
from the MAIN RUN screen. The display is:
1. Standard MAIN RUN screen first line showing
measured pressure and active Q-RPT.
2. Edit field for the target ramp rate in current
pressure unit of measure per second.
20.007 MPa g HI
Target rate:0.1000/s
Edit the target ramp value as desired. Enter a negative value for a descending rate.
A rate entry of 0 is not accepted.
Press
[ENT/SET P]
to start pressure control to the target ramp rate and return to
the MAIN RUN screen. The MAIN RUN screen when pressure control is active is:
1. Standard MAIN RUN screen first line showing
measured pressure and active Q-RPT.
Always shows measured pressure.
2. Actual pressure rate of change (
<R>
) at all
times.
3. Current control mode indicator. Flashes when
automated pressure control is active.
Character is
<R>
for ramp control.
<C>
is
appended if custom control parameters are in
use.
25.377 MPa a HI
R 1.015/s R
Observe the Ready/Not Ready indicator LED (see Section 3.2.3) for indication of
when the target rate has been established within the rate hold limit. PPCH-G
continues controlling following ramp pressure control protocol (see Section
3.2.2.5) until automated pressure control is interrupted.