PPCH-G™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company
Page 54
The
[
] and [
] direct pressure control keys can be used in static mode
while the PPCH-G is waiting for pressure stability to jog the pressure by the pressure
step value. (see Section 3.1.3). These keys also jog the target value when in the
ENTER target value screen.
3.3.10.3
MONOTONIC CONTROL MODE, [ENT/SET P]
If the PPCH-G is not set for monotonic control, use
SPECIAL, <6control>
,
<2mode>
to select monotonic control mode.
Use monotonic control with caution. Once pressure is set to the target, an
ascending monotonic ramp will continue 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 pressure control target
pressure in current pressure unit of measure.
20.007 MPa g HI
Target:40.0
Edit the target pressure value as desired.
A target pressure entry that exceeds the current upper limit (see Section
3.4.4) is not accepted. Negative values are not accepted. See Section 3.3.10.6 for
information on zero target commands.
Press
[ENT/SET P]
to start pressure control to the target pressure 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.
Current control mode indicator. Flashes when
automated pressure control is active.
Character is
<M>
for monotonic control.
<C>
is appended if custom control parameters are
in use.
3.
Target pressure value (
<T>
) at all times.
39.998 MPa a HI
T 40.000 M
Observe the
Ready/Not Ready
indicator LED (see Section 3.2.3) for indication of
when the controlled pressure is at the target pressure and under the monotonic
ramp rate target. PPCH-G continues controlling following monotonic pressure
control protocol (see Section 3.2.2.4) until automated pressure control is interrupted.
