PPCH-G™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company
Page 56
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.
3.3.10.5
PG CONTROL MODE, [ENT/SET P]
PG control is not to be used for regular PPCH-G stand alone operation. It
should only be used by a PG7202 piston gauge AutoGen function.
PG control mode is not to be used for regular PPCH-G stand alone operation. It
is used only by a PG7202 piston to automated pressure control using the
AutoGen function (see PG7000 Operation and Maintenance Manual).
If the PPCH-G is operated locally or remotely in PG control mode, operation
appears identical to hi volume dynamic mode (see Section 3.2.2.2
)
but the
thermal pressure control unit (TPCU) is active and may affect pressure stability,
especially when not actively controlling pressure.
When PG control mode is active, the main run screen control character is
<P>
.
3.3.10.6
INTERRUPTING AUTOMATED PRESSURE CONTROL
Automated pressure control is interrupted by:
•
Pressing [ESC]:
Suspends control and remains in MAIN RUN screen.
Does not vent pressure. PPCH-G passively measures the pressure applied
to its
TEST
port. Pressure may take some time to stabilize if control mode is
dynamic as thermal pressure control unit stabilizes.
•
Pressing any direct pressure control key other than the jog keys (see
Section
3.1.3
):
Suspends control and executes direct pressure control.
•
Pressing any function key:
Suspends control and goes to the selected
function. Does not vent pressure. PPCH-G passively measures the
pressure.
•
Pressing [ENT/SET P]:
In dynamic, static and ramp modes
, suspends
control and goes to ENTER target screen. Does not vent pressure. PPCH-G
passively measures the pressure.
In monotonic mode
,
[ENT/SET P]
suspends control only if the pressure has not yet reached the target limit.
[ENT/SET P]
does not suspend control during the slow ramp after the target
pressure has been reached. This is to avoid suspending control when setting
the next pressure increment as that could cause the direction of pressure
evolution to reverse, violating the monotonic excursion.
•
Sending any remote command when in local mode
interrupts pressure
control.
To resume automated pressure control, press
[ENT/SET P]
and ENTER a target
pressure value.
