PPCH-G™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company
Page 28
Note: Target is a rate of change value (pressure/time), not a pressure value
Figure 13.
Ramp pressure control operation
PPCH-G includes a
Ready/Not Ready
feature that indicates when current
pressure control requirements have been met (see Section 3.2.3).
With ramp pressure control active, a
Ready
condition occurs whenever:
•
PPCH-G is controlling rate at the target rate value within the rate hold limit.
Figure 14 illustrates
Ready/Not Ready
operation in ramp control mode.
Note: Target is a rate of change value (pressure/time), not a pressure value
Figure 14.
Ready/Not Ready
in ramp pressure control mode
3.2.2.6
PG CONTROL
PG control
mode should not be used in normal PPCH-G stand-alone operation.
It is used by a PG7202 piston gauge to automate its pressure control using the
AutoGen function (see the PG7000 Operation and Maintenance Manual).
In PG control mode, the PPCH-G uses its control valves to adjust pressure very
near to the pressure at which the piston gauge piston floats. It then uses the
thermal pressure control unit (TPCU) to float the piston.
