DH Instruments PPCK PLUS, Operation And Maintenance Manual

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PPCK+™ Operation and Maintenance Manual
Page 25
©2001 DH Instruments, Inc .
3.1.2.5 PRESSURE READY /NOT READY
PPCK+ provides a Ready/Not Ready indication. This indication is intended to
provide the user with a clear and objective criterion for determining when a valid
pressure measurement can be made. On the main run screen, the far left character
of the top display lines indicates
Ready / Not Ready . In remote command responses,
Ready / Not Ready is indicated by “R” or “NR” in the response string.
Ready / Not Ready front panel display indications are:
•
<*>: Pressure Ready .
•
<
↓
>: Pressure Not Ready and decreasing.
•
<
↑
>: Pressure Not Ready and increasing.
When pressure control is NOT active: A Ready condition occurs any time the
pressure rate of change is inside the stability limit. The stability limit is defined in
terms of rate of change of pressure in current pressure units per second (see
Section 3.2.6).
When pressure control is active: The criteria for determining the Ready / Not
Ready condition depend on whether the current control mode is static or dynamic .
Pressure Ready / Not Ready parameters are set by default when a control mode
is selected. The parameters can be customized if desired (see Sections 3.2.3
and 3.2.6).
The Ready condition is handled specially when responding to an automated pressure
command of zero (see Section 3.2.10.1).