DH Instruments PPCH-G, Руководство по эксплуатации и обслуживанию

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3. OPERATION
Page 23 © 2007 DH Instruments, a Fluke Company
3.2.2 AUTOMATED PRESSURE CONTROL
PPCH-G automated pressure control automatically sets and controls pressure to a user
designated target value or ramp rate.
See Section 3.3.10 for information on using [ENT/SET P] to set pressure automatically and
abort automated pressure control.
PPCH-G supports five pressure control modes to meet different pressure setting and
controlling requirements: dynamic, static, monotonic, ramp and PG. Pressure control
parameters for each control mode are automatically set to optimal default values for the
operating PPCH-G range when the range is selected or AutoRange is used (see Section
3.3.4). Control parameters can be customized using the
[SETUP]
,
<6control>
function (see
Section 3.4.6.1).
The PPCH-G pressure control modes are:
Idle, no control
Measure pressure with no control of the pressure value or evolution (see
Section 3.2.2.1).
Dynamic control
Set pressure to a target pressure value and actively maintains that value
(see Section 3.2.2.2).
Static control
Set pressure to a target value and stop all control to let pressure stabilize
naturally without control interference. Readjust only if pressure goes out
of hold limit (see Section 3.2.2.3).
Monotonic control
Near a target pressure value, set a low rate pressure ramp continuing in
the same direction as that in which the pressure was set. Always
controls pressure in one direction (see Section 3.2.2.4).
Ramp control
Set rate of change of pressure to a target rate of change value. There is
no target pressure value (see Section 3.2.2.5).
PG control
Not used in normal stand-alone PPCH-G operation. Used only by the
automated pressure control function of a PG7202 piston gauge when
PPCH-G is used to automate PG7202 pressure control (see Section
3.2.2.6).
See this Section 3.2.2, and Sections 3.2.2.1 to 3.2.2.5 for a detailed explanation of each control
mode and its advantages, the default control parameters and the control customization options.
3.2.2.1 IDLE, NO AUTOMATED CONTROL (MEASURE MODE)
In any control mode, PPCH-G pressure control can be interrupted so that no
control occurs. Control inactive is indicated by the pressure control indicator
characters on the MAIN RUN screen NOT flashing. The control character(s)
is/are the two characters in the center of the bottom line of the display (see
Section 3.1.1).
To abort control when control is active press
[ENT/Set P]
,
[ESC]
,
[VENT]
,
[ ]
or
[ ]
.
[ENT/Set P]
does NOT abort control in monotonic mode.
When control is idle (measure mode), a Ready condition occurs any time the
pressure stability test is met (see Section 3.2.3).