3. OPERATION
Page 63
© 2007 DH Instruments, a Fluke Company
When a control mode is selected using the CONTROL function, CONTROL parameters are
automatically set to default values for that control mode in the active range (see Table 8 for
definition of PPCH-G default control parameters). The default control parameters are those
best suited to operate within PPCH-G pressure control and measurement specifications for a
given range of operation.
Control mode parameters can be viewed and customized in the CONTROL function
(see Section 3.4.6). Customizing the control parameters changes the conditions required for
a
Ready
condition to occur (see Section 3.2.3). This can be used to increase control speed
(reduce time to
Ready
), usually by decreasing control precision, or to increase precision which
usually decreases control speed. For example, changing the dynamic pressure control hold
limit from its default value of ± 0.01 % of the active range to ± 0.05 % of the active range
decreases the time required to set a pressure since the limit within which the pressure must
be set has increased. However, it will also increase the maximum possible control error when
Ready
is indicated.
Table 8.
Default pressure control parameters
HOLD LIMIT
PRESSURE
STABILITY LIMIT
PRESSURE
TARGET LIMIT
RATE LIMIT
DYNAMIC
MODE
(standard and
hi volume)
± 0.01 % of active
range, or 0.003 % of
Q-RPT maximum
span, whichever is
greater
Not applicable
Not applicable
Not applicable
STATIC MODE
± 1 % of active range
± 0.005 % of active
range or 2 ppm of
Q-RPT maximum
span/second,
whichever is greater
Not applicable
Not applicable
MONOTONIC
MODE
Not applicable
Not applicable
1 % of Q-RPT
maximum span
0.05 % of Q-RPT
maximum span/second
RAMP MODE
± 25 % of target rate
Not applicable
Not applicable
Not applicable
PG MODE
(use with
PG7202
piston gauge
only)
± 0.01 % of active
range, or 0.003 % of
Q-RPT maximum
span, whichever is
greater
Not applicable
Not applicable
Not applicable
CONTROL
IDLE
Not applicable
± 0.005 % of active
range or 2 ppm of
Q-RPT maximum
range/second,
whichever is greater
Not applicable
Not applicable
*Note: % of range limits are of default or AutoRanged range.
OPERATION
To access the CONTROL function, press
[SETUP]
,
<6control>
. The display is:
1.
Control mode that is currently active.
2.
Active Q-RPT indicator.
3.
Selection to adjust limits of active control mode (
<1limits>
)
or
select a control mode (
<2mode>
).
Dynamic,standard IH
1limits 2mode
Select
<1limits>
to view or edit the active control limits for the active control mode (see
Section 3.4.6.1).
Select
<2mode>
to change the active control mode (see Section 3.4.6.2).
