3. OPERATION
Page 67
© 2009 DH Instruments, a Fluke Company
The jog step setting is range specific. A jog step setting made in one range does NOT
affect other ranges.
3.4.4
<4UL> (UPPER LIMIT)
PURPOSE
To set the upper limit pressure value for a pressure range and measurement mode.
PRINCIPLE
The UPPER LIMIT function allows the setting of a maximum pressure not to be exceeded
when using a specific range and measurement mode. Absolute and gauge measurement
modes (see Section 3.3.3,
PRINCIPLE) have their own, specific limits.
Automated pressure control targets greater than the upper limit are not accepted. When the
pressure measured by PPCH exceeds the upper limit, automated or direct manual pressure
control is aborted and an intermittent warning beep sounds.
The UPPER LIMIT function is most often used to protect the device or system connected to
the PPCH
TEST
port from accidental overpressure.
The default upper limit is 105 % of AutoRange span or 102 % of Q-RPT default (maximum)
full scale, whichever is lower.
The upper limit is very useful in assuring that the pressure ramps of monotonic or ramp
pressure control modes do not result in an accidental overpressure.
OPERATION
To view or edit the upper limit press
[SETUP]
,
<4UL>
.
The display is:
1. Entry field for upper limit value in active pressure unit of
measure and measurement mode.
Upper limit: IH
204.000 MPa a
Edit the upper limit value as desired. The maximum upper limit is 105 % of AutoRange range
or 102 % of default QRPT range, whichever is lower. Press
[ENT]
to return to the MAIN
RUN screen with the new upper limit active. Press
[ESC]
to return to the MAIN RUN screen
with no change to the upper limit.
When the upper limit has been exceeded, the display of current pressure flashes and a
buzzer sounds at 2 second intervals. To return to normal operation, reduce pressure using
direct pressure control keys or an automated pressure command.
Upper limit values are specific to each range and measurement mode. Be careful not to
assume that the upper limit set in one measurement mode will apply to the other.
For example, if you set 100 MPa as the upper limit in gauge mode, the upper limit will not be 100
MPa in absolute mode of the same range.
