™/S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
© 1995 - 2010 Fluke Corporation, DH Instruments Division
Page 102
3.6.3.1
Upper Limit Alarm and Sequence
When the pressure reaches the upper limit, continues normal
operation but sounds an audible alarm. The alarm ceases if the pressure is
decreased below the upper limit.
When pressure reaches the overpressure limit,
all internal valves close, normal
operation ceases and the display indicates:
610.250 kPa 601.780
OVERP! CHK & PWR DWN
The top line indicates the current pressure measurement of the upstream (left)
and downstream (right) RPTs. The bottom line is the over pressure warning.
Pressure indications that are grossly out of scale generally indicate that the
RPT(s) have been fatally over pressured.
Other menus can be observed but the MAIN run screen can not be accessed and
no internal valves can be operated. To return the to normal
operation, it must be turned OFF and back ON or press
[ENTER]
from the
overpressure screen. When normal operation is reestablished, its
isolation valves will open. Be sure the situation that led to the overpressure
condition is corrected before attempting to reestablish normal operation.
Note
•
The upper limit and overpressure functions are intended to
use ’s features to the extent possible to protect the
reference pressure transducer (RPTs) against
overpressure. The system is not failsafe and an
overpressure causing fatal damage to the RPTs can
still occur. Ultimately, protection of the RPTs is the
responsibility of the user. RPTs damaged by overpressure
are not covered under the product warranty.
•
continuously monitors for maximum pressure.
Whenever the overpressure limit is exceeded, the pressure
value reached, time and date are logged to a
privileged location. This information can be of use in
determining the events that led to an overpressure situation.
3.6.4
<4cal>
To calibrate and adjust the reference pressure transducers, ohmic measurement
system, optional MFC control function and the calibrated molbloc flow.
The CALIBRATION functions are considered part of maintenance and are
therefore covered in the maintenance section of this manual (see Section 1).
3.6.5
<5Prefs>
PURPOSE
To access a menu of internal operational preferences and functions.
These include:
<1ScrSvr>
View and change the SCREEN SAVER function (see Section 3.6.5.1).
<2ID>
View and edit the user ID (see Section 3.6.5.2).
<3time>
View and edit the internal time and date settings (see Section 3.6.5.3).
