3. OPERATION
Page 101
© 1995 - 2010 Fluke Corporation, DH Instruments Division
3.6.3
<3UL>
PURPOSE
To set an upper pressure limit above which will produce a warning, interrupt
operation and isolate its internal pressure transducers.
PRINCIPLE
contains two, high precision reference pressure transducers (RPTs). These can
be fatally damaged by large overpressures. The UL function uses ’s internal
capabilities to attempt to protect the RPTs against overpressure. continuously
monitors the pressure read by the RPTs. When the pressure passes the level set by the UL
function, warns the operator by sounding an audible alarm. Beyond the UL limit
there is an overpressure limit, which is not user selectable. If the pressure reaches the
overpressure limit, uses its internal valves to isolate the RPTs.
OPERATION
To access the Upper Limit (UL) function, press
[SPECIAL]
,
<3ul>
. The display is:
The indication is of the current upper limit setting in the
current pressure unit of measure. To specify a different
pressure unit of measure, use
[SETUP]
,
<8presU>
(see
Section 3.5.8).
Transducer Max Pres:
600.000 kPaa
To change the upper limit, enter the value desired (see max UL limits below) and press
[ENTER]
. The display returns to the MAIN run screen with the new upper limit in effect.
The maximum upper limit settings, which are also the default values, are 5 % above the
maximum operating pressure ranges. For the models, the max UL
values are specifically:
For
A350K:
315 kPa absolute (45 psia)
For
A700K:
630 kPa absolute (91 psia)
For S
A1.4K:
1470 kPa absolute (213 psia)
For S
A2M:
2100 kPa absolute (304 psia)
The overpressure limits, which cannot be edited, are:
For
A350K:
330 kPa absolute (48 psia)
For
A700K:
660 kPa absolute (96 psia)
For S
A1.4K:
1540 kPa absolute (223 psia)
For S
A2M:
2200 kPa absolute (319 psia)
If the overpressure limit is exceeded, all internal valves close and normal operation
is interrupted. Normal operation can be reestablished by turning ’s power OFF and
back ON or pressing
[ENTER]
. Be sure to correct the situation that led to the overpressure
condition prior to rebooting or pressing
[ENTER]
. See Sections 3.6.3.1, 3.1.4 for
additional details.
Note
UL is molbloc channel specific. There are separate UL settings for
molbloc channel A and channel B operation.
