D U N I W A Y S T O C K R O O M C O R P .
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shuts the set point off. The next increment is to 1.0 x 10
-9
Torr.
SET
PT
1
LOW
operates in conjunction with
SET
PT
1
HIGH
.
NOTE
The High and Low set point allow the user to set the hysteresis of the set
point operation. As the system is pumped down, the set point relay will be
energized (set point turns on) as the pressure drops below
SET
PT
1
LOW
. The
relay will remain energized until the pressure rises above
SET
PT
1
HIGH
.
It is not possible to adjust the High set point to be lower than the Low set
point. If you adjust the High set point below the pressure previously selected
for the Low set point, the 921 will automatically reduce the value for the
Low set point so that it is the next increment lower than that of the High set
point.
3.
Set Pt 2 High
This operates in the same manner as
SET
PT
1
HIGH
, described above.
4.
Set Pt 2 Low
This operates in the same manner as
SET
PT
1
LOW
, described above.
5.
Torr/mBar
This allows selection of the units to be used in display of the pressure. Press either the
RAISE
or
LOWER
buttons to alternate between Torr and mBar.
6.
Calibrate
This allows the user to modify the reading for either gauge by multiplying by a value between
0.500 and 2.000. This is convenient for calibration of the gauge or for making adjustments for
different gas factors. We suggest you use this adjustment only if you have reliable calibration da-
ta. The multiplier is internal, and is not seen by the user. The digital display shows the result of
the pressure multiplied by the internal multiplier.
7.
Reset of Stored Values
This allows you to recover the factory settings for all stored values and resets the
SET
POINTS
to
off. For a system that is far out of calibration, the factory settings provide a good starting point
for re-calibrating or adjusting the gauge controller. To recover the factory settings, unplug the 921
from its power source. Press and hold
RAISE
and
LOWER
buttons at the same time; while holding
the
RAISE
and
LOWER
buttons depressed, plug the power cord in. You will hear a few short
‘chirps’ from the loudspeaker confirming the factory settings have been entered. The digital dis-
play will show
RST
to confirm the reset has been entered.
8.
Set Point Operation
See description of operation under Front Panel Controls.
TELEPHONE: 650-969-8811 TOLL-FREE (U.S. only): 800-446-8811 FAX: 650-965-0764 EMAIL: [email protected]
www.duniway.com
