946 Controller Instruction Manual
pg. 33
3. Range
The full-scale pressure range of the capacitance manometer in use needs to be set. Capacitance
manometers with full scale (ranges) from 1x10
-2
to 1x10
+4
Torr can be operated. Only 3
selections are available in each decade (1, 2, and 5), except between 1,000 to 10,000 Torr where
1500 Torr is allowed.
For a Manometer with pressure unit other than Torr (such as 1000 mBar full scale), change the
controller pressure unit to match the pressure unit of the manometer (such as mBar) before
selecting the appropriate range.
Setup CM Gauge A1
Range
Auto Zero
Relay
Relay 02
Relay 01
1.00E+03
Enable
DIR
SET SP
ABOVE
Hyst
SET
1.00E+01
9.35E+00
BELOW
ENABLE
3.00E+01
5.35E+01
NA
Factory Default
NO
Manual Zero
NO
Message
Box
Auto-detected
Auto-detected
CM Type
Input Voltage
5U V
DIFF
Operation Voltage:
+/-15V
Figure 6-8 Capacitance Manometer Setup Information Screen
4. Factory Default
When YES is selected and entered for Factory Default, any Manual Zero data is removed.
5. Auto Zero
This selects a sensor for autozeroing of the capacitance manometer. Suitable sensors and their
channels are autodetected. NA which can be selected if Auto Zero is not required.
The Auto Zero will be executed only when:
(1) System pressure is less than 10
-5
xP
FS
(5 decades lower than the full scale)
(2) The CM reading is between 5x10
-4
xP
FS
and 0.05xP
FS
(0.05% to 5% of the full scale)
When a Capacitance Manometer has been zeroed, a U will be displayed under the gauge type
indicator (CM) of the zeroed channel to indicate this.
Table 6-1 shows the valid gauges that can be used for autozeroing based on the full-scale rating
of the capacitance manometer.