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Page 27
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Operation
D397-21-880 Issue G
4.8.8
Active Ion Gauge (AIGX-S) control
Note:
TIC does not support the AIGX-D variant of the AIGX range.
Note:
For a detailed specification and instructions regarding the use of the AIGX, refer to the Instruction Manual
(D048-50-880).
The Active Ion Gauge (AIGX-S) is a fully integrated active instrument, with a measuring range of 6.6 x 10
-2
to 6.6 x
10
-10
mbar (5 x 10
-2
to 5 x 10
-10
Torr). The gauge has a 1 volt/decade linear output in the range 0 to 10 V d.c. The
AIGX-S is supplied with two filaments, which may be manually selected at the gauge head. For maximum filament
life, the gauge includes automatic emission current switching and high-pressure shutdown. The only user selectable
features are a setpoint and degas facility.
The gauge also includes a comprehensive range of diagnostic outputs, which are displayed on TIC.
AIGX has menu options in addition to those shown. (Refer to Default setup options (all gauges)
Table 17 - Error/diagnostic monitoring AIM
Diagnostic messages
Description
Over Range
(Gauge output
>
11.000 V)
Indicates that the measured gas pressure is outside the range of the gauge or the
wrong gas type has been selected.
Check the gas selected is correct, switch off the gauge, clear the error, reduce the
process pressure to within the range of the gauge and press 'Cycle'.
If the error persists, there is a fault with the gauge and the electronics module
should be replaced.
Under Range
(Gauge output
<
0.025 V)
Indicates that there is a fault with the gauge or cable. Replace the cable and if the
fault persists, the electronics module should be replaced.
Striking
Indicates that the gauge is attempting to strike.
TIC will continue in this mode for up to 15 minutes.
Not Struck
Indicates that the gauge failed to strike within 15 minutes.
This is most likely to be because of the gauge tube becoming contaminated. The
gauge tube should be inspected for signs of contamination or debris. If the anode
and cathode are not bright, the gauge should be cleaned or the electrodes
replaced (D145-45-802 or D146-61-802) as described in the AIM instruction manual.
Table 18 - Setup options AIGX
Menu option
Description
Degas
Allows the user to degas the gauge.
'Scroll' to 'Degas' and press 'Select'.
'Command Sent' appears for 1 s to confirm degas sequence initiated.
Note:
Whilst the gauge is degassing, the pressure output may read slightly higher
than normal.
The maximum duration of the degas cycle is 3 minutes, during which the pressure
shown on the 'View' screen will be suffixed with a 'DG' e.g. 1.67
DG
- 09.
At the end of the cycle, the gauge will automatically return to its normal operating
mode.
If the pressure rises above 1.3 x 10
-4
mbar (1 x 10
-4
Torr) during the cycle, degas
will automatically stop until the pressure falls below 4 x 10
-5
mbar
(3 x 10
-5
Torr), at which point degas resumes for the remainder of the cycle.
Note:
There is no facility enabling degas to be manually switched off mid-cycle.
