© Arun Microelectronics Ltd 2020. All rights reserved
Page 16
Autostart mode
Automatically start and stop IG1 or IG2 based on Autostart
gauge pressure. If Autostart criteria are met, start and stop IG1
based on external inhibit signal.
Only applicable to IG1 and IG2 Function Switch positions. In
BAKE or DEGAS Function Switch positions, the behaviour is as
Manual mode.
•
An Autostart gauge is selected, either Pirani 1 or
Active Gauge.
•
An Autostart pressure is specified.
•
When the Autostart gauge pressure is less than the
Autostart pressure, the Ion Gauge will start
automatically.
•
If the Autostart gauge pressure rises above the
threshold:
P > 10
(log
10
𝐴𝑠𝑃) +0.3
Where
P
is the Autostart gauge pressure and
𝐴𝑠𝑃
is
the Autostart pressure, then emission is suspended
and the display alternates between showing the
Autostart gauge pressure and an Autostart warning
message. Emission will restart when the Autostart
gauge pressure falls below the Autostart pressure.
•
External inhibit is not considered a fault. If external
inhibit is present, a warning message is displayed and
emission is suspended. Once external inhibit is
removed and Autostart gauge pressure is below the
Autostart pressure, emission will resume.
•
Functions at startup. If the Function Switch is in IG1 or
IG2 position at startup, the Ion Gauge will start,
provided the Autostart criteria as described above are
met.
•
If the Interlock gauge is not switched on (Pirani 1) or
not used (Active Gauge) then a warning message is
shown and emission cannot be started.
•
If the Interlock gauge is Pirani 1, and Pirani 1 fails
open circuit, emission will be aborted if in progress, or
prevented from starting. This is considered a fault
condition, requiring the Function Switch to be
returned to OFF before another attempt can be made
to start emission.
External Inhibit mode
Summary of Contents for NGC3
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