AML NGC3, Руководство пользователя

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© Arun Microelectronics Ltd 2020. All rights reserved Page 21
7. Operation
7.1. Use of the Function Switch in the operating positions
The Function Switch must be stationary for a brief period of time before any action results. This allows you to rotate the
switch through various operating positions without starting the Ion Gauge or other functions. The Ion Gauge will be started
about one second after rotating it to the corresponding IG position. As additional security, Bake or Degas will not start
unless you enter the password (if set) and then select and/or confirm your requirement.
7.2. Relay trip levels
Relay trip levels can be reviewed and modified in the IG1, OFF and IG2 positions of the Function Switch by pressing ENT
when a pressure reading is being displayed. If a password has been set you must enter it to be able to modify settings. If
the password is set and you do not enter it you may view the settings but cannot change them.
If you make no response at any stage of the sequence the display ‘times - out’ to the pressure display that was current
before the start of the sequence and the setting at the interrupted stage is unchanged.
The relay trip levels or their assignment to Bake are displayed
in sequence, starting with Relay A and progressing to Relay D.
The next in the sequence is shown each time that you press
ENT. The status LED for the relay and the numeric setting of
the trip level flash if trip modification is allowed. Modify the
displayed setting by pressing
△
or
▽
, then press ENT to
confirm it and display the next.
Relays assigned to a gauge are energised when the pressure
falls below the “Low” setpoin t.
The assigned relays are de-energised when the pressure rises
above the “High” setpoint. The minimum allowed hysteresis is
10% of the low setpoint.
If a trip level is set at the upper limit of its range the relay is
permanently de-energised. If a trip level is set at the lower limit
of its range the relay is permanently energised. Setting trip
levels at these limits do not cancel the assignment of the relay.
Relays assigned to ‘None’ are de -energised.
The maximum setting for any relay assigned to the Ion Gauge
is half the overpressure trip setting. Changing the overpressure
trip may cause the status of relays assigned to the Ion Gauge
to change if the current pressure is between the former and
new overpressure, after emission is re-started.
Numeric values of trip levels will change automatically if the
units of measurement are changed, in order to maintain the
trip levels at the same pressures.