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3 putting the gauge into operation 4.4 degas – INFICON BCG450 ATM to Ultra-High Vacuum Triple Gauge User Manual

Page 28

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tina40e1-b (2011-04)

When the operating voltage is supplied (

→ Technical Data), the output signal is

available between Pin 2 (+) and Pin 12 (–) of the sensor cable connector
(Relationship Output Signal – Pressure

→ Appendix A).

Allow for a stabilizing time of approx. 10 min. Once the gauge has been switched
on, permanently leave it on irrespective of the pressure.
Communication via the digital interfaces is described in separate sections of this
document.


Gauge failures due to contamination or wear and tear, as well as

expendable parts (e.g. filament), are not covered by the warranty.

Deposits on the electrode system of the BA sensor can lead to unstable measure-
ment readings.
The degas process allows in-situ cleaning of the electrode system by heating the
electron collector grid to approx. 700 °C by electron bombardment.
Depending on the application, this function can be activated by the system control
via one of the gauges digital interfaces. The BCG450 automatically terminates the
degas process after 3 minutes, if it has not been stopped before.

The degas process should be run at pressures below 7.2×10

-6

mbar

(emission current 5 mA).

For a repeated degas process, the control signal first has to change from On
(+24 V) to Off (0 V), to then start degas again with a new On (+24 V) command. It
is recommended that the degas signal be set to Off again by the system control
after 3 minutes of degassing, to achieve an unambiguous operating status.

A new degas cycle can only be started after a waiting time of

30 minutes.



4.3 Putting the Gauge Into

Operation

4.4 Degas

Contamination