Thyracont VD10, Руководство по эксплуатации

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vd10s8-de-131129
degas : Degas-function for hot cathode sensor
Deposition or adsorbed gas molecules on the electrodes of a hot cath-
ode sensor (VSH) may lead to increased degassing in ultrahigh vacuum
or even cause instabilities of the measurement signal. In such cases it is
appropriate to clean the anode of the sensor by degassing. This is done
at pressures below 2.0x10
-6
mbar by ohmic heating of the anode to tem-
peratures around 800°C.
For degassing the sensor set the degas parameter to "on" and confirm
with the set-key. The degas procedure will stop automatically after ap-
prox. 3 minutes, but can be cancelled any time by setting the parameter
to "off" again.
During the degas process no actual pressure measurement is
available!
The degas function cannot be started if the hot cathode is dis-
abled (fil "off").
adjust : Transducer adjustment
The transducers are adjusted ex works with 24V voltage supply in
upright position, flange to the bottom.
Other orientation, operation under different climatic conditions, ex-
treme temperature changes, ageing or contamination can result in
the need for readjustment of the Pirani sensor.
For transducers VSM and VSH with combination sensors the
adjustment does only affect the Pirani sensor. Hot and cold
cathode sensors are not readjusted.
To achieve optimum results of the adjustment we recommend
to consider a warm-up of at least 5 minutes at the appropriate
calibration pressure before any adjustment.
For zero adjustment actual pressure should be less than
5,0x10
-5
mbar.
For adjustment on atmosphere pressure set the parameter to "Hi" and
confirm with the set-key.
For adjustment on zero pressure set the parameter to "Lo" and confirm
with the set-key.