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vd12-14-de-171016
"off" ionization sensor disabled
"on" automatic control of the ionization sensor
With disabled ionization sensor transducers VSM and VSH behave
like a Pirani transducer with range 1000 - 1x10
-4
mbar. Correspond-
ingly the output "ur" in this case means that actual pressure is below
1x10
-4
mbar.
Settings made under HCSens/CCSens are only temporarily
saved in the transducer memory. After mains supply is
switched off or disconnected the transducer will always be in
mode "ionization sensor enabled" !
trMode: Select transition mode
For transducers with combination sensors you can select whether a
hard switch-over ("switch") or a continuous transition ("trans" or
"trans_hi"/"trans_lo") between the two sensors should be performed
in the overlap range.
Detailed information about each mode can be found in the operating
manual of the transducer.
degas: Degas-function for hot cathode sensor
Deposition or adsorbed gas molecules on the electrodes of a hot cathode
sensor (VSH) may lead to increased degassing in ultrahigh vacuum or
even cause instabilities of the measurement signal. In such cases it is ap-
propriate 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 temper-
atures 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 approx.
3 minutes, but can be cancelled any time by setting the parameter to "off"
again.
The degas function cannot be started if the hot cathode is disa-
bled (fil "off").
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