tina14e1-a (2017-12) PEG100.om
13
In the case of the Penning method of measurement one only may draw conclu-
sions as to proper functioning while the gauge is in the measurement mode, i.e.
when the gas discharge is running.
Trouble-free operation ("READY" LED (6/2) is on, status output HIGH) is marked
by the presence of a pressure dependent signal starting at a pressure of about
3×10
-9
mbar up to the range limit of 1×10
-2
mbar. When the pressure drops
< 3×10
-9
mbar this status is also maintained.
When the “READY” LED (6/2) is not on, status output 0 V:
Cause 1: When the high voltage was switched on the pressure was below
p <3×10
-9
mbar.
Cause 2: No ignition of the gas discharge, even if the power supply voltage is
present, the high tension has been switched on and a pressure between
about 3×10
-9
mbar and 1×10
-2
mbar.
WARNING
Before baking out the sensing cell you must detach the electronics
assembly from the sensing cell. The electronics assembly may be
damaged when exceeding a temperature of 70 °C.
Before baking out, you must make sure that an ultra sealing disc
(PEG100, DN 25 KF) or a copper seal (PEG100, DN 40 CF) is used
as the flange seal.
The PEG100 is equipped with all-metal sensing cells so that any outgassing
caused by polymer seals is entirely avoided.
After having detached the electronics (refer to Section 5.2.1) from the sensing cell,
the outgassing rate of the sensing cell may be reduced considerably by baking out,
so that the accuracy of the measurements in the range below 1×10
-6
mbar is im-
proved.
When using the gauge chiefly in the UHV range (< 10
-8
mbar) it is recommended to
remove the cathode plate. This helps to reduce the surface area of the surfaces
which may release gas.
How to proceed in order to detach the electronics assembly is described in Section
5.2 (cleaning of the sensor).
Permissible bake out temperature:
Sensing cell of the PEG100 (DN 25 KF) 150 °C (with ultra sealing disc)
Sensing cell of the PEG100 (DN 40 CF) 350 °C
4.2 Measurement System
Status Indication
4.3 Degassing
