LEYBOLD 157 89, Руководство пользователя

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selected on parameter page 5.
LOCK
The LOCK message comes on, when the entry of para-
meters via the keyboard has been locked. For this refer
to Section 2.3.9.2.
PARA
The PARA message comes on, when entering instru-
ment parameters. The entered instrument parameters
apply to the currently selected and displayed measure-
ment channel.
2.3.5 Keys TM 1, TM 2 and PM
Pressing key TM 1, TM 2 or PM selects the correspon-
ding measurement channel. The pressure of the selected
measurement channel is then displayed by displays (3/2)
and (3/3).
The trigger and chart recorder outputs of all channels
present is not influenced in any way by the selection of a
particular measurement channel.
2.3.6 Key HV
The HV key (4/1) is used to switch the high voltage for
the PM channel on and off.
After switching on the PM high voltage a value is indica-
ted immediately, provided the PM channel has been sel-
ected. 10 s after switching on the high voltage the instru-
ment checks whether the gauge tube has ignited and
whether the pressure has risen above 5·10
-9
mbar. As
long as these conditions have not been met „FAIL“ will be
displayed and the triggers will not be active.
However, if these conditions have been met once after
switching on, the instrument will indicate that it is ready.
Thereafter the triggers are active, independently of the
pressure, cable or sensor conditions until the high volta-
ge is switched off again.
Warning
Even in the presence of an error messa-
ge the PM high voltage (3.3 kV) will
remain switched on.
Note
- PENNINGVAC gauges should only be switched on at
pressures below 1·10
-2
mbar. Due to the physical prin-
ciple employed, any PENNINGVAC gauge can be swit-
ched on at higher pressures (HV-on).
- After switching on the high tension, the gas discharge
is started in the sensor with a voltage of 3.3 kV. After
successful ignition this voltage is then reduced to an
1.6 kV operating level. This increases the service life of
the sensors, in particular in connection with argon
atmospheres.
When switching on the PENNINGVAC gauge at pressu-
res over 1·10
-2
mbar the display will indicate an unspeci-
fied value. Prolonged operation in this unpermitted pres-
sure range may lead to increased contamination of the
gauge.
More details on the operation of this key are given on
parameter page 7 „Switching the PENNINGVAC on and
off automatically“.
11
Fig. 4 Partial view of the front panel
Key to fig. 4
1 Key HV
2 Key PM
3 Key TM 2
4 Key TM 1
5 Status display area
6 Key decrement
6