Instruction Manual WGM701 Wasp
InstruTech
Page 14
4.3
Status Indication
DIA
ADJ
CAL
HV-ST
ST
E
C
A
0 2
4
6
8
Supply voltage
Error
High voltage
cold cathode
For factory
setting only
Calibration
value
LED
Condition
<ST>
<HV-ST>
off
off
No supply voltage
lit solid green
off
Supply voltage = ok, Pirani active,
no high voltage in the measuring
chamber
lit solid green
blinking
green
Supply voltage = ok,
pressure in the cold cathode range,
cold cathode has not ignited
lit solid green
lit solid
green
Cold cathode has ignited
blinking red
off
EEPROM error
4.4
Gauge Adjustment
•
The cold cathode measuring circuit, which is dominant for low pressures (< 7.6 ×10
-4
Torr), is factory-calibrated
and cannot be adjusted. The HV (zero) adjustment of the Pirani measuring circuit is carried out automatically
by the gauge itself at pressures less than 7.6 ×10
-6
Torr. A new zero point is saved in a non-volatile memory
every 15 minutes. Any zero adjustment has a negligible effect on the pressure range between approx. 7.6
×10
-3
Torr and 7.5 x 10
2
Torr.
•
The characteristic curve of the Pirani can be affected if used under different climatic conditions, through
extreme temperatures, aging or contamination. If necessary the user can manually readjust the Pirani gauge
as described below:
