INFICON VGC403 Three-Channel Measurement and Control Unit - Manual (Page 24)

24
tinb07e1-e 2011-07 Vacuum Gauge Controller
5.2.2 Gas type (GAS)
Sensors are normally calibrated for a measurement in
nitrogen or in air. The GAS parameter is used to configure
the channel to other gas types.
Tab. 5-4 GAS parameter settings
Cor
If you want to perform pressure measurements in a gas
type without a fixed correction factor, you may multiply
the pressure reading with a variable correction factor. To
this end proceed as follows:
1 Set the GAS parameter to Cor
2 Press the PARA button
• The correction factor is displayed
3 Use the arrow buttons the modify the correction
factor
• The value of the parameter is changed
• The COR indicator is illuminated
You can adjust the correction factor of a sensor in the
range 0.10…9.99. The setting 1.00 returns the uncor-
rected pressure reading.
NOTE:
The gas type correction is effective only for the fol-
lowing pressures: p < 10
-2
mbar (BPG/HPG/MPG sen-
sor), p < 10 mbar (PCG sensor), p < 1 mbar (BCG
sensor).
5.2.3 Measuring range (FS)
Linear sensors (CDG) require specification of the full-
scale range. You can set this value using the cursor but-
tons. The following values are available:
• 0.01 mbar
• 0.01 Torr, 0.02 Torr, 0.05 Torr
• 0.10 mbar, 0.25 mbar, 0.50 mbar
• 0.10 Torr, 0.25 Torr, 0.50 Torr
• 1 mbar, 2 mbar, 5 mbar
• 1 Torr, 2 Torr, 5 Torr
• 10 mbar, 20 mbar, 50 mbar
• 10 Torr, 20 Torr, 50 Torr
• 100 mbar, 200 mbar, 500 mbar
• 100 Torr, 200 Torr, 500 Torr
• 1000 mbar, 1100 mbar
• 1000 Torr
• 2 bar, 5 bar, 10 bar, 50 bar
5.2.4 Offset (oFS)
When the offset correction is activated, a previously
specified offset value will be subtracted from each pres-
sure reading. This allows to conveniently measure the
relative pressure with respect to a reference pressure.
The offset correction affects the readings on the display,
the RS232C output, the recorder output, and the switch-
ing functions. The analog outputs, however, are not
affected.
Establishing an offset value and activating the offset
correction
1 Select the oFS parameter
2 Keep the UP button pressed for approximately 2
seconds
• The current pressure reading becomes the new
offset value
• The offset correction is activated
• The OFS indicator is illuminated
Deactivating the offset correction
1 Select the oFS parameter
2 Press the DOWN button
• The offset correction is deactivated
• The display shows oFF
• The OFS indicator is dark
Activating the offset correction
1 Select the oFS parameter
2 Press the UP button
• The offset correction is activated
• The OFS indicator is illuminated
NOTE:
Always deactivate the offset correction before ad-
justing the offset of a sensor.
Display Significance
n2 Nitrogen or air. No correction of any
kind is required.
Ar Argon. The pressure reading is
determined utilizing a correction fac-
tor for argon. COR is illuminated.
H2 Hydrogen. The pressure reading is
determined utilizing a correction fac-
tor for hydrogen. COR is illumi-
nated.
Cor Other gases. The pressure reading
is determined utilizing a variable
correction factor. COR is illumi-
nated.