Inficon VGC083A - 7.5 IG 1.8-8.7 V Analog Output

tinb29e1-c (2019-10) VGC083A_B.om 55
When the analog output is setup, as described in section 6.5.6, for IG 1.8 – 8.7V,
the analog output voltage represents the pressured measured by the IG for nitro-
gen/air only. Refer to section 8.3.1 if you are using a gas other than nitrogen/air.
Analog output: IG Log-linear 0 to 9.259 Vdc, 0.8 V per decade
The log-linear output signal and pressure are related by the
following formulas:
P (Torr)= 10
((1.25* volts) - 12.875)
V= 10.3 + (0.8)×log
10
(P)
P (mbar)= 10
((1.25*volts) - 12.75)
V= 10.2 + (0.8)×log
10
(P)
P (pascals) = 10
((1.25*volts) - 10.75)
V= 8.6 + (0.8)×log
10
(P)
Where P is the pressure and V is the output signal in volts.
Notes: The output voltage will switch to above
+11 V (dc) under the following conditions:
1) The IG sensor is turned off or any IG fault condition.
2) The pressure exceeds 1.00 × 10
-3
Torr at 100 µA
emission current, 5.00 × 10
-4
Torr at 4 mA emission current,
1.00 × 10
-4
Torr at 10 mA emission current for BAG05x
series ion gauges.
Pressure
[Torr]
Voltage
[V (dc)]
2.00E-11
1.741
4.20E-11
2.0
7.50E-10
3.0
1.30E-8
4.0
2.40E-7
5.0
4.20E-6
6.0
7.50E-5
7.0
1.30E-3
8.0
5.00E-2
9.698
filament is
OFF
≥11
The following chart shows the graphical results of table and formulas above for
pressure measurements in Torr. Pressure is plotted on the X-axis with a log scale;
the output signal is plotted on the Y-axis on a linear scale.
7.5 Analog Output for IG 1.8
- 8.7 V (Nitrogen / Air
only)