Ion Gauge Plus Convection Gauge Analog Output - Ig + Cg1 - Instrutech The Hornet IGM402 User Manual

Instruction Manual

Ion gauge plus convection gauge analog output - IG + CG1

6.2
ANALOG MODE in SETUP IG menu is set to IG + CG1. LOG-LINEAR 0.5 to 7 Vdc, 0.5 V/decade (N
When IG + CG1 is selected, this setting combines the measurements from IG and CG1 to provide full range vacuum
measurement. The analog output in this case is proportional to pressure from 1 x 10
A) The log-linear output signal and pressure are related by the
following formulas when units of measurement is in Torr and
mbar:
(volts – 5.5)/(0.5)
P = 10
Where P is the pressure in Torr or mbar, and V is the output
signal in volts.
B) The log-linear output signal and pressure are related by the
following formulas when units of measurement is in pascals:
(volts - 4.5)/(0.5)
P = 10
Notes - The output voltage will switch to above +10 Vdc
under the following conditions:
1) The filament is turned off or any other IG fault condition
while CG1 is damaged or disconnected.
2) The pressure exceeds 1.00 x 10
-2
current or 5.0 x 10 Torr at 100 µA emission current and CG1
is damaged or disconnected.
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.
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
1.0E-10
InstruTech
V = ((0.5 X log (P)) + 5.5
10
V = ((0.5 X log (P)) + 4.5
10
-3
Torr at 4 mA emission
Log-Linear Analog Voltage to Pressure
1.0E-09 1.0E-08 1.0E-07 1.0E-06 1.0E-05
-9
Log-Linear Analog Output (N
Pressure (Torr)
1.0E-10
1.0E-09
1.0E-08
1.0E-07
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
1.0E+01
1.0E+02
1.0E+03
See Notes
1.0E-04 1.0E-03 1.0E-02 1.0E-01 1.0E+00 1.0E+01 1.0E+02 1.0E+03
Pressure (Torr)
IGM402 Hornet
/ air only)
2
to 1,000 Torr as described below.
/air only)
2
Voltage
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
>10
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