Ion Gauge Analog Output - Ig Only - Instrutech The Hornet IGM402 User Manual

Instruction Manual

Ion gauge analog output - IG ONLY

6.1
ANALOG MODE in SETUP IG menu is set to IG ONLY. LOG-LINEAR 0-9 Vdc, 1 V/decade (N
A) The log-linear output signal and pressure are related by the
following formulas when units of measurement is in Torr and
mbar:
(volts – 10)
P= 10 V= log
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 - 8)
P= 10 V= log
Where P is the pressure in pascals, and V is the output signal in
Volts.
Notes - The output voltage will switch to above +10 Vdc under
the following conditions:
1) The filament is turned off or any IG fault condition.
2) The pressure exceeds 1.00 x 10
3) The pressure exceeds 5.0 x 10
emission current.
The following chart shows the graphical results of table and formulas above for 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.
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
1.0E-10 1.0E-09 1.0E-08
InstruTech
(P) + 10
10
(P) + 8
10
-3
Torr at 4 mA emission current.
-2
Torr at 0.1 mA (100
Log-Linear Analog Voltage to Pressure
1.0E-07 1.0E-06 1.0E-05
Pressure (Torr)
Log-Linear Analog Output (N
Pressure (Torr)
See Notes
µ
A)
1.0E-04 1.0E-03 1.0E-02 1.0E-01
IGM402 Hornet
/ air only)
2
/air only)
2
Voltage
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
5.0E-02 8.698
>10 VDC
See the
conditions
listed above
which will
cause the
output to
switch to
>10VDC.
These
conditions
are listed
immediately
above this
chart on this
page.
1.0E+00
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
>10
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