Instrutech Wasp WGM701, User Manual

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Instruction Manual WGM701 Wasp
InstruTech
Page 18
6 Analog Output
The WGM701 provides a 0.5 to 7 Vdc, 0.5 V/decade log-linear signal proportional to pressure.
A) The log-linear output signal and pressure are related by the
following formulas when units of measurement is in
Torr and
mbar:
P = 10
(volts – 5.5)/(0.5)
V = ((0.5 X log
10
(P)) + 5.5
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:
P = 10
(volts - 4.5)/(0.5)
V = ((0.5 X log
10
(P)) + 4.5
Note: The output voltage is +10 Vdc when pressure is in the
cold cathode measurement but the cold cathode sensor has
not ignited.
Log-Linear Analog Output (N
2
/air only)
Pressure (Torr) Voltage
1.0E-09 1.0
1.0E-08 1.5
1.0E-07 2.0
1.0E-06 2.5
1.0E-05 3.0
1.0E-04 3.5
1.0E-03 4.0
1.0E-02 4.5
1.0E-01 5.0
1.0E+00 5.5
1.0E+01 6.0
1.0E+02 6.5
7.6E+02 6.94
See Note >10
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.
Log-Linear Analog Voltage to Pressure
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
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
Pressure (Torr)
Ou
tp
ut
Si
gn
al
(Vo
lts
dc)