MKS Stabil-Ion 370 Series, Инструкция по эксплуатации, Страница: 88 / 122

4 Preparing the Stabil-Ion System for Operation
4-30
Series 370 Stabil-Ion Instruction Manual - 370119
4.10 Convectron Gauge Analog Output Signal
If the Convectron Gauge capability is installed, a voltage output
signal proportional to the common logarithm of the pressure
indication is provided on the rear panel of the Convectron Gauge
module via a standard 1/8 in. miniature phone jack.
If graphed on log-linear axes, the output voltage is linear with respect
to the log of pressure. The analog output is 1 volt per decade of
pressure with a factory adjusted output of 0 volts at 1.0 x 10
-4
Torr.
Offset adjustments are provided on the top edge of the Convectron
Gauge module that allow shifting the voltage corresponding to 1 x
10
-4
Torr between -7 volts and +1 volt.
The voltage signal is smooth and continuous throughout all the decades of pressure measurement.
This format is useful for computerized data acquisition because a simple equation (finding the
common antilogarithm) may be programmed to calculate pressure from the voltage output.
The equation is: P
i
= 10
V-4
Torr/mbar, or P
i
= 10
V-2
Pascal
Figure 4-17 Top View of Convectron
Gauge Module Showing
Analog Output Offset
Adjustment
Figure 4-18 Convectron Gauge Analog Output vs. Pressure
where Pi = pressure indication,
V = analog output voltage
Gauge analog output (V)
-7 -6 -5 3 4 5 6 7 8 9 10
1
10
10
3
10
2
10
-4
10
-3
10
-2
10
-1
10
2
10
5
10
4
10
3
10
-2
10
-1
1
10
lower adjust limit
factory adjustment
2 1 0 -1 -2 -3 -4
upper adjust limit
CONVECTRON
Pressur
e (Torr)
Pressur
e (Pa)