Kurt J. Lesker 979 Series, Operation And Maintenance Manual

Page: 37 / 54

Series 979 ATV Transducer 37
The 979 ATV Transducer analog voltage signal pins are 5 (+) and 6 (-).
Connect them to a differential input. The transducer provides 2 analog output
scales: DAC1 is 0.5V/decade; DAC2 is 0.774V to 10V.
Do not connect the negative side of the analog output (pin 6) to
the power supply return (pin 4) or to any other ground. The
voltage drop from the supply current will produce errors in the
analog output voltage. The longer the cable, the worse the error
will be.
The graph below shows the correlation of DAC1 analog output to pressure.
To calculate pressure from voltage: P (Torr) = 10
(2V-11)
Analog Output
DAC1 Voltage vs Pressure
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
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, mBar or Pascal/100
Vo
lt
s
Torr or mBar Pascal