Teledyne 3020M - Explosion proof paramagnetic oxygen analyzer - Manual (Page 16)

2-2
2 Operational Theory Model 3020M
Teledyne Analytical Instruments
bell to the zero position in the presence of zero gas (i.e. no O
2
present) or of
sample gas is proportional to the partial pressure of oxygen in the sample
gas.
The sensor enclosure is temperature controlled to 55 degrees centigrade
to insure that the magnetic susceptibility of oxygen in the sample is not
affected by the ambient temperature. The measuring cell has a measuring
volume of approximately 3 cm
3
Sensor
(side view shown)
The Paramagnetic sensor enclosure holds not only the sensing elements,
but the temperature controller electronics, heating elements, sensor electron-
ics, and preamplifier. The Electronics and heating elements require a separate
power source, from the rest of the 3020M capable of delivering 1.5 amps
approximately at 24 volts dc. The output of the sensor is roughly calibrated
to be 0 to 1 volt DC for the the range of 0 to 100 % 02. The true calibration
of the sensor is carried out by the microprocessor as described later in chap-
ter 4. The electrical interconnections to the sensor are done through a 15 pin
D connector. Some signals from the sensor are not connected. They are only
useful for troubleshooting, by trained personnel, as test points.