Teledyne API M452 Ozone Sensor Instruction Manual, 02852, Rev. E
5-4
5.6 Cell Dirty The normal state for the Cell Dirty output is OFF. If this output turns on,
then the ratio of the measure detector to the reference detector (at zero) is
< 0.5. This value is calculated when the zero calibration is performed.
When this output is on, it indicates a loss of optical transmission through
the windows in the absorption cell or a calibration fault.
5.7 Status Output Summary Table Table 5-2 below is a logic truth table summarizing the recommended
actions based on the states of the four status outputs. A ‘1’ indicates the
output is ON, a ‘0’ indicates the output is OFF, and ‘X’ indicates the
output is in either state.
Table 5-2: Status Output Truth Table
Sensor
OK Invalid
Reading Lamp
Low Cell
Dirty Actions
1 0 0 0
Normal operation, no
action required
0 X X X Service required
1 1 X X
Check Pressure > 45 psia
Verify that concentration
has not exceeded full scale
range of sensor.
Calibrate at Zero.
1 X 1 X
Lamp adjustment useful,
though not required
1 X X 1
Calibrate at zero
Clean Cell