Calibration and Troubleshooting of Oxygen Analyzer

Calibration of Oxygen Analyzer

Calibration of most types of oxygen analyzers can be performed manually or by an automatic calibration option. The analyzer controller can be programmed to perform the automatic calibration at specific time intervals, review the calibration results and if they are within programmable parameters, update the controller with the new calibration data.

The procedures are the same for manual or automatic calibrations with the exception that in manual mode, the calibration data has to be manually accepted after the calibration runs.

The calibration procedure is very similar to each type of analyzer, therefore, it is recommended to following the manufacturer’s procedure. The calibration procedures are typically programmer orientated and involve two calibrations gases with the results adjusting the slope of the calibration line within the software.

To Calibrate

*Zero and span gases are connected to the analyzer.

*With the zero-gas flowing through the analyzer, allow the readings to stabilize, then correct the reading to equal the zero gas concentration.

*With the span-gas flowing through the analyzer, allow the readings to stabilize, then correct the reading to equal the span gas concentration.

Troubleshooting of Oxygen Analyzer

Faults with the oxygen analyzer output can be generated from several courses:

Sampling System

The sampling system should be periodically checked for proper flows and pressures and filtration and moisture removal.

Low readings are an indication of improper sampling.

Sensor

Zirconia Cell

The inaccurate readings could result from:

Heater temperature thermocouples

Heater itself

Heater temperature controller

Contaminated electrodes

Contaminated zirconia cell

All items should be checked according to the manufacturer’s procedures and diagnostics

Thermoparamagnetic

The inaccurate readings could result from:

Thermistors

Electronic sensing circuit

Auto-zero function

Changing magnetic field

All items should be checked according to the manufacturer’s procedures and diagnostics

Glass Sphere Paramagnetic

The inaccurate readings could result from:

Electronic sensing circuit

Light emitter

Photodiodes

Changing magnetic field

All items should be checked according to the manufacturer’s procedures and diagnostics

Electronics

All analyzers are equipped with extensive self-diagnostics and troubleshooting guides by the manufacturer, which should be followed for any alarms or inaccurate readings.

Author: Mohammed Khaleel

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