Fluorescent Optical Oxygen Sensor Is A Breath of Fresh Air in the Oxygen Sensing Industry

Electrochemical sensors are sensitive to temperature and therefore require external compensation, using hardware or software methods. LuminOx from SST Sensing (UK) contains built-in temperature compensation so removes this requirement. Not only does LuminOx measure the temperature, but it’s two-wire communications port allows the gas temperature to be measured along with oxygen by the host – an added bonus!

The graphs show how LuminOx’s output remains constant while the gas temperature is changing. Electrochemical sensors, tested at the same time, exhibit significant errors as a result of the changing temperature.

The three sensors were supplied with various fixed gas concentrations and the temperature was varied between -20 and +50oC.

LuminOx clearly has significantly less sensitivity to temperature when compared to electrochemical sensors.

Electrochemical sensors are also susceptible to rapid changes in temperature. Again, LuminOx is less sensitive to this effect due to its built-in temperature compensation.

The three sensors were supplied with 21% O2 and the gas temperature was changed as rapidly as possible, using a heat exchanger, between 15 and 40 degrees C. The blue line in the graph is the gas temperature measured inside the test enclosure. The temperature is read on the axis to the right of the graph. The O2% reported by the three sensors is measured on the left axis.

Although all the sensors have some sensitivity to temperature changes, LuminOx is significantly less sensitive to the changes.