What is the difference between infrared and electrochemical gas sensors?
The main difference is in the measurement method. In electrochemical sensors, the sensitive element remains in direct contact with the gas and a chemical reaction occurs. This causes the sensor element to be contaminated by the reaction products which leads to loss of sensitivity, accuracy and calibration (drift). Most electrochemical sensors also are not very gas-specific. The infrared gas sensor, on the other hand, operates by measuring how much infrared light passing through a volume of gas is absorbed by the gas molecules, the gas being separated from the sensor components by IR-transparent windows. Moreover, infrared does this very specifically for each kind of molecular gas.
