An electrochemical or EC sensor measures the concentration of gas by oxidizing or reducing the gas and the electrode is used to measure the resulting electrical current output. These types of sensors are used for detecting oxygen and toxic gases.
A catalytic, Cat EX or combustible sensor oxidizes a combustible gas and converts the temperatures change into an electrical signal. These types of sensors are used for detecting combustible gases, such as methane, propane and hydrogen.
An infrared or IR sensor measures trace gases by determining the absorption of an emitted infrared light source through an air sample. These types of sensors are used for detecting carbon dioxide and a wide range of combustible gases.
A photo-ionization detector or PID breaks molecules into positive and negative charged ions and measures the electrical charge of these ions using a detector to display the amount of gas or vapour that is present. These types of sensors are used for detecting volatile organic vapors (VOCs) and toxic gases.