Font-size:bigger smaller reset You are here: Home Products SES ASA - F&G Detection Field Devices GAS Fixed Point Toxic Electrochemical Main Menu Home Products SES ASA - F&G Detection Field Devices GAS Fixed Point Combustible Toxic Electrochemical SMART S500 MT-TX Metal Oxide Oxygen Open Path Flame Controllers SES ENSER - Extinguishing System Integration Quality & Innovation Company HSE Policy Knowledge base References More about US Electrochemical Gas Detection Electrochemical gas sensors are gas detectors that measure the volume of a target gas by oxidizing or reducing the target gas at an electrode and measuring the resulting current. The gas diffuses into the sensor, through the back of the membrane to the working electrode where it is oxidized or reduced. This electrochemical reaction results in an electric current that passes through the transmitter circuit. In addition to measuring, amplifying and performing and signal processing functions, the transmitter circuit maintains the voltage across the sensor between the working and counter electrodes for a two electrode sensor or between the working and reference electrodes for a three electrode cell. At the counter electrode an equal and opposite reaction occurs, such that if the working electrode is an oxidation, then the counter electrode is a reduction. The magnitude of the current is controlled by how much of the target gas is oxidized at the working electrode.This linear output is one of the advantages of electrochemical sensors over other sensor technologies, (e.g. infrared), whose output must be linearized before they can be used. A linear output allows for more precise measurement of low concentrations and much simpler calibration.