Types of Gas Detectors: (1) Electrochemical Detectors: Electrochemical gas detectors work by allowing gases to diffuse through a porous membrane to an electrode where it is either oxidized or reduced. The amount of current produced is determined by how much of the gas is oxidized at the electrode. The sensor is then able to determine the concentration of the gas. Manufactures can customize electrochemical gas detectors by changing the porous barrier to allow for the detection of a certain gas concentration range. Also, since the diffusion barrier is a physical/mechanical barrier, the detector tends to be more stable and reliable over the sensor's duration and thus requires less maintenance than other types of detectors. However, the sensors themselves are subject to corrosive elements and may last only 1-2 years before a replacement is required. Electrochemical gas detectors are used in a wide variety of environments such as refineries, gas turbines, chemical plants, underground gas storage facilities, and more