Carbon monoxide sensor module

Model: MQ-9.
Carbon monoxide sensor module.
Mainly used to detect gases like carbon monoxide, methane, and propane, etc. This sensor contains a sensing element, mainly aluminum-oxide based ceramic, coated with Tin dioxide (SnO2), enclosed in a stainless steel mesh. Whenever gas comes into contact with the sensing element, the resistivity of the element changes. The change is then measured to get the concentration of the gases present. It has a small heating element present which is needed to preheat the sensor to get it in the working window. It can detect LPG, propane, hydrogen, carbon monoxide, and methane cas concentrations. It finds uses in detecting gas leakage in pipelines, Alarm application in case of a gas leak at home as CO is a very harmful gas and can kill a person if present over 300 PPM.