Sensitive material of MQ138 gas sensor is SnO2, which with lower conductivity in clean air. When VOC gas exists, the sensor’s conductivity gets higher along with the gas concentration rising. Users can convert the change of conductivity to correspond output signal of gas concentration through a simple circuit.
MQ138 gas sensor has high sensitivity to toluene, acetone, alcohol, methanol, also can monitor hydrogen and other organic vapour well. It can detect kinds of organic gases and is a kind of low-cost sensor for kinds of applications.
Application
It is widely used in domestic VOC gas alarm, industrial VOC gas leakage alarm and portable VOC gas detector.
Features
It has good sensitivity to organic vapour gas in wide range, and has advantages such as long lifespan, low cost and simple drive circuit &etc.