The HCHO Sensor is a semiconductor VOC gas sensor. It is based on the WSP2110 where conductivity changes with the concentration of VOC gas in air. The conductivity is converted to an output signal that corresponds to the gas concentration. This sensor has a very high sensitivity and stability. It can detect the gas with concentration up to 1ppm. It’s suitable for detecting formaldehyde, benzene, toluene and other volatile components. This product can be used to detect harmful gas in the home environment. Therefore, it’s a good assistant for you to improve indoor environment quality of life.