Seeed Grove Range of Sensors and Modules - Seeed Studio 101020001, Seeed 101020001 Grove - HCHO Sensor is a semiconductor VOC gas sensor. It uses the VOC sensor WSP2110 whose conductivity changes with the concentration of VOC gas in the air. With a circuit, the conductivity can be converted to an output signal that corresponds to the gas concentration. This sensor has very high sensitivity and stability, that can detect gas whose concentration is up to 1ppm. It can be used to detect Toluene, Methanal, Benzene, Alcohol, Acetone and can detect the presence of harmful gas in the home environment, which makes it a good assistant to improve indoor air quality. Seeed 101020001 Grove - HCHO Sensor