Biogas analyzer include online, portable, handheld and wall mounted models adopt international advanced NDIR non-dispersed infrared technology and ECD long life electrochemical techniques. It is used to measure the volume concentration of CH4, CO2, H2S, O2 in biogas with high precision, smart structure, easy operation. It is extensively applied in landfill, sewage treatment, anaerobic fermentation, CDM measurement and other fields.