... principle analyze the CH4 and CO2 BX569A Portable biogas Detectors with pump BX569A portable biogas Detectors with pump, adopting NDIR detecting principle ... , is used to analyze the CH4 and CO2 during the biogas processing. At the same, with external PH sensor, it can ... also analyze the PH level of the biogas fluid. By combining tip detecting technology and simple operation, this ...