Gasboard 8500D ultrasonic oxygen sensor is an economical gas sensor used to detect oxygen concentration in binary gases. By adopting ultrasonic detecting technology, it is very stable and there is no need to calibrate the sensor in the application. It is mainly designed for ventilator oxygen concentration measurement with high flow range up to 80L and for the large PSA generator too.Compared with electro-chemical oxygen sensors, it has a much longer lifespan and a more stable performance.