The Optimization of a Photoacoustic Refrigerant Sensor System Using a Three-Chamber Concept

Ever since the ban of the refrigerant R134a in 2017 for all newly manufactured vehicles, due to its high global warming potential, the necessity of low-cost, reliable and precise refrigerant measuring devices has arisen. We present a photoacoustic gas detector for the refrigerants R134a and the environmentally friendly alternative R1234yf. The sensor consists of a detection, an absorption and a filter chamber. The influence of the filter chamber length on the sensor signal was evaluated and a signal drift, originating from filter chamber leakage, was successfully eliminated and validated by FTIR measurements.