Miniaturized photoacoustic detection of organofluorine-based refrigerants

Abstract

Due to the ban on hydrofluorocarbon and haloalkane refrigerants with a high global warming potential, such as R134a, in the automotive industry, the significance of reliable and precise measuring devices for these refrigerants has risen. We present a photoacoustic gas detector for monitoring the organofluorine-based refrigerants R134a and R1234yf. The idea for this sensor is based on the three-chamber concept (a detection chamber, absorption chamber, and filter chamber). The optimal parameters and dimensions of the photoacoustic sensor components were determined via simulations. The simulation results were the cornerstone of our hardware construction. The first measurements with the newly developed sensor showed a sufficient signal-to-noise ratio for a reliable 0.5 vol. % (0.005 m3 m−3) detection resolution. The influence and importance of the filter chamber were examined and validated.