Hydrofluoroolefins Leakage Detection by Nondispersive Infrared Gas Sensor Using InAsSb Light Emitting Diodes and Photodiodes

Increasing concerns on global warming has been causing the shift of refrigerant from hydrofluorocarbons to natural refrigerants and hydrofluoroolefins, because of their very low global warming potential. We have fabricated nondispersive infrared gas sensing module for refrigerant R-1234yf, which is a possible substitute for refrigerant in automotive air conditioning systems. Signal response of up to 5000 ppm was observed with 60 ppm resolution (1 sigma). Unlike semiconductor type sensors, humidity had negligible impact on measurement capability. In order to achieve a low power operation, we have utilized light emitting diode and photodiode working in long wavelength infrared range, which have led to an extremely low current consumption of 150 mu A.