Uniweld's Propane Halide Leak Detector instantly locates non-combustible halide (CFC and HCFC) refrigerant gas leaks. Leaks are located when the chlorine based refrigerant gases are drawn in through the probe hose and exposed to a heated copper reactor plate, changing the blue flame to green. This detector is very sensitive and can be used to locate leaks as small as 20 ppm of CFC and HCFC refrigerants. Will not detect non-chlorine based refrigerants (such as R-410A).