Technique: It adopts infrared technique to detect instead of high/temperature relationship. Identificaiton of refrigerant: It could identify whether the refrigerant is R12 or R134A while the purity reaches 98%. Application: R12 or R134A. Alarm：It has Hydrocarbon content exceeding warning function. It would alarm when it detects the Hydrocarbon content exceeding in refrigerant. Identification air content: It also has the identification function of air content. Power Supply:12V DC.