Heated diode sensor brings upper precision compared to conventional sensors. Accurate Leak Detection; detects halogen refrigerant leaks down to 0.1 oz/yr with 3 sensitivity modes, It is compatible with a wide range of refrigerants, including HFCs(R134a, R410A, R404A, R507, R23, etc.); HCFCs(R22, R123, R124,etc); CFCs: (R12, R13, R502 etc.); PFCs(PFC-14, PFC-116, PFC-218 etc); HFO: R1234fy.