... dispersive infrared (NDIR) technology to determine the weight concentrations of R12, R134a, R22, hydrocarbons and air."Blend-ID" analytical software ... and butane.Quickly and automatically determines if the purity of R12 and R134a refrigerant is at industry acceptable levels. Specifications ... : Digital display and LEDs, Optional printer module (Internal)Refrigerant : R12, R134a, R22, HC, and EPA S.N.A.P. ...