Apparatus for identifying and distinguishing different refrigerants

Abstract

Apparatus for identifying and distinguishing between at least two types of refrigerant that includes a fixed volume for containing a refrigerant sample at controlled vapor pressure. A thermistor provides a first electrical signal as a function of the combined effect of thermal conductivity and temperature of a refrigerant sample in the sample-containing volume, and a temperature sensor provides a second electrical signal as a function of temperature of the refrigerant vapor in the sample-containing volume essentially independent of thermal conductivity thereof. Associated electronics determines type of refrigerant in the sample-containing volume as a function of the first and second electrical signals, and thus as a function of thermal conductivity of the refrigerant sample independent of sample temperature. Since thermal conductivity of refrigerants at a given temperature and pressure varies for different refrigerant types, refrigerant type can be determined and displayed to an operator.

Dependencies are inferred from the claim text.