Abstract: Method and apparatus for measuring conductivity of test materials at a measurement temperature and displaying material conductivity at standard temperature by compensating the measured conductivity for conductivity changes due to the measurement-standard temperature differential. This is accomplished by developing a first periodic signal having a period which varies as a direct linear function of material conductivity C.sub.T at the measurement temperature, and a second periodic signal having a period which varies as a function of the product of measured conductivity C.sub.T, the measurement/standard temperature differential .DELTA.T and a conductivity constant .beta. characteristic of non-ferrous metals having a given base metal. Standard conductivity C.sub.S is then determined in accordance with the equation C.sub.S =C.sub.T (1 +.beta.C.sub.T .DELTA.T) as a combined function of the periods of the first and second signals, and is displayed in percent IACS at 20.degree. C.