New measurements and a discussion of existing data

Abstract

The design of a transient hot-wire cell for measurements on liquids is described. The cell is incorporated in a high stability circuit and the temperature time function which yields the thermal conductivity logged by means of high-speed digital equipment. Ancillary equipment is developed to enable measurements to be made on liquids from 100 to 450 K and pressures to 100 bar (10 MPa). Results are reported on liquid toluene at saturation pressure over the whole of its normal liquid range. Comparison is made with selected data taking into account the effect of heat transfer by radiation. It is suggested that most of the data reviewed are accurate, regarded as apparatus conductivity, uncorrected for radiation, to rather better than 1 %, and that the present data, over most of the temperature range, are true conductivities of similar accuracy. However, several anomalous relations with existing data are noted.