Measurement techniques

Abstract

The special problems of measurements on thermoelectric materials are mentioned. It is shown how errors associated with the thermoelectric effects can be avoided when measuring the electrical conductivity. The principles for reliable assessment of the Seebeck coefficient are emphasised. Accurate thermal conductivity measurements have always been difficult and the methods of minimising the errors are outlined. It is shown that the measurement of thermal diffusivity can help in the avoidance of errors due to heat transfer by radiation. Particular attention is paid to the direct measurement of the figure of merit. A description is given of apparatus for determining the thermomagnetic coefficients.