A thermoelastic method for the measurement of thermal expansion coefficient of solids

A measurement method for the thermal expansion coefficient of elastic solid s has been developed. The method exploits the thermoelastic effect, the dua l effect of thermal expansion: it is based on elastic compression of a smal l cylindrical specimen by a simple accessory for a conventional material te sting machine whose applications are extended to the measurement of thermop hysical properties. Compression induces a temperature variation proportiona l to the ratio of thermal expansion coefficient to specific heat; the expan sion coefficient is then derived by an independent measurement of specific heat. Temperature can be measured in both quasiadiabatic and nonadiabatic c onditions, and also allows in situ characterization of the temperature sens or promptness. Precision and accuracy of the measured ratio have been asses sed by Certified Reference Materials: they are comparable to those of other methods. (C) 2000 American Institute of Physics. [S0034-6748(00)00601-8].