620 Measurements of Thermal Expansion Coefficients of plates at Low Temperatures Using Electronic Speckle Pattern Interferometry

Abstract

The thermal expansion coefficient of rectangular specimens at low temperatures was measured by Electronic Speckle Pattern Interferometry(ESPI). Since ESPI is a non-contact measurement method, ESPI system doesn't receive the influence of temperature change. The thermal expansion coefficient was obtained from the thermal strain acquired by ESPI and the temperature measurement for specimens of Poly tetra fluoro ethylene(PTFE) and Stainless steel(SUS316). The thermal expansion coefficients of SUS316 and PTFE were obtained in the temperature range from 130K to 300K, 150K to 330, respectively. These data agree well with the published ones.