Linear expansion coefficient measuring device and linear expansion coefficient measurement method

摘要

PROBLEM TO BE SOLVED: To reduce a burden of measuring work and simplify an apparatus in a linear expansion coefficient measuring apparatus and a linear expansion coefficient measuring method for finding a linear expansion coefficient of a sample from a change of light path lengths of reflected lights from two reflection plates for sandwiching the sample.;SOLUTION: The linear expansion coefficient measuring apparatus is provided with two reflection plates 11, 12 for sandwiching the sample 20, an accommodating tank 30 for accommodating them and filled with a gas having a known refraction index change, a temperature regulating means 40 for variably setting a temperature within the accommodating tank 30, a light source 71 for irradiating reflection faces 11a, 12a of the reflection plates 11, 12 with an irradiation light, a light receiving element 14 for receiving interfered reflection lights and detecting optical power, and a calculating means 60 for calculating the linear expansion coefficient of the sample. The calculating means 60 calculates the change of the light path lengths between the reflection plates 11a, 12a from an output change of the light receiving element 14 due to a temperature change within the accommodating tank 30, corrects the change of the light path lengths corresponding to the refraction index change of the gas within the accommodating tank 30 due to the temperature change, and calculates an expanding and contracting length of the sample 20.;COPYRIGHT: (C)2005,JPO&NCIPI