TEMPERATURE MEASURING APPARATUS

摘要

This invention relates to a temperature measuring apparatus which utilizes photoelasticity of a transparent material. The present invention uses, as a temperature-sensitive element, a temperature-stress convertor comprising a photoelastic element and a force application means which is disposed in close contact with the photoelastic element to cause it to generate stress with anisotropy in proportion to an ambient temperature using the difference in thermal expansion between the force application means and the photoelastic element. There is disposed a means for passing linear polarized light through the photoelastic element of the temperature-stress convertor and for detecting the phase difference between a polarized wave component of the transmitted light in one stress direction of the photoelastic element and a polarized wave component in a direction crossing the former at right angles. The detected phase difference is converted into a temperature and displayed on a display.