Abstract
A remarkable color change of some materials caused by a variation of temperature is called "thermochromism" and the materials having this property are "thermochromic materials". The purpose of the present study is to develop a measuring device of temperature by using thermochromic materials, other a liquid crystal. Relationships were obtained between temperatures and color changes, The first, we developed systems to test thermochromic materials which can measure light from the sample by using a spectrometer and their temperature change simultaneously. Then we examined three thermochromic materials which are phosphor, solution of metal complex, and chiral-nematic liquid crystal. From the spectra, it was found that each relative intensity varied characteristically with temperature change. Then we supposed some parameters which characterize color changes for each thermochromic material. It is found that there are strong correlations between temperature and all the selected parameters. Each thermochromic material shows a diffrerent and unique behavior on spectrum characteristics, although they can not be distinguished with naked eyes. Knowledge of spectrum characteristics for individual thermochromic materials makes it possible to develop a measuring device such as a TV camera with an image processor.
