Temperature measurements using a projection to latent structures of fluorescence spectra of potassium–aluminum borate glasses with copper-containing molecular clusters

Luminescence spectra of a potassium–aluminum borate glass with copper-containing molecular clusters are presented in the temperature range of 295–624 K. Two methods of temperature measurement are compared with the aim of evaluating the possibility of their further application in optical temperature sensors: specifically, the classical method of measuring a temperature based on the spectral position of the fluorescence band peak and the measurement method based on projection to latent structures of fluorescence spectra in the visible range. It is shown that, concerning the accuracy of measuring a temperature, the fourdimensional space of latent structures is preferred for the case under consideration; it allows one to determine (using a training set of fluorescence spectra) a temperature with the relative error of no more than 1.2%.