TEMPERATURE MEASURING DEVICE

PURPOSE:To simplify the constitution of a temperature measuring device, by counting clock pulses during the period, in which the afterglow output of a temperature dependent fluorescent body exceeds a specified level. CONSTITUTION:A temperature dependent afterglow signal from a fluorescent body 2 is converted into an electric signal by a light receiving device 4 through an optical fiber 1, a half mirror 11, and the like. When the level of the signal exceeds a specified value, the output of a comparator 6 forming a level discriminator becomes a high level, an AND gate 7, through which clock pulses from an oscillator 8 passes, is opened, the clock pulses are counted by a counter (a) of a CPU 10, and a temperature is measured. Therefore, an A/D converter and the like are not required, signal processing becomes easy, and the constitution of the temperature measuring device utilizing the afterglow characteristics is simplified.