METHOD FOR MEASURING TEMPERATURE

PURPOSE: To measure temperature of an object to be inspected by detecting only either fluorescence of a detection band contained in the fluorescence and applying it to a distribution function at the time when the band of a chemical species NO is excited as a specific chemical species and the temperature is measured from the distribution function of each rotation line. CONSTITUTION: A beam expander 7 for making laser light 6 from a laser 5 sheetlike, a cylindrical lens 8, and a biprism 9 are equipped. The laser light 6 transmitting through a flame 2 is received on a beam stopper 10. Fluorescence 11 is detected by a CCD camera 15 with an image intensifier 14 through an imaging lens 12 and a filter 13, and the image-formation is stored to a flame memory 16. The band A2 Σ -X2 II (0, 0) of a chemical species NO in the flame is excited, and only either fluorescence of the band of (0, 1)-(0, 4) is detected. Selection is determined by the filter 13. Temperature is found by a distribution calculating means 17 for storing a distribution function of each rotation line and a temperature calculating means 18 for calculating the temperature of an object to be inspected by the distribution function.