Patent ID: 7534031

Claim:
A temperature measuring device, comprising: a light source for outputting light; an optical fiber to which light outputted by said light source is inputted, and from which Brillouin scattered light is outputted from said optical fiber in response to said light input; detection means for detecting a spectrum of said Brillouin scattered light outputted from said optical fiber; judgment means for judging whether or not a frequency shift of the spectrum of said Brillouin scattered light detected by said detection means belongs to a specific region in which the rate of change of the frequency shift with respect to the temperature of said optical fiber is smaller than a predetermined value; and analysis means for, when said judgment means judges that said frequency shift does not belong to said specific region, analyzing said temperature in use of said frequency shift, and for, when said judgment means judges that said frequency shift belongs to said specific region, not performing analysis, or analyzing said temperature in use of at least a linewidth of the spectrum of the Brillouin scattered light detected by said detection means.