To measure accurately the surface temperature of a measuring object by using an infrared camera from a position isolated by a transmission medium capable of transmitting a prescribed wavelength.
In this method, the surface temperature of the measuring object is measured by using the infrared camera 12 from the position where the measuring object and the atmosphere of the periphery of the measuring object are isolated by a window 1a capable of transmitting the prescribed wavelength. Between the infrared camera 12 and the window 1a, a glass 14 capable of preventing transmission of an unnecessary wave range by being combined with the window 1a or by either of them is installed, and measurement is performed, while the window 1a and the glass 14 are cooled so as to keep the temperature at which a measuring error determined beforehand is in a tolerance. Therefore, when measuring the surface temperature of the measuring object through the transmission medium capable of transmitting the prescribed wavelength, a noise generated in the unnecessary wave range is reduced, to thereby improve the measurement accuracy.
ITO KEIJI
TERADA YUKIHIRO
