Abstract
Accurate measurement of temperature is very important for monitoring or controlling the production process. Development of radiation thermometers has been remarkable in recent years. However, to measure accurate temperature, the infrared radiation thermometry have to calibrate emissivities of objects. Without calibration of emissivities, serious error is appears. This error can be reduced, if radiation of shorter wavelength, such as the Ultra-Violet range, is observed. UV radiation thermometry can measure temperature distributions of the stainless steel TIG weld pool accurately without correcting the emissivity.