Abstract
This paper presents a method of reconstructing the temperature distributions of water around a small heated sphere. This method is based on the temperature dependence of the absorbance of water at the wavelength of 975 nm. Absorbance images at this wavelength were obtained when an iron sphere with a diameter of 1 mm located in water contained in a glass cell with a light path length of 10 mm was heated by a high-frequency magnetic field. Inverse Abel transform was applied to the line profiles of the absorbance, and cross-sectional temperature distributions around the sphere were reconstructed. The temperature distributions vary with the magnitudes of the magnetic field, which indicates the possibility of quantitative evaluation of induction heating systems.