Geothermal power generation is a method of generating electricity using steam from underground hot springs. Compounds in this hot spring water, such as silicon dioxide and sulfur, accumulate on the inner walls of steel pipes at geothermal power plants, forming a layer referred to as hot spring scale. This deposition can clog the pipes in geothermal power plants. Therefore, determining the thickness of the hot spring scale deposited on the inside of steel pipes from the outside of the pipe is crucial. In this study, an inspection method is proposed to measure the thickness of hot spring scale inside a steel pipe using vibration induced by electromagnetic force. The proposed method was applied to steel pipes used in an actual geothermal power plant, demonstrating the usefulness of the approach.
Ikusada et al. (2026) studied this question.