| 摘要 |
PURPOSE:To measure non-destructively and very quickly a moisture absorption degree by measuring an acoustic velocity of an ultrasonic wave with regard to an insulator to be measured, and deriving an absorption coefficient from a relation of the acoustic velocity of the ultrasonic wave and the absorption coefficient. CONSTITUTION:Many standard samples whose burning temperature is different from each other are made by the same material as an insulator to be measured, first of all, and with regard to each standard sample, an absorption coefficient is derived by a moisture absorption testing method based on JIS. Thereafter, an acoustic velocity of an ultrasonic wave propagated in each sample is derived, and a relation curve of said acoustic velocity and the absorption coefficient is derived. When measuring an insulator to be measured 10, a detecting end 14 of an ultrasonic thickness gauge 12 is made to abut onto a suitable part of the insulator to be measured 10 and an ultrasonic wave is irradiated, its response time is measured, and also a thickness of the abutting part is measured. Subsequently, the acoustic velocity of the ultrasonic wave is calculated from a measured value of the thickness and the response time, and the corresponding absorption coefficient is derived from the prepared relation curve. |
