To improve a measurement precision in the non-destructive measurement method of hydrogen concentration by an electromagnetic ultrasonic resonance method.
In the non-destructive measurement method, a magnet and a coil 13 are arranged near the surface of a member 11 to be measured. A magnetic flux density near the surface of the member to be measured is varied by giving a high-frequency current to a coil. Ultrasonic waves are generated from a part to be measured by a variation in the magnetic flux density. Ultrasonic vibration is received by an electromagnetic ultrasonic sensor. A frequency in a high-frequency current is changed to obtain a resonance frequency, and hydrogen concentration in the member to be measured is obtained based on the resonance frequency. Further, in the non-destructive measurement method, one coil is arranged so that the major axis of the coil does not coincide with the axial direction (for example extension direction) of the elastic characteristics of the member to be measured. Without changing the relative position relationship between the coil and the member to be measured, two resonance frequencies are obtained based on the deviation between the axial direction of elastic characteristics and the direction of the major axis. By using the two resonance frequencies (for example the difference), hydrogen concentration in the member to be measured is obtained.
NAKATSUKA MASAFUMI
ISHIMOTO SHINJI
GLOBAL NUCLEAR FUEL JP CO LTD
Osamu Kikuchi
Hiroko Inomata
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