METHOD AND DEVICE FOR MEASURING COATING THICKNESS BY ULTRASONIC WAVE

Japanese Patent JP3510137

B2

PROBLEM TO BE SOLVED: To accurately measure a coating thickness by using a test piece whose front and reverse sides are smooth for obtaining the reflection wave rising direction of a probe, at the same time obtaining the maximum echo height of the reflection wave of a measurement target, and setting a threshold to a direction that is opposite to the reflection wave rising direction.
SOLUTION: A test piece with smooth front and reverse surfaces and a small internal attenuation rate is used, the reflection wave rising direction of an ultrasonic probe 2 is obtained, and at the same time the reflection time of a bottom surface reflection wave and a voltage value corresponding to it are measured by a measurement part 5 and are stored in a storage part 7. Also, the maximum echo of the reflection wave of the measurement target is obtained by the ultrasonic probe 2. An operation part 6 sets a threshold to a direction that is opposite to the reflection wave rising direction for the reflection wave based on the maximum echo height, obtains time for indicating the maximum value in the waveform of the reflection wave exceeding the threshold for the first time, and sets time before the time by 3/4 periods as reflection wave reception time. Then, distance is obtained from the measured reflection time, bottom surface reflection time stored in the storage part 7, and the sound speed value of the measurement target to calculate the value of coating thickness.

Watase, Naoki
Takahashi, Kenichi
Tominaga, Tetsuya
Yamaguchi, Toshiyuki

JP5606399A

March 22, 2004

March 03, 1999

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HITACHI TECHNO ENG CO LTD

G01B17/02; (IPC1-7): G01B17/02

高田 幸彦 （外１名）

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