| 摘要 |
PROBLEM TO BE SOLVED: To more accurately grasp the properties and size of a flaw by calculating the position and size of the flaw from the elapse time from the point of time of the incidence of the ultrasonic echo returned to an ultrasonic probe from an ultrasonic transmission position and the interior of an object to be inspected after ultrasonic waves are incident on the object to be inspected. SOLUTION: Oblique angle probes 1a, 1b transmitting ultrasonic waves 2 to a steel panel 5 at an incident angle θ and arranged so as to be separated from each other by 2dtanθ so as to be capable of receiving a bottom surface echo and the connection means 3 of them are provided. Flaw detectors 10a, 10b applying pulse voltage to the probes 1a, 1b to amplify the signals from the probes, gate circuits. 13a, 13b receiving the amplified signals and A/D boards 17a, 17b consisting of A/D converters 16a, 16b and memories 15a, 15b are provided and the gates of the circuits 13a, 13b are adjusted. |
