| 摘要 |
PURPOSE:To enable accurate measurement of the depth of penetration of a weld part at a bridge girder or the like by prescribing the range of obtaining a flaw detection data for the height of bottom surface echo. CONSTITUTION:First, from a plotter display of the height of a bottom surface echo at the scanning of a probe 5 in the direction X, the range DELTAX of obtaining data for the height HB of the bottom surface echo is determined to set and then, the probe 5 is moved in the direction X' to be set at the position of starting the scanning. Then, the probe 5 is scanned in the direction X. At this point, as the probe 5 enters the range of measuring the height HB of the echo, an automatic decider starts to take in the echo height HB to determine the position P1 at which the echo height reaching one half the maximum is generated among the echo heights HB obtained until the movement in the direction X stops. The range DELTAX is set somewhere between the penetration tip position P1 from which the echo height reaches the peak to the point P1' at which the echo height reaches one half the maximum thereof HBM after it lowers from the peak point. Therefore, the point at which the echo height reaches one half the maximum thereof is only P1 in the range DELTAX thereby eliminating the detection of any wrong position. |
