| 摘要 |
PURPOSE:To obtain a clear image, by changing the slice level with respect to an echo signal detected corresponding to the flaw detection depth to reduce effect of noise echoes satisfactorily. CONSTITUTION:An ultrasonic wave outputted from a vibrator 32 is made incident into carbon steel, stainless steel and other material to be detected and reflected echoes are incident into the vibrator 32 from the surface, defects or the bottom surface thereof. These signals correspond to the image of an A scope and integrated in multiplicity to form an image of a B scope. As the slice level changes corresponding to the depthl of material to be detected, noise echoes can be cancelled regardless of any DAC and signals of a memory 44 are selected with a select circuit 46D, eliminating changes in the echo height. As the slice level increases gradually corresponding to the depth l, the expanse of the sound field can be supressed eventually to obtain a sharp signal even with respect to the reflected echo with a greater depth l. This can get rid of noise echoes thereby inhibiting degrading of the image due to noise echoes. |
