| 摘要 |
PURPOSE:To perform tomography at cross-section within a steel pipe in sequence and enable the non-destructive inspection in detail, by a method wherein a radiation beam is irradiated into the steel pipe at diameter direction from every angle, distribution of radiation intensity obtained by a detector is processed at a central processing processing unit, and images are synthesized and outputted to an image reproducing device. CONSTITUTION:In order to obtain a tomographic image regarding a cross-section 2 of a steel pipe 1, a radiation source 4 and a detector 7 are aligned so that a radiation beam 6 passes through the cross-section 2 of the steel pipe 1, and both the radiation source 4 and the detector 7 are rotated integrally about the steel pipe 1 in direction A. The rotation ranges 180- 360 degrees, and the radiation beam 6 irradiated from the radiation source 4 during the rotation penetrates the steel pipe 1 and is detected by the detector 7 continuously in every angle. The radiation ray irradiated from a slit 5 is detected by another detector (GM counter) 8 in the direction different from that of the steel pipe 1, thereby penetrability (including absorption factor) of the radiation ray is determined. Detection values (a), (b) of the radiation are entered through an amplifier 9 and A-D converter 10 into a buffer memory 11 of a central processing unit (CPU)12. Intensity stored in the memory 11 is processed in the CPU12 so that it is projected reversely to the cross-section 2 and then displayed in a CRT17. |
