| 摘要 |
PURPOSE:To make it possible to inspect the cross-sectional area of a coated welding rod in detailed in a non-destructive manner, by dividing each picture element constituting a tomographic image according to the transmission quantity of radioactive rays and calculating the total number of picture elements at every division while calculating the ratio thereof to all picture elements. CONSTITUTION:A radiation beam irradiation apparatus 3 and a radiation detector 4 are set and integrally moved from scanning start points 7, 7 along a scanning line 6 while irradiating radiation beam 5 and the quantity of radiation beam transmitted through a coated welding rod 1 is detected. When the first time scanning of the cross-sectional area 2 of said welding rod is finished, a pair of the radiation beam irradiation apparatus 3 and the radiation detector 4 are rotated to again detect the quantity of transmitted radiation beam and this operation is repeated to obtain a reverse projection image. This image is put in an image analyzer and the transmission quantity of radiation beam at every picture element is divided into, for example, 16 stage levels to calculate the number of respective picture elements and the ratio with the total number of picture elements is calculated to inspect the cross-sectional area of the coated welding rod. |
