Abstract
After completing the first report, the authors made comparative study of radiographic examinations by X-Ray and GAMMA-Ray in respect of range utilization, advantage and disadvantage and nrotection from radiation, and the results obtained are as follows:
1. Inspection by the 1, 000 KV X-Ray can be applied only to objects which can be carried into the specified inspection-room. Such inspection is available not only for steel plates of thickness 5"-6" but for various castings which differ in thickness.
It must be noted, howevrer, that the films for such inspection must be imported ones for the time being.
2. The portable 150 KV X-Ray, which is available for inspection of steel plate up to 1.6 inches in thickness, can be used for examination of welded parts at any site of work desired.
3. It is recommended that where the 1000 KV X-Ray and 150 KV X-Ray (portable).can ribt be annlied. GAMMA-Ray of Isotope (Co60) is to be used, for instance, pipe welding parts and the like.
It shuld be a concern of great import that as it is very difficult to provide proper protection against the radiation of the GAMMA-Ray, special care must be taken in order to minimize the undesirable effect by keeping at a proper distance from the source of radiation or making the time of exposure to radiation as short as possible.
