[en] A world-wide movement is growing for the protection of living bodies against leakage radiations. In Japan, detailed regulations have been established for the enforcement of the law in regard to this problem. The substances of the measurement provided in the regulations are extremely diversified, much affecting the reliability and the economic efficiency of the equipment. Now a new 4π-scan X-ray dosimeter with high reliability has been developed and proved to effect qualitative improvement of measurement as well as elevation of productivity. (auth.)