CALIBRATING METHOD FOR RADIATION INSTRUMENTATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To obtain a radiation instrumentation system calibrating method which facilitates calibration by decreasing the number of movement points of a ray source. SOLUTION: A radiation detector 4 is installed at a position outside and below an object container to be measured nearly in a rectangular parallelepiped shape at a measurement-state position and a radiation source 6 is moved to a plurality of positions in one horizontal plane in the object container to be measured to find a sensitivity distribution in the horizontal plane from indication values of the radiation detectors; and a perpendicular sensitivity distribution is found as relative values by a radiation detector different from the mentioned radiation detector. Here, it is assumed that the sensitivity distribution in the horizontal plane in the object container is similar at respective height positions and three-dimensional detection efficiency (indication value/radiation dose rate) is found from the position and intensity of the ray source according to the sensitivity distribution in the horizontal plane and the perpendicular sensitivity distribution.