PURPOSE: To obtain a title device which can obtain exact measurement results of only radioactivity deposited on a body surface without previous measurement of radioactivity from inside a body.
CONSTITUTION: A thin-type β-ray detector 12 is fitted with a γ-ray detector 16 on the back side to constitute the principal part. On the basis of a count value of the whole γ rays of the γ-ray detector 16, a γ-ray count value (count of a part of γ-rays) by the β-ray detector 12 is calculated by a first arithmetic part 26. A calculated value of the first arithmetic part 26 is subtracted from a count value of the β-ray detector 12 by a second arithmetic part 28 so as to obtain measurements only of β rays due to radioactivity detected on the body surface of a subject 100.
MATSUBARA SHOHEI
OSHIMA TOSHINORI
