| 摘要 |
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 beta-ray detector 12 is fitted with a gamma-ray detector 16 on the back side to constitute the principal part. On the basis of a count value of the whole gamma rays of the gamma-ray detector 16, a gamma-ray count value (count of a part of gamma-rays) by the beta-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 beta-ray detector 12 by a second arithmetic part 28 so as to obtain measurements only of beta rays due to radioactivity detected on the body surface of a subject 100.
|
