MASS MEASURING INSTRUMENT FOR HETEROGENEOUS MATERIAL ON BASE MATERIAL BY BETA RAY

摘要

PURPOSE:To reduce the size of an instrument and to take measurement without destroying a raw material by uniting and storing a beta-ray radiation source and an annular semiconductor detector in a container. CONSTITUTION:The beta-ray source 1 is fitted behind the annular Si semiconduc tor detector 2 and they are united and stored in the lead container 3. The intensi ty of the beta-ray source 1 may be, for example, =100 microcurie. A primary beta ray 4 is projected on a base material 7 from the beta-ray source 1. If there is a heterogeneous material 6 on the base material 7, the beta ray is absorbed corresponding to its amount and backward-scattered beta ray 5 is scattered. The backward-scattered beta ray 5 is detected by the detector 2 to find the mass of the heterogeneous material 7. Thus, the radiation source and annular semiconductor are united, so the instrument is reduced in size, measurement is taken even in a narrow place, and the coating film on the base material, oxide layer of an iron plate, etc., can be measured effectively.