| 摘要 |
PURPOSE:To improve measuring accuracy, by projecting thermal neutrons in the thickness direction of a material, whose temperature is to be measured, measuring the number of gamma rays, which capture the discharged neutrons, and measuring the average temperature in the thickness direction based on the counted value of the gamma rays and the measured result of the thickness of the material. CONSTITUTION:Thermal neutrons 3 are projected to an iron plate 1 from a neutron ray source 2. Discharged, neutron capturing gamma rays 5 are counted 9 by a counter 8 through a gamma ray detector 6 and a wave height discriminator 7. The thickness of the iron plate 1 is measured by a gamma ray plate thickness meter comprising a gamma ray source 10, a gamma ray detector 11, and a plate thickness operating circuit 12. Since the thickness and the counted number 9 have a relationship of unitary sense, an internal average temperature 14 in the plate thickness direction is determined by a temperature operating circuit 13. With respect to the same internal average temperature 14, (a) having the small thickness has the large counted number 9 than that of (b) having the large thickness. |
