| 摘要 |
PURPOSE:To reduce the influence of an external radiant ray, and to elevate the detection threshold, by providing a feed side pipe of a liquid and a delivery side pipe on the upper and lower parts, respectively, so as to place a radiant ray incident window between them, and providing a radiant ray shielding body on the outside of the opposite side of a measuring part pipe. CONSTITUTION:Bent parts 25, 26 are formed by bending a feed side pipe 10 and a delivery side pipe 11, and a radiant ray shielding body 6 is placed so that the radiant ray shielding body 6 having a radiant ray incident window 7 is placed between the bent part 25 and the bent part 26. A radiant ray detector 8 is incorporated in the radiant ray shielding body 6. A radiant ray shielding body 14 is provided on the outside of a measuring part pipe 5, that is to say, so as to be opposed to the surface of the measuring part pipe 5 at the opposite side against the surface opposed to the radiant ray shielding body 6 made of lead. In this regard, a rectifying body 2, a water pouring nozzle 3 and the measuring part pipe 5 are provided vertically on the front of the radiant ray incident window 7. |
