1955 年 5 巻 11 号 p. 554-557
The writers have tried to manufacture a practical level gauge both for remote measurement and remote control of liquid level which is contained in a closed vessel or which does not allow the access of measuring instrument. For this purpose, the γ rays from Co60 were irradiated either parallel or inclined 30° to the surface of the liquid in a hollow cylinder made of iron or glass through its side wall. After measuring the amount of the rays passed through the cylinder with a counting-ratemeter combined with a G M counter, the relations were checked between the liquid level and the amount of the rays passed. In this article appear four cases of the many experiments conducted, of which the most accurate one shows that the level may be determined within ±0.3mm. Some cautions in manufacturing the ratemeter, protection against the γ rays irradiated, etc. are also given.