トラップを用いたマクラウド真空計による真空度測定の根本的欠陥について
水銀蒸気中における窒素の拡散の影響
1961 年 4 巻 10 号 p. 414-420
詳細
1961 年 4 巻 10 号 p. 414-420
In the calibration of ionization gauges against the standard McLeod gauge, it has been observed that the sensitivity of the ionization gauge varies with the room temperature in many experiments, sometimes up to 25%. After the careful consideration, it is deduced that this phenomenon is mainly due to the mercury vapour stream from the McLeod gauge to the cold trap inserted in the line to the ionization gauge manifold. A way to remove this obstacle is solved by cooling the cut-off position of the McLeod gauge. Theoretical treatments by means of the diffusion of nitrogen in the mercury vapour stream sufficiently agree with experimental results. Some analogous problems on vacuum technique are discussed.
