Effect of Physical Adsorption of Water Vapour on Evacuation Process of Vacuum Apparatus
1962 年 31 巻 2 号 p. 142-145
詳細
1962 年 31 巻 2 号 p. 142-145
The effect of physical adsorption of water vapour on production of high vacuum is discussed.
As the life time of water molecules adsorbed on lead borosilicate glass at 10-6 Torr, 0_??_50°C, is about 5_??_10×10-4 sec, the adsorption very rapidly reaches an equilibrium state. Henry's law holds in the pressure region of 10-6 Torr where Henry's canstants k at 0°C and 25°C are 15_??_20 and 4_??_7 respectively.
For evacuation of a vessel of volume V, actual volume becomes V+kA because of the adsorption of water vapour where A is the true surface area of inner walls of the vessel.
