| 摘要 |
PURPOSE:To accurately measure an adsorbing amount by preventing the temp. of a cooling medium from becoming unstable by replenishment without replenishing the cooling medium, by calculating the change in the liquid level of the cooling medium with the elapse of time on the way of measurement and correcting the volume of a space part at the point of time when each adsorption equlibrium pressure is measured. CONSTITUTION:A gas sump part 2 is connected to a specimen cell 1 having a specimen W sealed therein through an opening/closing valve 3 and a N2 cylinder, a He cylinder and a vacuum pump are connected to the sump part. The vacuum degree and pressure in the sump part 2 are measured by the vacuum gauge 14 and pressure gauge 15 provided in said sump part 2. The volume Vd (the volume Vb+Vc above and below a LN2 level 7a) of the space part in the cell 1 is measured by the graduations 1a of the cell 1. The change in the LN2 level 7a with the elapse of time on the way of measurement is calculated and volumes Vb, Vc at the point of time when each adsorption equilibrium pressure P2 is measured are corrected. The temps. Tb, Tc of the parts corresponding to the volumes Vb, Vc are prevented from becoming unstable without replenishing H2 and the adsorption quantity of N2 of the specimen W is accurately measured.
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