In order to measure the volume of evolved hydrogen, the weldments are usually immersed in a bath of mercury or glycerin, as called substitution method. The total hydrogen content, however, is measured smaller by using glycerin than by using mercury under same conditions.
In this study, the volume of gaseous hydrogen (H
2) and the evolved hydrogen (H) from hydrogenated steel specimen were measured by the substitution method, using mercury, glycerin, 6N-K
2CO
3 and ION-K
2CO
3 as collecting solution.
The accuracy of the hydrogen measurements for various collecting solutions were discussed and the results were summerized as follows;
(1) In the case of using glycerin, the experimental errors appeared easily. Above errors were mainly caused by absorbtion of hydrogen bubbles on measurement wall, remain and dissolution in glycerin.
(2) The 6N-K
2CO
3 solution did not absorbed gaseous hydrogen, but absorbed the evolved hydrogen from specimen.
(3) In the case of using 10N-K
2CO
3 collecting solution at 35°C the results obtained were satisfactory for determination of the evolved hydrogen in same manner as using mercury.
(4) Hydrogen content can be measured with a high accuracy by using mercury, but point to which special attention should be paid is the health for the operator because of mercury vapour.
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