A New Method of Measurement of Sedimentation Potential at High Centrifugal Field

• Published in: Japanese Journal of Applied Physics Vol. 3; no. 7; p. 409
• Main Author: Matsukura, Yasuo
• Format: Journal Article
• Language: English
• Published: 01.07.1964
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.3.409

A new method of measuring sedimentation potential at high centrifugal field is described for the purpose of investigating the charge effects on sedimentation of macromolecules, and of determining the transference number of ions. At a high speed of rotation a large electromotive force of sedimentation potential is obtained, because the emf produced by the rotation should increase with the square of the number of rotation per second. In the present method, a condenser commutator was designed to avoid poor contact in the case of the common mercury contact at high speed of rotation, and to eliminate the production of thermo-electromotive force at the point of contact. For the calibration of the sedimentation potential, a combination of solar batteries and light sources was used as a standard cell. The potential can be measured with this apparatus with an accuracy higher than 0.1 mV at the speed of rotation from 1000 to 11100 r.p.m.