title: Appartus for high-resolution surface tension measurement.
abstract: We describe an apparatus for measuring surface tension of insulating liquids by capacitive sensing of capillary rise. Two guarded coaxial capacitors with different gap widths are connected to permit liquid to flow between them. The higher capillary rise in the narrow-gap capacitor is balanced by a dc voltage applied to the wide capacitor by a servosystem. In a measurements of the surface tension of liquid helium we obtain a resolution of 1 part in 10(5). The technique is well suited for automated measurements of small changes in surface tension.
authors.affiliation: Department of Physics, University of Michigan, Ann Arbor, Michigan 48104.
authors.forename: J H
authors.initials: JH
authors.lastname: Magerlein
authors.forename: T M
authors.initials: TM
authors.lastname: Sanders