Measurement of surface tension coefficients of liquids based on equal thickness interference

TL;DR

This paper introduces a new interference-based method for accurately measuring liquid surface tension coefficients, reducing errors associated with traditional rupture-based techniques and enabling applications to interfacial tension measurements.

Contribution

A novel equal thickness interference method for precise surface tension measurement, with advantages of high accuracy, low cost, and broad applicability.

Findings

Maximum measurement error less than 3.1%

Method applicable to liquid-liquid interfacial tension

Demonstrates high accuracy and simplicity

Abstract

The surface tension coefficient is a key parameter in fluid mechanics. The conventional method to measure it is to determine the critical surface tension that causes the rupture of a liquid film. However, this method has a large error because the surface tension coefficient is very sensitive to environmental factors. In this paper, we propose a new method based on equal thickness interference to study the mathematical model of the stationary liquid surface shape and measure it by the interference technique. This method enables the accurate measurement of the liquid surface tension coefficient. The experimental results demonstrate that this method has the advantages of high accuracy, low cost, and simple instrumentation. The maximum measurement error is less than 3.1\%. Moreover, this method can be applied to measure the liquid-liquid interfacial tension, which has a good application prospect.