Determination of Interfacial Tension by Video Image Processing of Pendant Fluid Drops

摘要

A novel technique is presented for the determination of interfacial tension by analysis of axisymetric fluid drop profiles. The technique couples recent developments in digital image acquisition and processing with modern methods for robust shape comparison. The entire algorithm for drop profile acquisition and analysis is executable on a personal computer and includes a facility for rotationally resistant smoothing of the drop profile. The general performance of the robust shape comparison algorithm and improvement in accuracy resulting from smoothing is illustrated by analysis of simulated pendant drop profiles. The overall performance of the image acquisition hardware and profile analysis software is assessed by evaluating the surface tension of glycerin. The resultant value of 62.6 + or - 0.3 dyn/cm (at 24.2 + or - 0.2 C) agrees well with the literature data for glycerin.