The Determination Of Interfacial Tension By Video Image Processing Of Pendant Fluid Drops

A novel method for the analysis of interfacial tension from the shape of pendant fluid drops is presented. The experimental apparatus employs digital video image processing techniques to record drop images and to segment the fluid drop profile. An associated drop profile shape analysis algorithm is developed based upon robust shape comparison methods that utilize repeated median concepts. The complete algorithm is designed specifically to be executable on a microcomputer. The performance of the algorithm is illustrated for simulated pendant fluid drop profiles and pendant drops of glycerin. In the latter case, the experimental precision in the resultant surface tension is found to be of the order of 0.5%. Keywords include: Polymer Interfacial Tension, Pendant Drop, and Image Processing.