Measurement of liquid surface tension by fitting the lying droplet profile

Abstract This study developed a simple drop-shape method to measure liquid surface tension based on curve fitting technique. In this study, the explicit lying droplet profile function in terms of surface tension was derived by solving 2-D Young-Laplace equation exactly, and the derived profile function was superior to the existing approximate profile functions. By fitting the derived profile function with the detected droplet profile image data, the liquid surface tension was then obtained. Also, the measurement deviations of the proposed method have been analyzed. The proposed method does not rely on any new instrument, it is quite different in principle and simpler than the traditional methods.