FACTORS LIMITING THE ACCURACY OF MEASUREMENTS OF SURFACE-TENSION BY THE SESSILE DROP METHOD

Different sources of error in determining surface tension by the sessile drop technique are discussed. The influence of uncertainties in measuring drop co-ordinates are quantitatively evaluated, and the results tested on Ag and Pb drops at different temperatures. Shifts in surface tension values, due to errors in determining the exact scale factor and to errors in reading temperature or density, are calculated, and a nomographic chart, to find the optimum drop weight, is also presented.