Measurement of Liquid/liquid Interfacial Tension with Water on Liquid Paraffin by the Floating Drop Method

•Interfacial tension between water and liquid paraffin was measured by floating drop method.•A clear submerged profile of a heavier water droplet floating on a lighter liquid paraffin was observed.•Larger droplet was found to improve the accuracy of the measured value based on measurement and simulation.•Floating drop method with a heavier droplet on a lighter liquid is an effectual method for interfacial tension measurement.