MEASUREMENT OF THE VISCOSITY COEFFICIENT OF LIQUID BY THE INTERFEROMETRY

Based on the capillary method for measuring the viscosity coefficient of liquids, an experimental method for measuring the viscosity coefficient of liquid by optical interferometry was proposed. This method combines the capillary method device with the Mach-Zehnder interferometer and measures the changes in optical distance instead of measuring the changes in height of liquid surface, by which the viscosity coefficient of liquid will be obtained by measuring the relationship between the number of interference fringes moving and time. The viscosity coefficient of pure water at room temperature was measured by this experimental device. Through error analysis, it was found that this method has good measurement accuracy. The experimental device combines fluid mechanics experiments with optical experiments, which can effectively cultivate students' comprehensive experimental abilities.