Measurement of Surface Tension and Capillary Wave Velocity at Different Temperature by Laser Diffraction

Surface tension and capillary wave velocity are measured at different temperature by laser diffraction from capillary waves.When the laser beam obliquely impinges on capillary waves at a certain angle,steady and visible diffraction spots are formed.Surface tension and capillary wave velocity at different temperature are measured by laser diffraction.By the non-linear least square fit to the data,the analytic expression of surface tension and temperature is derived,and the analytic expression of capillary wave velocity and temperature is derived.Surface tension and capillary wave velocity all decrease with the increasing temperature,and the approximate relations of them are linear.Based on the principle of this experiment,a new method for measurement of surface tension and capillary wave velocity at different temperature is built in a real time and non-destructive way.