Determination of Water Viscosity by Tracking The Brownian Motion of a Single Particle using Video Microscopy

Abstract

Micron sized particle exhibits Brownian Motion (BM) in fluidic material. The BM of the particle characterizes the vicinity material due to the existance of thermal force. This paper describes an experiment to determine the water viscosity via BM observation using video microscopy technique. Video microscopy technique using open source Tracker software were employed to track the temporal displacement of the microparticle as a probe. Our viscosity measurement results (906 μPa s at 25.9 oC, 839 μPa s at 26.0 oC and 867 μPa s at 30.1 oC) are within the range resulted by measurement using rheometer. One of the merit of using particle tracking technique is the requirement of only microliter sample.