Skin friction is one of the most important variables to determine in fluid mechanics. Most of the existing methods to measure the skin friction are intrusive, and thus accuracy of the measurement deteriorates when the flow becomes complex. A recently proposed method using laser interferometry is nonintrusive, and is known to have several advantages over the existing methods. The main focus of this research is given on the set-up of Laser Interferometer Skin Friction Meter (LISF) and its validation. For validation of LISF, measurement of skin friction in a transitional boundary layer over a finite length flat plate is carried out. The velocity profiles in the boundary layer is also measured by using Hot-wire anemometer system. The skin friction coefficients from LISF and from the Clauser's plot of the velocity profile are compared.
