Measuring sweet spots of tennis rackets

Measuring and analysis procedures are presented in this paper to study the first two sweet spots of a tennis racket. After a brief description of sweet spots in racket, we describe the experimental procedures applied in this work. Reproducing realistically the boundary conditions at the grip of the racket is a major difficulty that is tackled here in a simple manner. Instrumentation and signal processing issues are discussed. Using digital filtering to extract time domain signals and comparing time signals from different locations on a racket, mode shapes have been identified. Test results are presented and sweet spots are identified for rackets with large and small heads, and for high or low string tension.