Speed in tennis

After a six-year research, a tennis speedball analyser (TSA), has been developed by Toucon SA, Verbier, Switzerland and a government sponsored company. The graphite racket features a unique software with a microchip in its handle, powered by a lithium battery. This software calculates the speed of the ball through the data obtained from sensors attached to the six central strings. The manufacturer of TSA claims that the radar gun which is used at present to measure the speed of a tennis ball, only measures the serve. It is less accurate because it calculates the speed about three feet from the racket ( Electronic Product Design , June 1997).