| 摘要 |
<p>This device comprises a base (10) provided with a support (11) intended to clamp a racket (14) by means of its handle (15) held by a jaw (12) and a locking screw (13). The strings (16) of the racket (14) are struck with the aid of a weight (18) to make them vibrate. The vibrations cause a variation in the pressure of the air which is detected by an acoustic sensor (17) combined with a frequency meter intended to determine the frequency of the vibrations. The string tension, which is directly proportional to the frequency of the vibrations, is displayed on a screen (21). This device is used particularly for measuring the tension of tennis racket strings. <IMAGE></p> |
