| 摘要 |
<p>An electronic measuring device 7 with audible and or visual indication which in use can be placed on or astride the top of a tennis net and which will indicate the height of the tennis net above the ground. Preferably the measurements are taken using ultrasound, LASER or infra red technology. Optionally the device may include a display 9 to indicate the measured height and include an audible indication. Logic means can be provided for receiving signals from sensors and control buttons 10a-d and for driving a display or sound generating device. The device can have multiple sensors and may indicate if it is incorrectly mounted on the tennis net.</p> |
