| 摘要 |
<p>Electronic monitoring of surfaces, in particular the boundary surfaces of sports grounds, is effected by means of surfaces superimposed at a distance apart in the monitoring region, at least one of which is flexible. When an object impinges on the contact surfaces, electrical contact is established between the surfaces and an electric and/or acoustic signal is generated. One contact surface is a resistor surface having constant surface resistance and the other contact surface is a conductive surface. A supply voltage is applied to at least two ends of the resistor surface through a corresponding dropping resistor. For the duration of contact between the contact surfaces, at least two voltage distributors are provided the voltages of which are proportional to the distance between the region of contact and the ends of the resistance path. Since each voltage corresponds to a definite point of impact, it is possible to determine when a ball overshoots a sports ground boundary line as well as the exact position of the ball.</p> |
