| 摘要 |
A target device for ascertaining the proximity of a hit to the target center comprises a plurality of transducers separated from one another in a space behind the target surface and positioned to respond to the impact shock at times determined by the sound propagation velocity in the air of this compartment. To increase the accuracy of the device, means is provided to provide an essentially constant temperature gradient (or uniform temperature) in the space or compartment and/or one sensor more than that required for determining the position of impact when the sound propagation velocity is known, is used. |
