| 摘要 |
<p>Target Apparatus A target apparatus, having a framework covered by sheets of material to form a chamber, the sheets of material being penetrable by a projectile, such as a bullet, fired at the target. A plurality of transducers are positioned at respective spacedapart locations within the chamber and lying on an arc of a circle, for detecting shock or pressure waves in the chamber caused upon penetration of the sheets of material by the projectile. Time differences between instants of detection of a shock or pressure wave by the transducers are measured, the location at which the projectile penetrated the sheet of material being determined from the time differences. Preferably, a bull's-eye or aiming mark is provided on the target, the center of which is aligned with the center of the circle on which the transducers lie. Apparatus is also disclosed for determining the speed of sound in air within the chamber, enabling the projectile penetration point to be determined with particular accuracy.</p> |
