| 摘要 |
<p>Coins to be examined and/or validated are deposited into a chute (2, 5) defining a guide passage (8). First and second inductive coils (4) are supported on opposite sides of the guide passage (8). A sensor head (3) having a front profiled surface (9) faces the passage (8) and a stop (7) is provided to arrest a deposited coin (6) within the passage such that the coin rests against the profiled surface (9). The surface (9) is shaped such that the spacing between the coin (6) and the surface (9) depends upon the thickness and diameter of the coin. With the coin held in position against the profiled surface (9) one or both of the inductive coils (4) is energised to subject the coin to one or more electromagnetic signals and produce an output indicative of the effect of the coin on the or each electromagnetic signal. As the coin is held stationary whilst measurements are made a high degree of accuracy can be achieved. <IMAGE></p> |
