| 摘要 |
<p>A tamper detecting device for detecting tampering in a tamper-proof metal closure having shearable bridges which, when sheared, evidence tampering of the closure, such as a bottle cap for a drinks bottle. The tamper detecting device has a primary coil (20) and means (30) for locating the primary coil adjacent the shearable bridges of a closure. A level of inductance for the coil is measured, to detect whether the bridges have been sheared. Also, a tamper-proof closure for a bottle or jar, having a generally cylindrical screw cap and means for sealing the cap around the neck of the bottle or jar, further comprising a magnetic element (65) located beneath the cap, that is permanently magnetized to provide an authenticating magnetic signature for authentication of the closure, and a device for testing the authenticity of such a closure, the device comprising a sensor (66) for sensing the presence of a magnetized element located beneath the cap.</p> |
