Lid and/or seal foil for an item of packaging and method for determining the opening state of an item of packaging

摘要

The foil has an electrical frequency generator unit (44) designed for co-operation with an antenna (26) formed on the foil by an antenna strip conductor such that the antenna or an associated electrical capacitance causes electrical energy to be supplied to the frequency generator. Electroconductive property of the foil influences an oscillation frequency of the frequency generator unit arranged on the foil. The frequency generator unit modulates an antenna signal of the antenna by the oscillation frequency. Independent claims are also included for the following: (1) a method for determining an opening state of a pack (2) a system for determining an opening state of a pack.