SECURITY ELEMENT FOR THE ELECTRONIC SURVEILLANCE OF ARTICLES

摘要

The invention is directed to a security element (3) for the electronic surveillance of articles. The object underlying the invention is to propose a security element that is detecting by surveillance system (S1, S2) operating in different frequency ranges (F1, F2). According to an embodiment of the security element of the invention, this object is accomplished by the following features: it is comprised of at least two materials (1; 2) of high permeability which, when excited by an external alternating magnetic field (H), emit each a characteristic signal (signal 1; signal 2); the maximum signal components of the two materials (1; 2) lie in different frequency ranges (F1; F2); and the signal components of the one material (1; 2) are negligibly low in that particular frequency range (F2; F1) in which the signal component of the other material (2; 1) is at a maximum lever.