Apparatus (2) for characterizing or identifying an article (10) having a magnetic material thereon which stores information relating to the article, the apparatus comprising means (24) for irradiating the article with electromagnetic radiation of a particular spectral characteristic, means (26,28,30)...http://www.google.com/patents/US4908516?utm_source=gb-gplus-sharePatent US4908516 - Apparatus and process for checking the authenticity of an article having a magnetic storage information means
