Patent ID: 6744366
Filing Date: 2004-06-01
Classification: G08B

Abstract:
A method of obtaining security tag operation capable of monitoring against disturbance made to an object, comprising:in the presence of the earth field installing one or more magnetic markers to jointly create a magnetic profile characteristic of the local environment of said object whose magnitude is measured by using one or more magnetic sensors installed at a position or positions at the enclosure or surrounding of said object, wherein by checking against said magnetic profile measured by said one or more magnetic sensors said disturbance can be identified, indicating security violations, which are induced by a condition of unauthorized relative movement of said one or more magnetic markers with respect to said one or more magnetic sensors resulting from breakage, distortion, or interruption of said object and/or its enclosure, and separately by a condition of alteration of a sensed magnetic field resulting from an external source or sources other than said one or more magnetic markers as a result of security failure, and alerting an alarm or warning in response to either of said conditions thereby realizing said security tag operation.