Determining properties of magnetic elements

Abstract

A method of determining differing characteristics of magnetic dipole elements such as orientation, coercivity, bias and response amplitude and a tag reader for reading magnetic tags containing such elements. The elements are scanned by a rotating magnetic field and two sets of transition data are determined. The transition data sets are associated with respective elements and analyzed to determine mean field values resolved along the element vectors. These field values are used to determine properties of the elements, such as coercivity.

1 . A method of reading a magnetic tag having at least one magnetic element, comprising: 
 interrogating the tag with a scanning magnetic field;    determining transition data associated with changes in the magnetization state of the at least one magnetic element;    associating the transition data with one or more respective elements; and    for each element, determining the element direction which corresponds to the transition data for that element.    
     
     
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