An apparatus is provided for quantitatively measuring samples whose amount or
other characteristic quality is to be determined. The samples are arranged in a
predefined pattern and are excited in a magnetic field. The magnetizations of the
magnetic particles are thereby caused to oscillate at the excitation frequency
in the manner of a dipole to create their own fields. These fields are inductively
coupled to at least one substantially flat sensor such as sensing coils fabricated
in a gradiometer configuration.
