Patent ID: 7253414

Claim:
An apparatus for measuring an absolute value of at least one component of a bulk material, said apparatus comprising: a source of gamma radiation, said source emitting gamma radiation having at least three energy levels; at least one detector responsive to a continuous range of energy levels encompassing said at least three energy levels, said at least one detector and said source adapted for passing the bulk material between said at least one detector and said source; a first data set representing a measured gamma spectrum of the bulk material, said data set produced by said at least one detector; a processor in communication with said least one detector, said processor programmed to execute a process including: receiving said first data set, performing a least squares fit of said first data set with at least one library spectrum, determining a relative weight/impurity/component ratio of the bulk material from said first data set, and determining an absolute weight/impurity/component value from said relative weight/impurity/component ratio.