Patent ID: 6740887
Filing Date: 2004-05-25
Classification: G01T

Abstract:
A method of investigating radioactive sources in a sample, the method comprising detecting a portion of the emissions arising from the sample at an energy, the detected portion relating to a detected level, the detected level being corrected according to a correction method to give a corrected level, at that energy, the correction method including:the provision of an emission generator, passing at least a portion of the emissions of the generator into the sample, detecting at least a portion of the emissions from the generator leaving the sample, and determining a value for a first determined relationship between the two portions; calculating a value for a relationship of equivalent type to the first determined relationship to provide a calculated relationship, the calculation being based on functions of an element's absorption of emission and the amount of that element potentially encountered by emissions, for one or more elements; adjusting one or more variables/functions in the caculated relationship to reduce the difference between the value of the first determined relationship and the value of the calculated relationship for the sample at a plurality of the energies of emissions from the generator, so giving a derived calculated relationship; and obtaining the forms of the one or more variables/functions of the derived calculated relationship and using those forms for the variables/functions in the calculation of the value of the calculated relationship at the sample source emission energy or energies requiring correction and correcting the detected level using those values for the calculated relationship.