Mathematical model validates multipeak backscatter detector characteristics

Backscatter gauges are used to obtain a nonintrusive measurement of the density of bulk materials from the surface. A mathematical model, which accurately represents the detector in its working environment, has been developed. Since the initial conception of a moving source albedo density gauge, there has been speculation that a broadening of the peak or multipeaking exists with hydrogen containing materials. A more sensitive version of this gauge was designed to facilitate a detailed investigation of these materials. Any difference in a detector characteristic is highlighted by a comparison of the theoretical maximum and normalised shape provided by the three-dimensional surface model. This has allowed the presence of larger than previously experienced hydrogen peaks to be verified. A simple explanation of this distortion of the three-dimensional surface model by hydrogen containing materials is given.