A null balance technique for backscatter density gauges

A mathematical model for backscatter gauge detector characteristics (in their working environment) has produced a simple but precise null balance design for the backscatter measurement of density. This technique uses an equal-count principle which gives the method an independence from characteristic distortion as well as minimizing the systematic errors. The advantages of the moving-source gauge are contributory factors in the performance of this equal integrated count design for in situ or field measurement. A specified accuracy is maintained for periods of up to three months between situ-independent calibrations