From abstract: "A scintillation detector has a pulse height output which is a linear function of the energy of impinging gamma radiation. A pulse height analyzer system determines the amplitude distribution of this train of pulses. The system also displays this information graphically in a form which is convenient for further analysis."

Abstract: Both direct and coincidence counting apparatus are described. The elimination of cosmic ray events by coincidence plus gamma ray shielding permits the reduction of counting rates far beyond that obtainable with shielding alone. By selection of materials and development of new components and techniques, the residual background count of beta counting equipment can be reduced to a very low value. Geiger counter equipment for routine laboratory measurements is described, have a background count of 0.7 c/m. Scintillation counters are shown to have a background of 0.2 c/m at 30% efficiency. A portable Geiger counter with a 3.7 c/m background is also described.