Count-Rate Instability in Gamma-Ray Transmission Equipment
1974
Reginato, R. J. (Robert J.)
Significant errors in measuring the bulk density and water content of soils can result from a procedure commonly used with gamma-ray transmission equipment. The detector probe can be exposed directly to the unattenuated gamma-ray source when moving from a standard absorber to the soil. Under this high-exposure condition, 20 to 30 min may be required before the system will stabilize and reliable count rates can be taken. To avoid this difficulty, three alternative techniques are suggested. The alternative found most desirable for existing conditions was to take a standard count rate in the soil pedon where the bulk density remained constant, thus eliminating the necessity of exposing the detector to the unattenuated gamma-ray source.
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