Development and Industry Acceptance of Nuclear Gauges Available to Purchase

Mr. William F. Troxler delivered the keynote speech at the ASTM SYMPOSIUM ON CONSTRUCTION AND CONTROLLING COMPACTION OF EARTH FILLS, presented on July 1, 1999 in Seattle, Washington. As an original contributor to in-situ moisture and density measurement, Mr. Troxler detailed the history of how these devices were developed and accepted in the construction industry.

Beginning with his early work for the US Department of Agriculture and NC State University School of Agriculture to develop a device to measure the water content, Mr. Troxler describes how this device was combined with a similar device that measures the density of soils to create the surface moisture/density gauges used in the highway construction industry. The first models of this device were unacceptable because of the errors created by the chemical composition and other factors. Mr. Troxler explains how the development of calibration blocks with permanent density and moisture content values improved the gauge precision to the extent that the devices were more precise than current methods employed in the industry. Additional points of interest are included to explain how the nuclear moisture/density gauge became a standard test method in the industry.