Nuclear gauges are one of the most accurate methods used to measure the moisture content and density of soils, aggregates, and other materials. These measurements are used for building roads and dams, and for collecting scientific data on soil water content in agricultural and forestry settings.
For a structure to stay in good condition, its soil and aggregate layers need to provide a stiff and stable foundation. A well-compacted base layer should be able to resist movement and deformation under stress. The density of in situ soils are therefore measured to ensure a structure’s performance and longevity meets industry standards.
A nuclear density gauge measures the density of in-place hot mix asphalt (HMA) using gamma radiation. Gamma rays are emitted from the source and interact with electrons in the material. By calculating the percentage of gamma rays returned to the source, the gauge can quickly and accurately measure the density and inner structure of the test material.
https://www.humboldtmfg.com/nuclear-gauges.html
In moar breaking news, device with radioactive materials in it goes missing. someone lost an old luminous watch