What does a nuclear gauge measure?

• A. In-Situ Density And Moisture Content Of Soil
• B. In-Situ Density Only
• C. Moisture Content Only
• D. Surface Moisture

Answer: (A)

A nuclear gauge is built to gauge two properties of the soil right where it sits: how compacted the soil is (density) and how much moisture it contains. It does this with two different signals in one device. Gamma rays are used to assess density because the amount of gamma radiation that travels through the soil changes with how much material is present between the source and detector. Fast neutrons are used to assess moisture content because hydrogen in water slows neutrons, so the detected neutron signal varies with how much water is in the soil. Together, these readings give you in-situ density and moisture content of the soil. It’s not limited to moisture alone, nor to surface moisture, and it provides both measurements rather than just one.