STP293: Design and Calibration of a Neutron Moisture Meter

    Burn, KN
    Research Officer, National Research Conncil, Ottawa,

    Pages: 13    Published: Jan 1961


    Abstract

    A probe using an actinium-beryllium neutron source and a scintillation-type detector was designed and built for use in determining the moisture density in soils below the surface of the ground. A portable battery-operated sealer was selected to make it possible to use the equipment in places where there is no available a-c supply.

    Since the principle of the neutron moisture meter is based upon the physical interaction of neutrons with hydrogen atoms, considerable thought was given to the idea of calibrating the instrument in media other than actual soils; the advantages of using substitute materials are better uniformity and better control of both bulk density and distribution of hydrogen atoms.

    Requirements ol the artificial media are discussed and those adopted for calibration are described.


    Paper ID: STP39622S

    Committee/Subcommittee: D18.08

    DOI: 10.1520/STP39622S


    CrossRef ASTM International is a member of CrossRef.