The Use of Hall Effect Semiconductors in Geotechnical Instrumentation

    Volume 12, Issue 1 (March 1989)

    ISSN: 0149-6115

    CODEN: GTJOAD

    Page Count: 8


    Clayton, CRI
    research student, and research student, University of Surrey, Guildford, Surrey

    Khatrush, SA
    research student, and research student, University of Surrey, Guildford, Surrey

    Bica, AVD
    research student, and research student, University of Surrey, Guildford, Surrey

    Siddique, A
    research student, and research student, University of Surrey, Guildford, Surrey

    Abstract

    For the past five years or so Hall effect semiconductors have been increasingly used in the geotechnical engineering laboratories at the University of Surrey. They have been incorporated as sensing elements in local radial and axial strain measuring devices, for the small-strain instrumentation of triaxial specimens, and in small diameter boundary normal and shear stress cells. Triaxial internal load cells are currently being built incorporating Hall effect semiconductors.

    This paper describes the Hall effect principle and the methods of configuring magnet/sensor systems to achieve suitable measuring systems. Some geotechnical instruments built at the University of Surrey are detailed, and their characteristics discussed. The calibrations of the instruments described in the paper show a performance generally at least as good as might be expected from some commercially available instruments. Hall effect semiconductors are shown to be of use in a range of situations where displacement can form the basis of measurement. The displacements measured can vary from as little as 5 µm to as much as 10 mm, and the best repeatability so far obtained has been of the order of 1/100 of a micrometre.


    Paper ID: GTJ10676J

    DOI: 10.1520/GTJ10676J

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    Author
    Title The Use of Hall Effect Semiconductors in Geotechnical Instrumentation
    Symposium , 0000-00-00
    Committee D18