DESIGN AND DEVELOPMENT OF THE MAGNETIC CANTILEVER EXTENSOMETER

The design and development of a new multi-position borehole extensometer is described. Details of this form of instrumentation include small button magnets located on the borehole sides for reference purposes, whilst a probe is guided in a flexible grooved casing for locating the precise centre of a reference point and a depth monitor fixes its vertical position. Distance/output response of the probe is of normal wave-form, the peak coinciding with the centre of the magnet thus locating the reference points positively. Results of laboratory feasibility studies and the borehole simulation survey are included. The instrumentation has a special application in boreholes where drilling of a long, straight borehole is not always possible. /Author/TRRL/

  • Availability:
  • Corporate Authors:

    Pergamon Press, Incorporated

    Headington Hill Hall
    Oxford OX30BW,   England 
  • Authors:
    • SMART, BGD
    • SINGH, R N
    • Isaac, A K
  • Publication Date: 1978-12

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Filing Info

  • Accession Number: 00195471
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Sep 15 1979 12:00AM