British standard BS1377 is concerned with methods of test for soils for engineering purposes. The author refers to two items in the 1975 revision which require careful attention by all who use hydrometers for particle size tests on soils. The first, and more significant, follows from the use of a new type of hydrometer which is now specified. This new hydrometer has to be calibrated to read 1.000 at 20 degrees C whereas the previous hydrometer was simply required to be calibrated in g/ml at 20 degrees C. This difference could lead to inconsistencies in the reporting of the clay fraction of soils based on the hydrometer sedimentation tests, because the new procedure will give results different from those obtained by following the 1967 standard. The second relates to the use of consistent units in the calibration of hydrometers. This note describes the new hydrometer and the old, and indicates how the old hydrometers can be used to comply with the 1975 revision if the new hydrometers are not available. A simplified procedure is also suggested. /TRRL/

  • Availability:
  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Authors:
    • HEAD, K H
  • Publication Date: 1976-10

Media Info

  • Features: Figures; Tables;
  • Pagination: 2 p.
  • Serial:
    • Volume: 9
    • Issue Number: 7
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00149067
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Analytic
  • Files: ITRD, TRIS
  • Created Date: Jun 22 1977 12:00AM