The magnetic crack definer (MCD) is a highly portable unit for use as an inspection tool to define fatigue cracks in steel highway bridge structures. A companion unit, the acoustic crack detector (ACD), is recommended for use as a survey inspection tool to initially detect the existence of fatigue crack and its location. The MCD employs an AC magnetic field and two inductive pickup devices which detect the existence of a crack where it penetrates to surfaces that are accessible. Audible and visual signals are produced when one or the other of the sensing coils is over the crack and positioned properly with respect to the crack direction. The MCD requires no adjustments by the operator and with only limited training personnel without previous experience with the instrument can use it effectively. /FHWA/

  • Corporate Authors:

    Federal Highway Administration

    Office of Research and Development, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Publication Date: 1975-1

Media Info

  • Pagination: n.p.

Subject/Index Terms

Filing Info

  • Accession Number: 00179465
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: FHWA-RD-75-504
  • Files: TRIS, USDOT
  • Created Date: Aug 27 1978 12:00AM