Method of measuring the cross-sectional area of magnetic reinforcing

Abstract

A method and apparatus for detecting a loss in cross-sectional area of metallic reinforcing members having magnetic properties of a conductor indicating corrosion effects on the conductor. The method comprises providing a motive force to move a data collection component and a detector component along a length of conductor. The detector includes a rotating magnetic source spaced apart from an electronic coil winding. In use, a conductor is interpositioned between the magnetic source and electronic coil winding. The amount of magnetic field passing through the conductor induces a voltage in the coil inversely proportional to the cross-sectional area of the steel reinforcing strands of a conductor. The described apparatus can be used to determine the rate of loss of cross-sectional area for a conductor over a period of in use by measuring the cross-sectional areas of the metallic reinforcing members over an adequate time interval. Alternatively, the cross-sectional area of a new conductor can be compared to the cross-sectional area of a conductor in use for a known period of time to estimate a rate of loss of cross-sectional area. This determination can be compared to a minimum baseline cross-sectional area indicative of imminent failure to estimate the remaining useful life of the conductor in use.