Nondestructive testing apparatus for determining the orientation of

Abstract

A measuring apparatus which accurately locates reinforcing bars in underwater concrete structures such as piers, retaining walls, easements and the like and measures the amount of concrete covering each reinforcing bar. The measuring apparus comprises a probe which generates a magnetic field and which is moved over the surface of the underwater concrete structure under test. When the poles of the magnetic field are in parallel alignment with and directly over a reinforcing bar within the structure a disturbance occurs in the magnetic field with the magnitude of the disturbance being indicative of the depth of concrete covering the reinforcing bar. An electronics module electrically coupled to the probe provides an analog output signal which is indicative of the distance between a reinforcing bar within the concrete structure under test and the probe. This analog signal is supplied to a meter which provides a visual indication of the location of the reinforcing bar and a microprocessor which then calculates the depth of the reinforcing bar within the concrete sructure.