The non-destructive testing (NDT) industry is reviewed, the major techniques being described and current development directions and challenges identified. One of the most common techniques (ferroscan) is explained briefly below. Ferroscan is a non-destructive measuring method based on the generation and detection of electromagnetic fields in conductive materials. In concrete structures, the strength of this induced field depends on the diameter and the cover of the
reinforcement. The techniques has been shown to find location and orientation of reinforcement bars, stirrup, or other metal pipe, in the concrete, measure thickness of concrete cover over reinforcement bar, and to determine the bar diameter. In this paper Ferroscan FS 10, a portable detection, was used for measuring and mapping system which provides an immediate liquid crystal image of the reinforcement within a survey area which include reinforcement concrete beam
(1000*200*120)mm. The great advantage of measurements with ferroscan, compared to existing detection systems, is that the measurements can be carried out far quicker and more accurately, accurate mapping out of reinforcement and verification of reinforcement in old building.