Abstract: Concentrator for detecting defects in a ferromagnetic object comprises flux concentrator, typically fixed in a center of the device, which has two or more magnet assemblies disposed at each end of flux concentrator for saturating the ferromagnetic object passing through the device or where device is passing over the ferromagnetic object. Leaked flux emanated from the ferromagnetic objects due to defects in the ferromagnetic object is captured by the flux concentrator and channelized onto sensors embedded in the flux concentrator. Data gathered by the sensors may be processed for exploring nature and characteristics of the defects in the ferromagnetic object.