1. An inspection system for inspecting a three-dimensional volume, comprising; at least one sensor coupled to a rolling object, wherein the at least one sensor is disposed on a non-contact outer region of the rolling object and at a pre-determined distance from a center of the rolling object; wherein the at least one sensor is configured to generate signals representative of a condition of a region on the three dimensional volume; and a data analyzer configured to analyze the signals to determine the condition of the three-dimensional volume at specific locations therein.