Abstract: An apparatus and method of non-contacting, non-destructive, on-line dimensional analysis and flaw detection of tubular products are disclosed. The apparatus includes penetrating radiation sources and detectors arranged about the product to be examined and a high-speed data processing system which employs novel computed tomography techniques to provide high precision dimensional estimates and flaw detection. The apparatus is capable of continuously determining the outside diameter, inside diameter, wall thickness, ovality, eccentricity, and weight-per-foot over a wide range of temperatures for essentially tubular products produced on a unit or continuous basis. The apparatus can also detect process-induced flaws in the products.