Multi-layer or single layer pipe on-line measurement. SCITEQ-X-ACT TwinEye uses advanced x-ray scanning technology with two projections (X-ray arrays) to measure single layer or multi-layer pipes on-line. The use of two X-ray arrays secures a fast and accurate dimensional single and multi layer measurement independent of the pipe position through the scanner. The unique and patented technique provides accurate measurement of individual layer thicknesses, densities and ovality of most multi-layer pipe constructions. The measurement technique is non-destructive and completely temperature independent. The unit can be used on or off line; it can even be moved from one line to another without having to stop the extrusion process thanks to its innovative mechanical construction.