Abstract: The invention relates to a method for measuring the thickness of non-circular elongated workpieces in which the thickness of the workpiece is measured along three measuring axis, the measurements are fed into a computer to determine minimum and maximum values and associated angular positions of the measuring axis, the measuring systems are rotated to a zero measuring position and the measured thicknesses are correlated by an algorithm, and the computer computes the degree for which angular position of the mimimum and maximum changes when the workpiece is advanced.

Abstract: The invention related to positioning and marking a patient at a diagnostic apparatus, for example before and after a fluoroscopic examination in a computer tomograph comprising at least four line lasers being movably supported for travelling along a respective axis, two line lasers being arranged above a patient placed on a movable table projecting a sagittal line and a transverse line on the body of the patient and two further line lines arranges sidewards of the table each projecting a line along the body axis sidewards on the body, further comprising numerically controlled drive means for moving the line lasers to adjust the projected lines in a transverse direction and comprising a positioning control device, controlling the drive means and a manually operated input device for supplying the coordinates, the location and extension of the radiation zone as determined by the computer tomograph for being supplies to the control device, and projecting orthogonal coordinate axes on the patient for marking the p