Method for calibrating at least one scanning system of an SLS or SLM installation

A method of calibrating at least one scanning system of a laser sinter or laser melt facility, the at least one scanning system comprising at least one laser beam source directed onto a construction field in order by a construction process to melt or fuse a construction material capable of sintering or melting and thus through its cooling selectively to solidify such construction material, the method comprising:

• generating through the at least one scanning system, at least one line pattern on a surface at the level of the construction field, wherein generating the at least one line pattern comprises:
• projecting, by the at least one scanning system, the at least one line pattern on an upper surface of a calibration plate provided with a specified line pattern permanently applied thereto;
• recording with a camera disposed over a construction field and reading into a memory, a deviation of the at least one line pattern produced by at least one scanning system from the specified line pattern;
• executing, by a processor, a field correction of the at least one line pattern by calculation of correction data regarding the at least one scanning system, the correction data containing information for correction of any distortions of the at least one line pattern;
• and
• measuring and correcting, by the processor, the deviation of the at least one line pattern visible on the surface of the calibration plate and recordable with the camera over the construction field so that the at least line pattern produced by the scanning system coincides with the specified line pattern permanently applied to the calibration plate.