Abstract: A method for calibrating a system that includes a build chamber to accommodate powder to be melted and an object to be produced and a height-adjustable build plate support in the build chamber to support a build plate. The system also includes a controllable optical unit comprising (1) a laser source, (2) a plurality of lenses, and (3) a mirror arrangement having a plurality of adjustably arranged mirrors. The controllable optical unit is configured to selectively direct a laser beam to a point in the build chamber at which to melt the powder. The method includes placing a scanning field plate on the build plate support, creating a plurality of optical reference points on the scanning field plate, generating a measuring grid on the scanning field plate by adjusting the mirrors using a calibration data set, and determining a relative positioning between the optical reference points and the measuring grid.

Abstract: A carrier arrangement for use in a plant for producing items according to a method for selective powder melting by building layers made of powdery material. The carrier arrangement includes a building panel on which the item to be produced is built. The carrier arrangement includes a base panel permanently assigned to an external component of the plant. The carrier arrangement includes a clamping system to detachably connect the building panel to the base panel and to position the building panel at a clamping position such that, in a clamped state, the building panel is arranged above the base panel. The carrier arrangement includes a heating system comprising at least one heating element for emitting heat for heating the building panel, wherein the at least one heating element is arranged above the clamping position.