FILTEREINRICHTUNG FUER EIN GERAET ZUR ANALYSE VON METALLEN DURCH ROENTGENSTRAHLEN-FLUORESZENZ

摘要

An analysis device for analysing X-ray radiation from a sample of material, e.g. for X-ray fluorescence analysis of a metal alloy, includes a radiation detector (592) and an X-ray radiation filter means (52). The filter means (52) has a plurality of filters (741) positioned adjacent the periphery of a disc (743) which can be rotated selectively to position each of the filters (741) between the sample and the radiation detector (592). The disc is driven by an electric motor through a geneva drive means. Each of the filters comprises a filter bracket attached to the disc (743) with a sheet of filter material mounted on it which preferentially passes the spectral lines of a predetermined chemical element. A plurality of photodiodes are positioned on one side of the path of travel of the filter brackets and a plurality of associated photo transistors are positioned on the other side. Each filter bracket includes areas which are either opaque or transparent so that the absence and presence of the light enables the phototransistors to generate a digital filter identification signal.