Patent Number: 
Section: abstract

An X-ray device with an X-ray source to produce a beam of X-ray radiation, an X-ray detector to detect this radiation and an X-ray filter with filter elements which is positioned between the X-ray source and the X-ray detector to attenuate the X-ray beam in each independent filter element individually. Even filter element (213) can contain a fluid (32) which is electrically conducting and X-ray absorbing, which is supplied via a transport channel (30), whereas the value of the X-ray absorption of each filter element can discretely adjusted by a stepwise adjustment of the level of the fluid (32) within each filter element. Each filter element comprises a first electrode, which is located in the wall of the filter element and is segmented in the length direction of the filter element (213), the segments being electrically combined in tow subgroups (213, 124) in order to apply an electric potential to the wall segments of the filter element to achieve a step-wise filling of the inner volume (31) by fluid (32). The measuring means (50, 60) are provided to detect the length of the fluid column (32) within the inner volume (31) of the filter element (213).