Method and arrangement to reduce the influence of detector faults for X-ray scanners

In the X-ray scanner, the radiation penetrating the patient's body is measured by a number of detectors lying on the arc of a circle. Radiation source and detector system are rigidly linked with one another and are rotating about the body. By means of a computing circuit the offsets as well as the gains of the detector are corrected one after the other or alternately (method of iteration). For this purpose the computing circuit contains a memory and an averaging component, to the circuits of which the output voltages of the detectors are supplied, as well as a processor connected with the output of the averaging component. This one is succeeded by a sesend memory. The output of it and the output of the other memory are connected with a subtracter. If the method of iteration is to be applied the computing circuit is supplemented by a switch and a logarithmation and de-logarithmation unit. (DG)