[Speed S sensitivity of film-screen systems and mode of action of different automatic illumination in general practice. I: Film-screen systems].
A new test procedure is presented to check the correspondence between various screen-film systems (SFS) with the specification of the manufacturer in respect to the speed S according to DIN 6867-1 or rather which dose K is required for the SFS in dependence on the X-ray tube voltage (kV) to give the net density Dn = 1.00, it is based on measurements of dose and density using on X-ray equipment with water as an absorber and scatter test tool. The characteristic curves of the automatic exposure control (AEC) can be recorded and compared with those of SFS, i.e., how is the dose K in the image-receptor-plane regulated by the AEC in dependence on different radiation qualities. It is also possible to check the modes of operation of SFS and AEC with sufficient accuracy but lower time and energy requirements. The consequences of finding the right values to test the X-ray equipment under DIN 6868-50/-3 and for constancy-testing according to DIN 6868-3 are discussed.