[Quality assurance through constancy control for x-ray film processors (author's transl)].

A control method to check the reproduction of x-Ray film processors and necessary instruments is presented. The application of a light sensitometer allows the production of test films daily, independent of x-Ray exposures, x-ray film cassettes and x-ray intensifying screens. The optical densities on the test films will be read by means of a densitometer and the results are plotted on a special control chart. A limitation through optical densities of +/- 0,15 for Speed Index and +/- 0,20 for Contrast Index determines the tolerance variation for x-ray film processors. Targets of this control method are uniform image quality, dose reduction and saving of cost.