Speed and speed classes of film-screen systems

In order to carry out the DIN 6868, Part 50 (1988) acceptance test within the framework of measures of quality assurance, the dose of the film-screen combination used is needed in the plane of the cassette. Recent methods for determination of sensitivity use the film-screen system instead of artificial light and decisions can be made as to the dose of the cassette plane. In order to characterize the sensitivity, it is proposed to use a given scale of numbers for the sensitivity S in increments of Δ log S = 0.05 in numerical values. It will also be useful for practical purposes to employ the ''sensitivity class'' with 2-fold increments in order to bring the planned radiological specifications into agreement with the demands of the user. (author)