The Design of a Microdensitometer

The evaluation of photographic line patterns is discussed with the object of comparing various procedures in their relation to the design of a microdensitometer. While some of the points discussed apply to the evaluation of optical spectra, the main interest of the discussion is directed towards setting out the various requirements which arise in the evaluation of x‐ray patterns. The second part of the paper describes a microdensitometer designed to conform with some of these requirements.