X-ray film ruler

An X-ray film ruler is a reusable device used in radiology to add permanent measurement markings directly onto X-ray film. It allows clinicians to measure anatomical structures or treatment fields by placing a graduated scale over the exposed film, with the markings appearing on the final image due to the non-translucent graduations on an otherwise translucent base.

These devices are typically supplied as reusable tools made from X-ray translucent materials such as plastic, with opaque graduations that appear on the film after exposure. They are not medicated, do not contain drugs, and are intended for repeated use in imaging departments to support accurate documentation and analysis of radiographic images.