Calibration of compound microscopes at low magnifications, stereo microscopes and measurement of fields of view require a longer scale than those traditionally available. This stage micrometer has a high accuracy scale of 20mm length, which is sub-divided into 10µm divisions. The scale is produced as a vacuum deposited chrome image on glass, with a cover glass cemented on top. This is mounted in a stainless steel slide mount and is supplied in a polished wooden case.