The monitoring of performance of an SEM in a multi-user facility is a difficult task as user feedback is generally not reliable. Regular quality control measurements must be undertaken using standard conditions to maintain research-quality products. The test specimens should also be available to the general user community to allow them to monitor their own skills against the reference images. The ready availability of these specimens also helps to eliminate problems related to user specimen preparation, as users can refer back to them when in doubt with respect to SEM performance.

Certified SEM imaging standards are expensive and cannot be provided routinely, particularly where a number of SEM are present. We have investigated a range of potential materials and preparations in search of a low cost, reliable and robust specimen for use in routine (day-to-day) quality control.