SEM Low-Mag Calibration Disc

This comes mounted on a variety of standard mounts, or it can be mounted on a custom mount. The original scale was produced on a 15mm diameter glass disc as an inset on a rectangular microscope slide. The SEM Low‐magnification calibration disc is reproduced on a 1/8" nickel‐plated copper disc from this master. The scale is 1mm long with 100 markings, subdivided to 0.01mm and highlighted every fifth and tenth line. Selected intervals on the original stage micrometer have been measured using a traveling microscope. The movement of the microscope was measured by means of a helium‐neon laser interferometer. The wavelength of the laser has been determined by the reference of the International Krypton‐86 Standard. The distance between the lines was measured along the longitudinal axis of the scale.

Accuracy: The uncertainty of each length interval quoted is estimated to be less than plus or minus 0.0005mm.

Reference: These measurements were made at the National Physical Laboratory, Teddington, Middlesex, England. Test No. 08075 S/ML62‐199, dated July 6, 1979.