Calibration Overview
SEM Calibration Overview Page
SEM Magnification Calibration
MRS-3 Reference Standard
MRS-6 Reference Standard

SEM Magnification Standard
and Stage Micrometer MRS-4

The 10x to 200,000x standard for Scanning Electron Microscopy
with 1/2, 1, 2, 50 and 500µm pitch patterns and X & Y Micro-ruler

mrs-4 mrs4 geller reference standard

Selected MRS-4 Patterns in Greater Detail


  • Electron microscopy - SEM, in both SE and BSE mode, SEM/FIB and TEM (with special version)
  • Scanning Microscopies and Profilometry - STM, AFM, the pattern height is 70nm
  • Optical Microscopy - transmitted, reflected, bright/dark field, differential contrast and confocal
  • Chemical mapping - EDS, WDS, XRF, XPS, Auger and others. The pattern is fabricated using 30nm CrO2 over 40nm Cr on quartz
  • Particle Size Counting - series of circles, squares & rectangles for calibration confirmation

Pattern Design

The fifth generation MRS-4.2 is fabricated using the high accuracy direct write electron beam manufacturing equipment. The pattern is anti-reflective chromium (30nm Cr2O over 40nm Cr) on quartz. Imaging in both secondary and back scattered mode is very high. The pattern is coated with a proprietary conductive material which allows for SEM imaging at any accelerating voltage.

Geometric design

The MRS-4 has groups of nested squares with pitches of 1/2µm, 1µm, 2µm, 50µm and 500µm. The largest pattern has an overall dimension of 8mm square with lines and spaces of 250µm. This can be used to check magnifications between 10 - 100x. The 50µm pitch patterns are useful from 100 - 1000x magnifications. The 2, 1 and 1/2µm pitch patterns allow calibrations up to 200,000x. Incorporated into the standard are X & Y rulers with 6mm length with 1µm increments.


The overall size of the MRS-4 is approx. 9 x 9 x 2.3mm. Since the standard is made on quartz, it easily chips. We highly recommend ordering the optional protective retainers for the MRS-4.

MRS4 - MRS-4 with aluminum retainer   Optical Microscope Adapter OM/R
Optional Protective Retainer 614-5 and Optional Pin Stub Mounting 614-62   Optical Microscope Adapter OM/R 614-6

The standard is mounted in the retainers using an ultra high vacuum compatible, conductive silver epoxy. There are two retainers available:

  • #614-5 – SEM/R which is 25mm in diameter with a thickness of 3mm. Can be used for optical transmitted light , SE, FIB and SPM applications. Material is aluminum, Ni plated. Standard recessed: 0.5mm
  • #614-6 – OM/R which is the 44.5 x 25.4 x 3.2mm optical microscope adapter, fits easily on light microscopes. Material is aluminum. Standard is slightly recessed; 0.13mm.

For the #614-5 SEM/R protective retainer can be mounted on a 25mm pin stub as an option (order #614-62).

A special version of the MRS-4 is available for (S)TEM with a 3mm diameter and a thickness and a thickness of 500µm. This will only show the central features and can be viewed with secondary and backscattered electrons, not with transmitted electrons.


Measurements by the NPL in the UK (counterpart of NIST) have demonstrated that the accuracy of the 500µm was ±0.25µm, and ± 0.1µm for the 50µm and 2µm patterns. The 1µm and 1/2µm patterns have an accuracy of ±0.04µm.

Certification report

The certification is done following ISO guidelines. Each MRS-4 has a unique serial number engraved on the standard. Certification includes the serial number, certification date, operator, instrumentation used, actual pattern measurements and measure of accuracy.

NIST = National Institute of Standards and Technology, USA

NPL = National Physical Laboratories, UK (counterpart of NIST)

Sample Certificate for MRS-4 (301KB PDF)
Details of Traceability to NIST, NPL or ISO 9000 Compliance

Ordering Information

All standards are carbon coated. Can be supplied uncoated by specific request.

Prod # Description Unit Price Order / Quote
Magnification Reference Standards
614-821 MRS-4 Reference Standard, X, Not Traceable, without Protective Retainer, Unmounted each $1150.00
614-822 MRS-4 Reference Standard, X-Y, Traceable, without Protective Retainer, Unmounted each 2415.00
614-823 MRS-4 Reference Standard, X-Y-Z, Traceable, without Protective Retainer, Unmounted each 2760.00
Retainer for MRS-4
614-5 Protective Retainer for MRS-3/4, SEM, 1" x 0.125" (25.4 x 3.18mm) with clear hole for transmission measurements. Standard recessed 0.02" (0.5mm) each 130.00
614-7 Adapter MRS-3/4 only, specify AMRAY, Leica each 130.00
614-6 Optical Microscope Adapter OM/R 1.75" x 1" x 0.125" thick (44.5 x 25.4 x 3.2mm) with clear hole for transmission measurements. Standard slightly recessed 0.005" (0.13mm), aluminum, Ni plated each 130.00
614-61B Modify the MRS-4 to 3mm diameter x 0.5mm thickness to fit into a TEM style holder. For use only in secondary or backscattered mode, not transmitted. each 400.00
Specimen Mounts
614-62 Mounting MRS-3/4 Retainer on 1" (25.4mm) Pin Stub with a 1/8" (3.2mm) pin, for #614-5 only each 130.00
614-63 Mounting MRS-3/4 Retainer on Hitachi Ø25x10mmxM4 Cylinder Mount, for #614-5 only each 130.00
Cleaning and Re-calibration Service
614-71B MRS-4 X-Y/R Cleaning, Re-coating and Re-calibration each 1725.00
614-72B MRS-4 X-Y-Z/R Cleaning, Re-coating and Re-calibration each 2070.00
614-73 MRS-3/4/5 Cleaning and Re-coating only each 230.00

To avoid contamination of your MRS Standard, we recommend storing the standard under vacuum. For MRS Standards mounted on pin stubs the PELCO® SEM Sample Stub Vacuum Desiccator would be ideal.

Prod # Description Unit Price Order / Quote
16179 PELCO® SEM Sample Stub Vacuum Desiccator each $267.50