Calibration Overview
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Magnification Calibration

The 10 x 50,000x Pitch Standard for Scanning Electron Microscopy

geller mrs-3 mrs3 magnification calibration standard
Details of Traceability to NIST, NPL or ISO 9000 Compliance


  • 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 100nm
  • 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 100nm CrO2 and Cr on quartz
  • Particle Size Counting - series of circles, squares and rectangles for calibration confirmation

Pattern Design

The MRS-3 is fabricated using the high accuracy direct write electron beam manufacturing equipment. The pattern is anti-reflective chromium (30nm Cr2O over 70nm 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-3 has groups of nested squares with pitches of 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 2µm pitch allows calibrations up to 50,000x.


The overall size of the MRS-3 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-3.

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 is a choice of two optional retainers:
  • #614-5 – SEM/R which is 25mm in diameter with a thickness of 3mm. Can be used for optical transmitted light, SEM, 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.

The #614-5 SEM/R protective retainer can be mounted on a 25mm pin stub as an option (order #614-62)or a Ø25 x 10mm x M4 cylinder mount (order #614-63) as an option.

A special version of the MRS-3 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 pitch pattern was ±0.25µm and ±0.1µm for the 50µm and 2µm patterns. It goes without saying that these reported results from NPL are highly conservative. Our customers have also sent MRS-3's to NIST. The NIST data shows better accuracy than NPL reports.

Certification report

The certification is done following ISO guidelines. Each MRS-3 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.

MRS-3 is more radiation resistant. (It handles about 10x the electron beam current density and provides higher scanning electron microscopy imaging contrast, even at 500eV. Patterns have been added to help calibrate particle size counting systems and determine the spatial resolution in video and surface chemical imaging systems. Highest accuracy equipment used.
Measurements in the X-Y Plane can be certified to NIST and NPL standards. Z plane measurements are traceable to a NIST standard only.

NIST = National Institute of Standards and Technology, USA

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

Ordering Information

Prod # Description Unit Price Order / Quote
Magnification Reference Standards
614-1 MRS-3 Reference Standard, X, Not Traceable, without Protective Retainer, Unmounted each $490.00
614-2 MRS-3 Reference Standard, X-Y, Traceable, without Protective Retainer, Unmounted each 1500.00
614-3 MRS-3 Reference Standard, X-Y-Z, Traceable, without Protective Retainer, Unmounted each 1800.00
Retainer for MRS-3
614-5 Protective Retainer for MRS-3/4, SEM, 1" dia. x 0.125" (25.4 x 3.18mm) with clear hole for transmission measurements. Standard recessed 0.02" (0.5mm), aluminum, Ni plated each 100.00
614-7 Adapter MRS-3/4 only, specify AMRAY, Leica each 100.00
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 100.00
614-61A Modify the MRS-3 to 3mm diameter x 0.5mm thickness to fit into a TEM style holder. For use only in secondary or backscattered electron mode, not transmitted. each 350.00
Specimen Mount
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 125.00
614-63 Mounting MRS-3/4 Retainer on Hitachi Ø25x10mmxM4 Cylinder Mount, for #614-5 only each 125.00
Cleaning and Re-calibration Service
614-71A MRS-3 X-Y/R Cleaning, Re-coating and Re-calibration each 1000.00
614-72A MRS-3 X-Y-Z/R Cleaning, Re-coating and Re-calibration each 1300.00
614-73 MRS-3/4/5 Cleaning and Re-coating only each 200.00

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