Microscope Calibration

Microscope calibration is important to ensure that the same sample, when assessed with different microscopes, will yield the same results. Even two identical microscopes can have slightly different magnification factors when not calibrated. The scale on the eyepiece reticle does not have units and the values change at different magnifications. Therefore, it is important to calibrate the eyepiece reticle before taking measurements to ensure that the microscope will output accurate and valid information.

The field calibration team at LTI Metrology will calibrate microscope reticles onsite for customers at their facilities. Microscope calibration is A2LA accredited and NIST traceable. Calibration Certificates include accreditation and traceability information, in addition to “as found” and “as left” data and detailed calibration results.

The Calibration Process

The size of objects in the microscope’s field of view differs at each magnification, so the actual diameters of these fields of view need to be calculated through calibration. The process of microscope calibration is a comparison of the grid on the eyepiece reticle with a stage micrometer showing units in millimeters or micrometers to validate the scale. When calibrating, the stage micrometer is lined up with the grid on the reticle, then the number of divisions on the microscope are counted per millimeter or micrometer on the staged micrometer. The number of divisions will change as the magnification changes.

Microscope Calibration Capabilities

• Calibrating most microscope models
• NIST traceability
• A2LA accreditation to ANSI/ISO/IEC 17025