Continuing Education, Math -

Eyepiece Micrometer Calibration Chart for Nikon Microscopes

EYEPIECE MICROMETER CALIBRATION

Your straight-line 10mm Eyepiece Micrometer (Also known as an eyepiece reticle) looks like this:

Under the naked eye, the length of the ruled distance is 10mm.  As you switch between your objective lenses, the distance between each of the small divisions changes under different magnifications.  

Each small division is equal to the measurement below when your microscope is on the corresponding  objective.

Objective Power

Each small Division equals in microns

Each Small Division equals in mm

1x objective

100 um

0.100mm

2x objective

50 um

0.05mm

4x objective

25 um

0.025mm

10x objective

10 um

0.01mm

20x objective

5 um

0.005mm

40x objective

2.5um

0.0025mm

50x Objective

2um

0.002mm

60x Objective

1.67um

0.00167mm

100x Objective

1 um

0.001mm