A microscope stage micrometer is used to calibrate an eyepiece reticle. The stage micrometer is a glass slide that has a ruler printed on it. Stage micrometers can be NIST certified for exact points.
The above is an example of the 1" and 25mm stage micrometer. The top line is what is printed on the stage micrometer. The two lines below explain the divisions on the stage micrometer.Because each microscope has a slightly different magnification factor, calibrating the eyepiece reticle with a stage micrometer will help you to ensure that your measurements are accurate. Learn more about microscope calibration here.
