Using a Graticule and Stage Micrometer in Measuring Cell Size at Both Low and High Powers

An eyepiece graticule is a glass disc with a scale etched on it, which is placed on the eyepiece of a light microscope

The eyepiece must be calibrated for each objective lens used. A stage micrometer, with a known lenght (1cm/mm), is placed on teh stage and used. It should be superimposed (side-by-side). The total lenght of the eyepiece graticule scale can be measured and the lenght of each SEU (small eyepiec unit) calculated.