1. Measuring cells

2. A stage micrometer has 100 divisions so each division is 0.01mm wide
Measuring Cells
The eyepiece graticule is a scale that fits into the eyepiece of a microscope that can be used to measure microscopic objects. It’s size does not change when you magnify an image.
The stage micrometer is a small ruler etched onto a glass slide that has a known length of 1mm. It’s size in the field of view increases as magnification is increased.
1mm
A stage micrometer has 100 divisions so each division is 0.01mm wide

3. EYEPIECE GRATICULE

4. Calibrating your microscope
Place a stage micrometer onto the stage of the light microscope
Focus the microscope so that both the stage micrometer and eyepiece graticule are in clear view
Count the number of divisions of the eyepiece graticule that represents the total length of the stage micrometer (X)
Calculate the actual length (A) represented by one division of the eyepiece graticule
5. The actual length represented by the whole length of the eyepiece graticule (W) = A x number of divisions on the graticule

5. Measuring cells Choose a prepared slide
Using the objective lens that you have calibrated, measure the length of your specimen using the eyepiece graticule
Work out the actual length of the specimen