4How to use it1. CalibrateCalibration slide (0.01mm)
52. Set the microscope to low power and focus on the lines engraved on the surface of the calibration slide.
63. count the number of lines The total number of eyepiece lines (X)The total number of calibration slide lines (Y)X=38 linesY=10 linesnote that the little lines mark off half spaces and that the first line is not counted because is shows the zero mark
74. Calculate how much each line of the eyepiece measures. In step 3, 10/38x10μm=2.63μm
137. Now you can use the microscope to observe and measure things. Note that if you change microscopes, the calibration process must be done again for each of the objective lenses that you are using. Why? Because the magnification is different on different microscopes. To save time, only calibrate the eyepiece for the objective lenses that you will be using.
14More examples:A tomato cell's nucleus seen at high power. How big is the nucleus?
15An onion skin at high power. How big is a typical nucleus?
16A banana cell at high power. How big are the starch grains?