Measuring Objects Seen with a Light Microscope

Question 1

What is an eyepiece gratitule?

Answer 1

Transparent measuring device placed in microscope eyepiece, acting as ruler when viewing an object

Question 2

What is a stage gratitule?

Answer 2

Small scale, precise measuring device placed on microscope stage, used to calibrate eyepiece division values at different magnifications

Question 3

What is a stage graticule only used for?

Answer 3

Calibrate eyepiece graticule at different magnifications

Question 4

How big is a stage gratucule?

Answer 4

1mm (100 divisions)

Question 5

How do you calibrate the eyepiece graticule?

Answer 5

1. Insert EP graticule into microscope eyepiece
2. Place S graticule on microscope stage and bring into focus using low power (×4) OL
3. Align EP and S graticule, checking one eyepiece division values at this magnification and calculate 1epu
4. Use different OL and focus on S graticule
5. Align again and calculate 1epu