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diagram of microscope

How to Adjust a Dissecting Microscope

1. Make sure to begin with the microscope on the lowest magnification power (for example, 7x instead of 10x).

2. Place the sample on the stage.

3. Turn the light on. The light will most likely be located in the microscope, under the stage. If it is not, then your microscope uses an external light source. In this case, you should point the light at the sample, but keep the light as far away from the sample as possible to avoid overheating it.

4. Adjust the eyepiece so that they are the proper distance apart for you to see through them. This is done by GENTLY pulling them apart or pushing them together.

5. Direct student to look through the eyepiece to see if he/she can see the sample at all. Try moving it around slightly to get a better view. Also make sure to adjust the amount of light coming through your sample. It is best to use as little light as you possibly can to give better contrast of the sample (which will make it easier to see). If the light is too bright or too dark then you might not be able to see the sample very well.

6. Now slowly adjust the coarse adjustment while looking at your sample through the eyepiece. You should do this my starting with the upper part of the microscope (called the objective) as close to the sample as possible without touching it. Use the coarse adjustment knob to move the objective AWAY from the sample until it comes into focus. As you slowly turn the adjustment knob you will notice the image will get clearer and clearer. Stop adjusting when the sample is the clearest.

7. After the sample has been completely focused with the coarse adjustment the microscope can be turned up to a higher magnification power by turning the magnification control knob. Make sure to only go turn the knob up by one magnification at a time and then stop to look through the eyepiece.

Some Rules to Follow When Using a Microscope

Direct students to:

1. Be careful and gentle every time they use a microscope. Microscopes are delicate and expensive.

2. If any kind of material from your sample (such as water) gets onto any part of the microscope make sure to wipe it off immediately and carefully.

3. When carrying a microscope, always hold it underneath the stage with one hand and hold the arm of it with the other hand. Never carry it by the cord or without supporting the stage area.

4. Always adjust the coarse adjustment with the microscope on lowest power. This way it will make it easier to focus on the sample and not damage any parts of the microscope.

 

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