There are many types and forms of metallographic microscopes in metallographic microscopes, including desktop, vertical, and horizontal types. But its basic structure is basically the same, usually consisting of three systems: optical system, lighting system and mechanical system. Some microscopes also have photographing devices, polarized light attachments, etc. to expand the function of the microscope. The structure of the domestic 4X type desktop metallurgical microscope is shown in Fig. 2. This type of microscope is very versatile due to its compact structure, simple operation, and wide application.

The use of metallurgical microscope 1. According to the required magnification of the observation sample, the correct matching of the objective lens and eyepiece, respectively, mounted on the lens holder and the eyepiece tube.

2. Adjust the alignment of the center of the stage and the center of the objective lens. Place the prepared sample in the center of the stage. The observation surface of the sample should face down.

3. Insert the light bulb of the microscope on the low voltage transformer (6~8V), and then insert the transformer plug into the 220V power socket to make the light bulb shine.

4. Turn the coarse focusing handwheel to lower the stage so that the observation surface of the sample is close to the objective lens; then turn the coarse focus knob in the reverse direction to raise the stage so that the fuzzy image can be seen in the eyepiece; Focus the handwheel until the image is clearest.

5. Appropriately adjust the aperture diaphragm and field diaphragm, select the appropriate filter lens to obtain the ideal object image.

6. Move the stage from side to side and left and right to observe different parts of the specimen so that the most representative microstructure can be analyzed and found.

7. After the observation is completed, the power should be cut off in order to prolong the service life of the lamp.

8, after the end of the experiment, should carefully remove the objective lens and eyepiece, and check for dust and other pollution, if any pollution, it should be promptly wipe clean with lens paper clean, and then put in a desiccator to save in order to prevent moisture mildew . The microscope should also be covered with a dust cover at any time.