We are majoring in materials science, and metallographic analysis experimental courses are essential. There are many equipment in the metallographic laboratory, such as metallographic cutting, inlaying, polishing, optical metallographic microscope, etc. These equipment have a set of operating procedures when used. Relatively speaking, the cutting, inlaying, and polishing equipment feel relatively solid and durable. For students who are just starting to learn operations, they are more daring to operate by hand, Looking at the metallographic microscope alone gave me a feeling of being at a loss. Firstly, the microscope feels like a more delicate and delicate device, fearing that any mishandling may damage it.

In fact, metallographic microscopes are also relatively durable equipment, with very precise optical components. However, after mastering the correct operating methods, they are no different from other equipment and can be easily used. Moreover, current optical microscopy equipment is made with precision technology, with excellent quality and comprehensive protective measures, which can basically avoid misoperation. More importantly, students should familiarize themselves with the operating steps before operating the machine, Once you have a clear understanding, you can start operating on the computer. Below, we will introduce the operating steps of the commonly used upright metallographic microscope in our laboratory:

1、 Equipment placement

As it is a Optical instrument, there is a requirement for light. It is necessary to choose a place with sufficient light, and the position near the window is more appropriate. In addition, optical lenses also have requirements for environmental cleanliness and require the laboratory to maintain cleanliness. Another thing is that the workbench must be stable. Generally, placing the metallographic microscope on the left side of the observer and maintaining a distance of 4cm-8cm from the table edge is more suitable.

2、 Cleaning of equipment
Firstly, conduct an appearance inspection of the metallographic microscope. Wipe the mechanical part of the body with a clean soft cloth, and wipe the lens with lens wiping paper. If any glue or dirt is found, a small amount of xylene can be used to clean. Clean the lens lightly and use professional lens wiping paper for cleaning.
3、 Lens alignment
Raise the lens tube to a distance of 1cm-2cm from the stage, and align the low-power lens with the light hole. Adjust the aperture and reflector. When the light is strong, use a flat mirror. When the light is weak, use a concave mirror. The reflector should be rotated with both hands.
If using a microscope with a light source, it is necessary to adjust the brightness knob.
4、 Placement of specimens
Place the specimen to be observed on the stage, ensuring that the side to be observed is facing upwards. Rotate the knob of the platform shifter to align the specimen to be observed with the center of the aperture.

5、 Focusing of the lens
When focusing, first rotate the coarse adjustment knob to slowly lower the lens barrel. Carefully observe from the side until the objective lens is close to the specimen, then observe from the eyepiece. Rotate the coarse adjustment knob with the right hand to lift the lens barrel until the specimen image is clear and stop. Then, use the fine adjustment knob to adjust back to clarity.
Using binocular eyepieces, the binoculars can be relatively shifted to adapt to the distance between the operator's eyes. If there is a difference in the visibility of the observer's eyes, the visibility adjustment circle can be used to adjust.
Attention:
Understand the critical value of object distance, and when the lens tube descends, observe the distance between the lens tube and the specimen from the side; Do not focus directly under a high-power lens.
6、 Observation of specimens
First, use a low-power microscope to identify the target and determine the area to be observed, then switch to a high-power microscope and slightly adjust the fine focusing knob to make the object clear and move the center of the specimen's field of view. A clear map image will appear on the computer monitor. Record according to the observation results.
During observation, the specimen should be moved in a certain direction until the entire specimen is observed, so as not to miss or repeat the examination.
Adjustment of light intensity: Generally, for stained specimens, the light should be stronger; Unstained or colorless specimens should have weaker light. For low magnification mirrors, the light should be weak, while for high magnification mirrors, the light should be strong.

Attention:
1. When using a high-power lens, it is prohibited to use a coarse focusing knob, as it can easily crush the specimen and damage the lens.
2. When rotating the objective lens converter, it is prohibited to directly push the objective lens with your fingers to prevent the optical axis of the objective lens from tilting and damage to the converter thread due to uneven force.

7、 Operation completed
After observation, remove the specimen and rotate the converter to tilt the V-shaped lens to both sides. The reflector should be upright, the tube should be lowered, cleaned, and then the lens cover should be put on.
If you are using a microscope with a light source, you need to turn the brightness down and then turn off the power button to prevent excessive current from burning out the light source during the next startup.
The above is a reference for students. Due to some differences in the metallographic microscopes of different manufacturers, please carefully read their instructions before operating. Be bold and careful, remember the precautions, and there will be basically no problems in operation.