The process of using an ordinary optical microscope is as follows
1. Preparation before microscopic examination
The room should be clean and dry, the experimental bench should be level, stable and vibration-free, and corrosive reagents should not be placed near the microscope. When taking out the microscope from the microscope cabinet or mirror box, hold the mirror arm tightly with your right hand, hold the mirror base with your left hand, take it out smoothly, place it on the tabletop of the experimental table, and place it in front of the left side of the operator, about 10cm away from the edge of the experimental table. The arms of the mirror are facing you and the lens barrel is facing forward. Drawing utensils are placed on the right side of the experimental table.
2. Adjust light source
If you need to use an external light source, you should use diffused natural light or soft lighting. Direct sunlight can cause damage to the observer's eyes. Rotate the converter so that the low-power lens is facing the light aperture, open the iridescent aperture on the condenser to the maximum, observe the brightness of the field of view in the eyepiece, and adjust the angle of the reflector to make the illumination the brightest and most uniform. A microscope with its own light source can adjust the intensity of the light by adjusting the current knob.
3. Installation of slides to be inspected
Make a temporary or permanent mount of the sample to be observed, place it on the stage, and fix it with a spring clip, with the cover glass side facing up. Move the pusher and adjust the sample to be inspected to the center of the light hole.
4. Low magnification observation
Align the low-magnification lens with the light aperture, slowly turn the coarse focus screw, and adjust the distance between the objective lens and the mounting film to the shortest distance. Be careful not to crush the coverslip. Observe through the eyepiece, while slowly adjusting with the coarse focus screw until the object image appears, then fine-tune with the fine focus screw, and simultaneously adjust the brightness of the light source and the size of the iridescent aperture to achieve the clearest object image. And use the propeller to move the part that needs further magnification for observation to the center of the field of view. If binoculars are used, the distance between the binoculars should be adjusted before observation so that the fields of view of the two eyes merge.
5. High magnification observation
Turn the converter, select a higher magnification objective lens, and use the fine focus screw to adjust the focus until the object image is clear.
6． Oil lens observation
The working distance of the oil immersion objective lens (referring to the distance between the surface of the front lens of the objective lens and the object being inspected) is very short, generally within 0.2 mm, and the oil immersion objective lens of the general optical microscope does not have a "spring device", so the oil immersion objective lens is used When doing this, the focusing speed must be slowed down to avoid crushing the glass and damaging the objective lens.
(1) Find the observation target under low magnification, gradually magnify under medium and high magnification, place the area to be observed in the center of the field of view, adjust the light source and iridescent aperture to maximize the light passing through the condenser.
(2) Turn the coarse focus screw, turn the lens barrel up (or lower the stage) by about 2 cm, and add a small drop of cedar oil to the microscopic examination part of the slide.
(3) Slowly turn the coarse focus screw back and observe from the side until the oil lens is immersed in the oil droplets and the lens is almost in contact with the specimen.
(4) Observe through the eyepiece and fine-tune with the fine focus screw until the object image is clear.
(5) After the microscopic examination, rotate the lens away from the glass and clean the lens immediately. Generally, first use lens cleaning paper to wipe off the cedar oil drops on the lens. Then use lens cleaning paper dipped in a little ether-alcohol mixture (2:3) to wipe off the remaining oil stains, and finally wipe it clean with clean lens cleaning paper (pay attention to wiping in one direction).
7． Restoration microscope
Turn off the built-in light source and unplug it, or position the reflector perpendicular to the condenser. Rotate the nosepiece so that the objective lens is in a figure-eight position opposite to the light aperture. Then adjust the distance between the lens tube and the stage as close as possible and lower the condenser. Put on the dust cover and put the microscope back into the cabinet or mirror box.
