Use and Maintenance of Biological Microscope (Oil Mirror)
Purpose requirements
Familiar with the structure of biological microscopes, proficient in the use of microscopes, especially the use and maintenance of oil lenses.
Experimental content
1. The structure of a biological microscope is composed of a mechanical support and adjustment system and an optical amplification system.
(1) The mechanical system components of a biological microscope are the skeleton of the entire microscope, which serves as the base for installing an optical amplification system. The mechanical components of a microscope include a mirror base, mirror wedge, mirror barrel, rotating disc, adjuster, stage, thruster, condenser, aperture, power supply adjustment, etc.
(2) The optical amplification system components of a biological microscope include an eyepiece, objective, condenser, electric light source, etc.
2. Usage and precautions for microscopes: The microscope structure is precise and must be used carefully. The following steps should be followed.
(1) Prepare to tightly grasp the buttocks of the mirror with your right hand, hold the mirror base with your left hand, and place the biological microscope on the experimental table steadily, in a position in front of your body that is slightly to the left, about 10cm away from the table. You can place a notebook or drawing paper on the right side.
(2) To adjust the light source, first minimize the current regulator family, plug in the power, turn on the power switch, and rotate the regulator to make the brightness from weak to strong, making it suitable for observation.
(3) Low power mirror observation positioning: Low power mirror has a larger field of view, making it easy to detect targets and determine the location of the examination. Place the specimen on the cutting table, move the thruster so that the observed specimen is directly below the objective lens, rotate the coarse adjustment screw to make the objective lens reach 5mm of the specimen, adjust the condenser to weaken the light, observe with the objective lens, and slowly raise the stage with the coarse adjustment screw until the field of view appears. Use the fine adjustment screw to make the field of view clear. Move it to the center of the field of view.
(4) High power lens observation, based on the positioning of low power lens observation, converts the high power objective lens. When converting the objective lens, it is necessary to avoid collision between the lens and the glass slide. Then observe through the eyepiece, adjust the brightness adaptation, slowly adjust the coarse adjustment screw to raise the stage until the object image appears, and then adjust the screw by sewing until the object image is clear. Move to the center of the field of view for observation or prepare to use a sleeve mirror for observation.
(5) Oil mirror observation, the magnification of the oil mirror is deleted, and only in this state can bacteria be observed better. The use of a mirror requires the addition of tar, as the lens of the mirror is very small. When light passes through the specimen and enters the air, due to different media densities, some light cannot enter the lens due to refraction, resulting in insufficient brightness of the field of view and unclear object images. Adding cedar oil (n=1.535) similar to the glass refractive string (n=1.52) between the specimen and the mirror avoids refraction and reflection of light, enhances the brightness of the field of view, and improves resolution. The working distance of an oil immersed objective (referring to the distance between the surface of the front lens of the objective and the object being tested) is within 0.2mm, so when using an oil immersed objective, special care should be taken to avoid accidentally focusing and crushing the specimen, which can also damage the objective. The following steps must be followed.
① Apply 1 drop of tar to the microscopic examination site on the specimen and place it in the center of the stage.
② Adjust the coarse screw and raise the stage to immerse the oil lens in cedar oil. At this point, the lens is almost in contact with the specimen.
③ Observe through the eyepiece, amplify the aperture or adjust the current to achieve appropriate brightness. Slowly adjust the coarse spiral to raise the cutting table, and if there is an object image, use a fine spiral (only allowed to be adjusted within 180 °) to adjust it until the object image is clear. If the sleeve lens has left the oil surface and still cannot see the object, the above operation must be repeated until the object is clear.
④ After observation, lower the loading table, rotate the rotating disc to offset the sleeve mirror, and first wipe off the mirror with mirror paper
Use cedar oil on your head and dip a little xylene in a piece of lens paper to remove any remaining oil stains on the lens. After rinsing, use again
Wipe off xylene with mirror paper.
⑤ Restore all components and turn off the power.
Lens. Return the biological microscope to the container or container
Maintenance of 3 microscopes
(1) Biological microscopes are valuable precision instruments that should be used with care and care, and should not be disassembled or played with.
(2) Keep the microscope clean and wipe all components with a soft cloth before and after use. Wipe each optical lens with lens wiping paper. After using the oil immersed lens, immediately use brown lens paper to remove the oil in one direction. Do not let the lens oil dry and cause the lens to become blurry.
(3) Avoid direct exposure to strong light on the microscope, and be careful not to let acids, alkalis, chloroform, etc. come into contact with the machine parts.
(4) If the microscope is not used for a long time, cover it with a plastic dust cover and place it in a mirror box or microscope cabinet, keeping the environment dry, cool, and ventilated.
