Why Oil Objectives on Optical Microscopes Have the Highest Resolution
Optical magnification system components The optical system of the biological microscope includes eyepieces, objective lenses, condensers, electric light sources, etc.
2. How to use the microscope and precautions The structure of the microscope is precise, so you must be careful when using it, and follow the steps below.
(1) Prepare to hold the buttocks of the mirror tightly with the right hand, hold the mirror base with the left hand, and place the biological microscope on the laboratory table almost stably, at a position to the left in front of the body, about 10cm away from the table sash, and place a notebook or drawing paper on the right side.
(2) To adjust the light source, first set the current regulator to the minimum, plug in the power supply, turn on the power switch, and rotate the regulator to make the brightness from weak to strong. suitable for observation.
(3) Observation and positioning of the low-magnification lens The field of view of the low-power lens is larger, and it is easy to find the target and determine the position of the inspection. Place the specimen on the cutting stage, move the propeller so that the specimen to be observed is directly below the objective lens, turn the coarse adjustment screw to bring the objective lens to the o5mm of the specimen, adjust the condenser to weaken the light, observe with the eyepiece and at the same time use the coarse adjustment screw to slowly raise the stage. Until the field of view appears *, then use the fine adjustment screw to make the field of view clear. Move it to the center of the field of view.
Structure diagram of biological microscope
(4) For high-power lens observation, switch to high-power objective lens on the basis of low-power lens observation and positioning, and avoid collision between lens and slide when switching objective lens. Then observe from the eyepiece, adjust the light to adapt, slowly adjust the coarse adjustment screw to raise the stage until the object image appears, and then use the sewing adjustment screw to adjust the object image to be clear, move to the center of the field of view for observation or prepare to observe with the sleeve mirror.
(5) Oil immersion observation, the magnification of the oil immersion immersion is double, and only in this state can the bacteria be observed better. It is necessary to add cedar oil to use the mirror. This is because the lens of the oil mirror is very small. When the light passes through the specimen and enters the air, due to the different density of the medium, part of the light cannot enter the lens due to refraction, and the brightness of the field of view is not enough, and the object image is not clear. Cedar oil (n=1.535), which is similar to the refractive series of glass (n=1.52), is added between the specimen sheet and the mirror, which avoids the refraction and reflection of light, enhances the brightness of the field of view, and improves the resolution. The working distance of the oil immersion objective lens (referring to the distance between the surface of the objective lens front lens and the object under inspection) is in o. 2mm, so be careful when using the oil immersion immersion immersion immersion immersion immersion immersion immersion immersion immersion immersion immersion immersion immersion immersion immersion lens to avoid crushing the specimen inadvertently. Also damage the objective lens. The following steps must be followed.
① Put 1 drop of cedar oil on the microscopic examination part of the specimen, and put it in the center of the stage.
②Adjust the coarse screw, raise the stage, and immerse the oil lens in the cedar oil. At this point the lens is almost in contact with the specimen.
③ Observe from the eyepiece, enlarge the aperture or adjust the current to make the brightness appropriate. Slowly adjust the thick screw to raise the cutting table. When the object image appears, use the thin screw (only allowed to adjust within 180°) to adjust until the object image is clearest. If the sleeve lens has left the oil surface and still cannot see the object image, repeat the above operation until the object image is clearest.
④ After observation, lower the objective stage, turn the rotating disk to make the sleeve mirror deflected, and wipe off the mirror with the mirror paper first.
Cedar oil on the head, and then dipped in a little xylene with a probe paper to wipe off the remaining oil on the lens, and then use it again
Wipe off xylene with lens tissue.
