How to use the Biological Microscope 100 oil objective in the correct way
The specific steps are as follows:
(1) After first finding the specimen with a low-magnification objective lens, switch to a high-magnification objective lens for observation, move the specimen to the center of the field of view, place the aperture at its maximum position, and raise the lens tube by about 1.5 cm (or lower the stage by 1.5 cm) ) to rotate the objective lens away from the optical axis.
(2) Remove the specimen piece, drop 1 or 2 drops of cedar oil on the upper lens plane of the condenser, and then put the specimen piece back to its original position so that the bottom of the slide is in close contact with the cedar oil to prevent air saturation in the oil. But in normal operation, this step can be omitted.
(3) Drop 1 drop of cedar oil on the cover glass or on the part of the smear specimen required to be observed, switch the oil lens to the optical axis, and adjust the coarse focusing screw carefully to lower the lens slowly and carefully. Observe the distance between the front end of the oil glass and the specimen. When the front end of the oil glass begins to touch the oil droplets, it will stop falling. This operation must be done very carefully to prevent the oil lens from crushing the specimen and damaging the oil lens.
(4) Use your left eye to observe through the eyepiece, and use your right hand to adjust the fine-adjustment screw to slowly focus the lens to the correct working distance until you can see the specimen clearly. Please note: Do not make a mistake with the coarse and fine focusing screws. The cover glass should be thin. If it is too thick, it will not be able to focus, otherwise it will easily crush the specimen and damage the lens.
(5) Adjust the size of the aperture so that the numerical aperture of the condenser matches the oil lens to obtain a clear image. '
(6) After observation, clean up in time. First, raise the oil lens to a distance of 1.5 cm from the specimen, turn the oil lens away from the optical axis, gently absorb the oil on the oil lens with dry lens cleaning paper, and then wipe both sides with lens cleaning paper soaked in xylene. times, and finally wipe it gently with clean lens paper 2 or 3 times. Use the same method to wipe away the oil droplets on the condenser. The cedar oil on the specimen piece can be wiped clean with the paper pulling method, that is, use a small piece of lens cleaning paper to cover the oil droplets on the specimen piece, then drop some xylene on the paper, and pull the paper out while it is wet, and do this for 3 consecutive times. 4 times, it can be wiped clean without damaging the smear specimen. Precautions for using oil lens:
1) When the use of the oil lens is temporarily interrupted, the lens barrel should be raised to rotate the objective lens away from the optical axis to prevent the specimen piece from being pushed down by the lens barrel and damage to the condenser and oil lens.
2) After use, clean off the cedar oil in time, because cedar oil easily sticks to dust in the air, and the lens may be worn when scrubbing after dust sticking. In addition, cedar oil is not easy to clean after it dries in the air. Over time, it will cause corrosion, dust accumulation, mildew, fogging and other hazards to the glued joints of the lens, so it must be wiped off promptly and thoroughly.
3) When using an oil lens, it is generally not necessary to adjust the focus at the same height, because the focus adjustment at the same height is only suitable for the original objective lens of each microscope. If the thickness of the specimen is too thick, the oil lens may be changed when adjusting the focus at the same height. Touch the slide.
In addition to cedar oil as the oil immersion medium, water can also be used as the medium, which is suitable for observing living specimens in water. The operation method is basically the same as above.
