How to correctly utilize the 100 oil lens biological microscope
(1) After 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 the maximum position, raise the lens barrel by about 1.5 cm (or lower the stage by 1.5 cm), and rotate the objective lens away from the optical axis.
(2) Remove the specimen sheet, drop 1 or 2 drops of cedar oil on the lens plane at the upper end of the condenser, and then put the specimen sheet back to its original position so that the bottom of the slide glass is in close contact with the cedar oil to prevent gas 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 the part required to be observed on the smear specimen, switch the oil immersion lens to the optical axis, adjust the coarse focusing screw carefully to make the lens drop slowly, carefully observe the distance between the front end of the oil immersion lens and the specimen, and stop falling when the front end of the oil immersion lens touches the oil drop. This operation process must be very careful to prevent the oil lens from crushing the specimen sheet and damaging the oil lens from accidents.
(4) Use the left eye to observe from the eyepiece, and use the right hand to adjust the fine-focus screw, so that the lens can be slowly adjusted to the correct working distance to see the specimen image clearly. Please note: Do not mistake the coarse and fine focus helixes. 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 diaphragm so that the numerical aperture of the condenser mirror matches that of the oil mirror to obtain a clear image. '
(6) After the observation, do a good job of cleaning 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 a dry lens cleaning paper, then wipe it twice with a lens cleaning paper soaked in xylene, and finally use
Wipe clean lens tissue 2 or 3 times. The oil droplets on the condenser are wiped off in the same way. The cedar oil on the specimen can be wiped clean by pulling paper, that is, cover the oil drop on the specimen with a small piece of lens cleaning paper, then drop some xylene on the paper, and pull the paper out while it is wet. Precautions for using oil mirrors:
(1) When temporarily interrupting the use of the oil lens, the lens barrel should be raised to make the objective lens turn away from the optical axis, so as to prevent the accident that the lens barrel slides down and crushes the specimen sheet, damages the condenser lens and the oil lens.
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(2) After use, wash off the cedar oil in time, because cedar oil is easy to stick to dust in the air, and the lens may be worn when scrubbing after sticking to dust. In addition, cedar oil is not easy to wipe off after it is air-dried, and it will corrode, accumulate dust and
Mildew, fog and other hazards occur, so it must be cleaned in time and thoroughly.
(3) When using an oil lens, generally do not perform the same-height focusing operation, because the same-height focusing is only applicable to the original objective lens of each microscope. If the thickness of the specimen is too thick, when performing the same-height focusing, the oil lens may touch the glass slide.
In addition to cedar oil as oil immersion medium, water can also be used as medium, which is suitable for observing living specimens in water, and the operation method is basically the same as above.
