Operational Specifications for Optical Microscopes
1. Preparation before microscope examination
The room should be clean and dry, the benchtop should be level, stable and free of vibration, and no corrosive reagents should be placed near the microscope. When taking out the microscope from the microscope cabinet or mirror box, hold the mirror arm firmly with your right hand, hold the mirror base with your left hand, take it out smoothly, place it on the tabletop of the laboratory table, and place it in front of the left of the operator, about 10cm away from the edge of the laboratory table. Arms facing you, barrel facing forward. The drawing utensils are placed on the right side of the laboratory bench.
2. Adjust the light source If you need to use an external light source, it is advisable to use scattered natural light or soft light. Direct sunlight can damage the observer's eyes.
① Turn the converter so that the low-magnification objective lens is aligned with the light hole. Note that a distance of 2 cm should be kept between the front end of the objective lens and the stage.
② Align a larger aperture with the light hole. The left eye is fixed in the eyepiece, and the right eye is opened, which is convenient for observing and drawing in the future. Turn the mirror and see the bright view.
3. Low magnification observation
1) Put the glass slide to be observed on the stage, press it with the pressure clamp, and the specimen should face the light hole.
2) Turn the coarse quasi-focus screw to lower the lens barrel slowly until the objective lens is close to the glass slide. Keep your eye on the objective so that the objective does not touch the specimen slide.
3) Look into the eyepiece with the left eye, and at the same time turn the coarse focus screw in the opposite direction to make the lens barrel rise slowly until the object image can be seen clearly. Then turn the fine focus screw slightly to make the object image clearer.
4. Observation with high magnification lens
Turn the converter to select a higher multiple objective lens, and adjust the focal length with the fine focus screw until the object image is clear.
5. Oil immersion 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 under inspection) 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 , the focusing speed must be slowed down to avoid crushing the slide and damaging the objective lens.
1) Find the observation target under low magnification, gradually zoom in under medium and high magnification, place the part to be observed in the center of the field of vision, adjust the light source and iridescent aperture to maximize the light passing through the condenser.
2) Turn the coarse quasi-focus screw, rotate the lens barrel up (or lower the stage) about 2 cm, and add a small drop of cedar oil to the microscope inspection part of the slide.
3) Slowly turn the coarse quasi-focus screw back, and observe from the side at the same time, until the oil lens is immersed in the oil drop, and the lens is almost in contact with the specimen. 4. Observe from the eyepiece and fine-tune with the fine-focus screw until the object image is clear. 5. After the microscope inspection, rotate the lens away from the glass slide and clean the lens immediately. Generally, first wipe off the cedar oil drops on the lens with a lens cleaning paper. Then dip a little ether-alcohol mixture (2:3) with lens tissue to wipe off the residual oil, and finally wipe it off with a clean lens tissue (pay attention to wipe in one direction).
