How to use the parafocal helix in the tool microscope
Using the quasi-focus screw to adjust the focal length and finding the object image can be said to be the most important step in the use of a tool microscope. Do not make the following mistakes during operation: one is to directly adjust the focus under a high-magnification lens; When it reaches 2~3cm, it is still adjusted upwards, and the speed of turning the focus screw is very fast. The first two types of errors often cause the objective lens to interfere with the mounting film and damage the mounting film or lens, while the third error is the most common phenomenon when using a microscope.
To adjust the focal length, it must be lowered at a low magnification. Turn the coarse quasi-focus screw first, so that the lens barrel slowly descends, and the objective lens is close to the slide glass, but do not let the objective lens touch the slide glass. During this process, the eyes should look at the objective lens from the side. , then look into the eyepiece with your left eye, and slowly adjust the coarse quasi-focus screw in reverse, so that the lens barrel rises slowly until you see the object image. At the same time, the object distance of a general microscope is about 1 cm, so if the object distance If the distance is more than 1 cm, but the object image is still not seen, it may be that the specimen is not in the field of view or the speed of turning the coarse and accurate focus screw is too fast. At this time, the position of the film should be adjusted, and then repeat the above steps. When the object image is blurred, it is necessary to use the fine focus screw adjustment. Only in this way can the search range be narrowed and the speed of finding the object image can be increased.
How to Adjust a Stereo Microscope
1. Adjust the hinges of the binocular tubes so that the distance between the eyepieces matches the interpupillary distance of the eyes.
2. Adjust the zero point on the eyepiece scale line to correspond to the white point on the eyepiece (if using an eyepiece micrometer, adjust the eyepiece with the eyepiece micrometer until the eye can clearly see the image of the eyepiece micrometer) .
3. Place the sample on the stage and illuminate it.
4. Adjust the magnification changer to the maximum magnification and focus on the sample details.
5. Adjust the magnification changer to the minimum magnification, and adjust the diopter compensators on the two eyepieces. If an eyepiece micrometer is already placed in one of the eyepieces, only the other eyepiece needs to be adjusted.
After adjustment, the details of the sample remain in focus throughout the entire zoom range without the need for adjustment.
