What are the main applications of optical microscopes in
Optical microscope is an ancient and young scientific tool that has a history of 300 years since its birth. Its applications are very extensive, such as in biology, chemistry, physics, astronomy, and other scientific research work.
At present, it has almost become an image spokesperson for science and technology. You only need to see its frequent appearance in media reports about science and technology to see that this statement is also true.
In biology, laboratories cannot do without such experimental instruments, which can help learners study the unknown world; Get to know the world.
Hospitals are a major application of microscopes, mainly used to examine patients' fluid changes, invading bacteria, changes in cellular tissue structure, and other information, providing doctors with reference and verification methods for formulating treatment plans. In genetic engineering and microsurgery, microscopes are also tools for doctors; In agriculture, breeding, pest control, and other work cannot do without the help of microscopes; In industrial production, the processing, inspection, assembly adjustment, and material performance research of fine parts are areas where microscopes can demonstrate their expertise; Criminal investigators often rely on microscopes to analyze various microscopic crimes as an important means of determining the true culprit; The environmental protection department also needs to use a microscope when detecting various solid pollutants; Geological and mining engineers and archaeological workers can use the clues discovered by microscopes to determine deep underground mineral deposits or infer the historical truth of dust cover; Even people's daily lives cannot be separated from microscopes, such as in the beauty and hair industry. Microscopes can be used to detect skin, hair quality, etc., and achieve excellent results. It can be seen how closely the microscope is integrated with people's production and life.
According to different application purposes, microscopes can be roughly classified into four categories: biological microscopes, metallographic microscopes, stereomicroscopes, and polarizing microscopes. As the name suggests, biological microscopes are mainly used in biomedical fields, with observation objects mostly being transparent or semi transparent microbodies; Metallographic microscopy is mainly used to observe the surface of opaque objects, such as the metallographic structure and surface defects of materials; Stereoscopic microscopy not only magnifies and images micro objects, but also aligns the orientation of objects and images relative to the human eye, and has a longitudinal depth, which is in line with human conventional visual habits; A polarizing microscope uses the transmission or reflection characteristics of polarized light by different materials to distinguish different microscopic components. In addition, some special types can also be subdivided, such as inverted biological microscopes or culture microscopes, which are mainly used to observe culture through the bottom of culture vessels; Fluorescence microscopy utilizes the characteristic of certain substances absorbing specific shorter wavelength light and emitting specific longer wavelength light to discover the presence of these substances and determine their content; A comparative microscope can form parallel or overlapping images of two objects in the same field of view, in order to compare the similarities and differences between two objects.
Traditional optical microscopes are mainly composed of optical systems and the mechanical structures that support them. The optical systems include objective lenses, eyepieces, and condenser lenses, all of which are complex magnifying glasses made of various optical glasses. The objective lens magnifies the specimen for imaging, and its magnification, M object, is determined by the following equation: M object= Δ∕ F 'object, where f' object is the focal length of the objective lens, Δ It can be understood as the distance between the objective lens and the eyepiece. The eyepiece magnifies the image formed by the objective lens again, forming a virtual image for observation at a distance of 250mm in front of the human eye. This is a comfortable observation position for most people. The magnification of the eyepiece is M mesh=250/f 'mesh, where f' mesh is the focal length of the eyepiece. The total magnification of a microscope is the product of the objective and eyepiece, i.e. M=M object * M mesh= Δ* 250/f 'mesh * f; Things. It can be seen that reducing the focal length of the objective and eyepiece will increase the overall magnification, which is the key to using a microscope to see bacteria and other microorganisms, and also the difference between it and a regular magnifying glass.
