Which are the main applications of optical microscopes?
Optical microscope is an ancient and young scientific tool. It has a history of three hundred years since its birth. Optical microscope is widely used, such as in biology, chemistry, physics, astronomy, etc. in some scientific research work. All are inseparable from the microscope.
At present, it has almost become the image endorsement of science and technology. You only need to look at its frequent appearance in media reports on science and technology to see that this statement is true.
In biology, laboratories are inseparable from this kind of experimental equipment, which can help learners study the unknown world and understand the world.
Hospitals are the largest application places for microscopes, which are mainly used to examine changes in patients' body fluids, germs that invade the human body, changes in cell tissue structure, and other information, providing doctors with reference and verification methods for formulating treatment plans. In microsurgery, the microscope is the most important tool for doctors; in agriculture, breeding, pest control and other tasks are inseparable from the help of the microscope; in industrial production, the processing inspection and assembly adjustment of fine parts, and the study of material properties are all possible with the microscope. Where to show your skills; criminal investigators often rely on microscopes to analyze various microscopic traces of crimes as an important means to determine the real culprits; environmental protection departments also rely on microscopes when detecting various solid pollutants; geological and mining engineers and cultural relics and archaeologists use microscopes The clues discovered by the microscope can determine the mineral deposits buried deep in the ground or infer the dust-covered historical truth; even people's daily life is inseparable from microscopes, such as the beauty and hairdressing industry, which can use microscopes to detect skin, hair quality, etc. Get the best results. It can be seen how closely the microscope is integrated with people's production and life.
Microscopes can be roughly classified according to different application purposes. The four common categories are biological microscopes, metallographic microscopes, stereo microscopes, and polarizing microscopes. As the name suggests, biological microscopes are mainly used in biomedicine, and the objects of observation are mostly transparent or translucent microscopic objects; metallographic microscopes are mainly used to observe the surfaces of opaque objects, such as the metallographic structure and surface defects of materials; stereomicroscopes are used to observe microscopic objects. While the object is magnified and imaged, the orientation of the object and the image relative to the human eye is consistent, and there is a sense of depth, which is in line with people's regular visual habits; polarizing microscopes use the transmission or reflection characteristics of polarized light of different materials to distinguish different micro-objects Component. In addition, some special types can also be subdivided, such as an inverted biological microscope or a culture microscope, which is a biological microscope mainly used to observe culture through the bottom of a culture vessel; a fluorescence microscope uses certain substances to absorb specific shorter wavelength light. The characteristics of emitting specific longer wavelength light to discover the existence of these substances and determine their content; a comparison microscope can form juxtaposed or overlapping images of two objects in the same field of view to compare the similarities and differences between the 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 condensers, all of which are complicated magnifying lenses made of various optical glasses. The objective lens magnifies the specimen into an image, and its magnification M object is determined by the following formula: M object =Δ∕f' object , where f' object is the focal length of the objective lens, and Δ can be understood as the distance between the objective lens and the eyepiece. The eyepiece magnifies the image formed by the objective lens again into a virtual image for observation at 250mm in front of the person's eyes. This is the most comfortable observation position for most people. The magnification of the eyepiece is M eye=250/f' eye, f' eye is the eyepiece. the focal length. The total magnification of the microscope is the product of the objective lens and the eyepiece, that is, M=M object*M eyepiece=Δ*250∕f' eyepiece*f; object. It can be seen that reducing the focal length of the objective lens and eyepiece will increase the total magnification. This is the key to using a microscope to see bacteria and other microorganisms, and it is also the difference from ordinary magnifying glasses.
