What does the optical microscope's oil lens' underlying concept entail? Use the oil lens to detect microbes
Oil lens, one of optical microscopes, when used, the lens is immersed in oil (usually cedar oil), used to observe finer structures, it is one of the microscopes commonly used in laboratories, the definition is slightly higher than ordinary optical microscopes, used to observe chlamydia, bacteria, organelles, etc. The lens of the oil lens is very small, and the light passes through the gap between the glass slide and the oil lens...
On the microscope, the magnification of 100 times is the oil lens. When it is in use, cedar oil needs to be dripped on the glass slide to see the objects under the microscope clearly.
When using an oil lens, it is necessary to add cedar oil to the glass slide. This is because the magnification of the oil lens is high, and the lens is small. When the light passes through medium objects of different densities (slide→air→lens), part of the light will be refracted and lost. If cedar oil (n=1.515), which is similar to the refractive index of glass (n=1.52), is added between the lens and the glass, the light entering the oil lens will increase, the brightness of the field of view will be enhanced, and the object image will be clear.
Microorganisms are generally small, and when observed with an oil immersion lens, the magnification is large and the observation is relatively clear!
To put it simply, the refractive index of cedar oil is smaller than that of air, and light passing through small cells will enter the objective lens more and be easier to observe
Recognition of microscope low power, high power and oil lens:
(1) Indicate the magnification 10×, 40×, 100×, or 10/0.25, 40/0.65, 100/1.25.
(2) The low magnification lens is the shortest, the high magnification lens is longer, and the oil lens is the longest.
(3) The mirror hole in front of the lens is the largest for the low-magnification lens, larger for the high-power lens, and the smallest for the oil lens.
(4) The oil lens is often engraved with a black ring, or the word "oil".
