With the research and development of the methodology and instruments of laboratory medicine, the means of medical laboratory has developed from a single optical microscope to an automatic and semi-automatic analytical instrument. Biochemical inspection sub instrument is the main component of medical inspection instruments, which is the combination of physics, chemistry, optics and biomedicine. It mainly includes spectrophotometer, automatic biochemical analyzer, ultraviolet, visible light photometer, fluorescence photometer, etc. Its structure mainly consists of optical system (light path) and circuit system (circuit). In order to keep the instrument in good working condition, the instrument shall be maintained regularly.
1. Grating
Grating is the main dispersion component of continuous spectrum analyzer. Because of its uniform dispersion, clear spectral lines, wide operating band and other characteristics, it has basically replaced the prism and become the leading role of dispersion elements. Grating is an optical element composed of many parallel slits with equal width and spacing, which works according to the principle of light diffraction and dry radiation. Its surface is coated with a layer of aluminum film, which is soft and easy to scratch. Therefore, in the process of maintenance and repair, handle with care and do not wipe with hands or other objects. Otherwise, it will cause permanent damage to the aluminum film. If there is dirt and other impurities on the aluminum film, it can be blown away with a blowing balloon.
2. Collimator
The collimating mirror is actually a concave mirror. It works according to the property of the concave mirror, that is, the paraxial ray parallel to the main axis will be focused on its focal plane after being reflected by the concave mirror. Most collimating mirrors are spherical mirrors, and some are rotating paraboloidal mirrors. The surface of collimating mirror is also usually coated with aluminum film. In the visible light area, in order to protect the aluminum film from damage, a layer of silicon dioxide protective layer is often coated outside the aluminum film. However, in the ultraviolet area, in order to ensure high reflectivity, there is generally no such protective layer. For collimating mirror without protective layer, its maintenance method is the same as that of grating. It is forbidden to wipe with hands or other hard objects during maintenance and repair.
3. Colorimeter
The cuvette is also called colorimetric cell, cuvette and cuvette. It is an accessory of biochemical analysis instrument. The cuvette is mainly used to hold the sample solution for colorimetric analysis in the optical system. In order to obtain accurate measurement results, the correct use, maintenance and care of the cuvette are particularly important. In the visible light range, the cuvette is usually made of colorless optical glass or plastic; It is usually made of quartz glass in the ultraviolet light area. In addition to light transmission, the cuvette should also have strong corrosion resistance. The cuvette is generally matched with the instrument and cannot be mixed, otherwise it will bring large measurement error. The method to check whether the cuvettes meet the requirements is to put the same colored solution in each cuvette, measure it at the specified wavelength, and the transmission error read out should be less than 5}. Otherwise, the error is too large and should not be used. When using the cuvette, pay attention to its placement direction, because its light transmission capacity may change if the light transmission direction is changed backward. Some cuvettes have a front to indicate the direction of light. When holding liquid, the liquid volume should be slightly more than I/2 of the cuvette, and the cuvette surface should not be stuck with liquid or other impurities. Otherwise, the measurement results will be seriously affected due to the reflection and refraction of light. After the measurement, it shall be immediately put into distilled water for flushing, and the inner wall shall be regularly checked for residues to keep it clean.
