The spectrophotometer uses the grating spectrophotometer principle for color measurement. A grating is an optical element that is engraved with a set of parallel periodic lines or grooves (often inclined) on a plane.
When a beam of compound light is incident on the grating plane, its periodic structure will undergo diffraction, and the transmitted or reflected diffraction light will also interfere. The energy of the light will be redistributed, and different wavelengths of light will travel in different directions, forming a specific wavelength superposition extremum at a certain position, thereby achieving light splitting.
Spectroscopic colorimeters can produce spectral curves, which are equivalent to a color’s ID card and are unique. Therefore, the color data read by the spectrophotometer is absolutely accurate.
The role of spectrophotometer in colorimetry:
The chemical industries such as textiles, printing and dyeing, petroleum, and batteries often generate a lot of industrial wastewater during the production process. The national standards for detecting the chromaticity of wastewater mainly use platinum cobalt colorimetry and dilution multiple method.
The platinum cobalt chromaticity is expressed in Hazen units, with 1 milligram of platinum per liter of solution containing chloroplatinic acid and 2 milligrams of hexahydrate cobalt chloride solution having a platinum cobalt chromaticity of 1 unit. The general range of values is between 1 and 500. Suitable for measuring the color of liquid chemical products that are transparent or slightly close to the reference platinum cobalt color number, this color characteristic is usually brownish yellow.
Limitations of human eye colorimetry; The platinum cobalt colorimetric method is based on human eye judgment, and the color is influenced by environmental light sources, observation angles, and other factors. In actual visual colorimetry, there are certain differences.
Platinum cobalt chromaticity can not only be applied in water quality analysis, but also be used to measure the chromaticity of solutions of chemicals, petrochemical products, such as glycerol, solvents, plasticizers, carbon tetrachloride, petroleum alcohols, etc.
Given the shortcomings of the platinum cobalt colorimetric method in actual color comparison, a spectrophotometer can also be used to compare solution colors.
The use of a spectrophotometer for measurement has the following three major advantages:
1. There is no need to configure a solution and no need to consider material storage issues;
2. The instrument is easy to operate and can be directly measured;
3. Platinum cobalt data is clear at a glance.
The desktop spectrophotometer can measure the chromaticity indicators of platinum cobalt, Gardner, Saybolt, and ASTM.
The role of spectrophotometer in color management:
The spectrophotometer can display chromaticity information based on the internally set chromaticity space and calculation formula, and output it in digital form. In addition, spectrophotometer can also analyze potential spectral data information based on chromaticity data.
The spectrophotometer is designed for data comparison and simulation of visual chromaticity, and is also an important auxiliary tool for computer color matching, which can help major manufacturers complete the analysis, processing, and monitoring of spectral and chromaticity information perfectly.
In the use of spectrophotometer, a crucial data equation – the color tolerance equation – is involved. In fact, we usually refer to the tolerance range, and in industrial batch production, there are tolerances to control the product and qualification status, which is fast and reasonable.
The spectrophotometer wants to measure the color difference of the product and control it, which is the same as a regular color difference meter. Firstly, it needs to measure the information of the standard sample product, and then compare the color information of the measured sample to obtain color difference data.
Calculate whiteness. It can perform white measurement on the whitened sample according to relevant formulas, and then provide specific whiteness values to see if they can meet the standard requirements.
Calculate the strength of the dye. Different dye batches may result in dyeing differences. Therefore, a spectrophotometer can be used to read the relevant finished product samples, and then see the differences between the products produced by these two different batches of dyes. Then, the relevant differences can be filled in the correction coefficient, and the formula can be automatically adjusted to ensure consistent dyeing results.
Calculate the color depth. Because in the actual production process, there may be certain differences in color depth due to differences in formula or production process, and some of these differences cannot be judged by the naked eye. In this case, it is necessary to analyze them through professional equipment such as a spectrophotometer.
Application of spectrophotometer:
1. Food industry
The color of food has a significant impact on people’s appetite, so the food industry has very high requirements for color. The spectrophotometer can quickly measure the color of food to ensure good color and compliance with safety standards.
2. Cosmetics industry
The color of cosmetics is very important for consumers, and good colors can help consumers quickly distinguish different brands. A spectrophotometer can help cosmetic manufacturers ensure that their products have colors that match standard colors.
3. Textile industry
The color of textiles is also very important as it can affect consumers’ purchasing decisions. A spectrophotometer can help textile manufacturers ensure that their products have accurate color and chromaticity values.
4. Semiconductor industry
In the semiconductor manufacturing process, spectrophotometer can help detect the color of transistors, LEDs, and other electronic components. This is crucial for maintaining product consistency and quality.
Advantages of spectrophotometer:
1. High measurement accuracy
The spectrophotometer has high measurement accuracy and can achieve extremely high color accuracy. This is very important for applications that require high-precision color measurement, such as color identification, color matching, etc.
2. Overall measurement speed is fast
In traditional color measurement methods, multiple measurements are required to obtain high-precision results. The spectrophotometer can quickly complete the overall measurement, saving a lot of time.
3. With a recorder
The spectrophotometer has a recorder that can save measurement data during measurement. This is very convenient for later data analysis and comparison.
4. Easy to use
The spectrophotometer is convenient to use and easy to operate. There is no complex operation process, and color measurement can be completed in a few simple steps.
Benchtop Spectrophotometer (Transmittance) DSCD-910 is good performance and specially designed for testing the transparent material’s transmittance, absorbance, chromaticity value and other parameters.
DSCD-910_Benchtop Spectrophotometer (Transmittance)
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