A colorimeter is an instrument for quantitative analysis by comparing the color of the tested solution with the standard solution. It is an instrument for measuring the color characteristics of materials. The main purpose of the colorimeter is to measure and analyze the color, hue, and color value of the tested material. Colorimeters can be divided into two types:
- Visual Colorimeter
- Photoelectric Colorimeter
The Lovibond colorimeter is a new generation of visual color measuring instruments. It uses the Lovibond color scale to measure various liquids, colloids, and colorimetric solid and powder samples.
Difference between a Visual Colorimeter and a Photoelectric Colorimeter?
Visual colorimeter uses different amounts of the standard solution of the object to be tested in the same set of colorimetric tubes, first develop the color according to the analysis steps and prepare a standard color scale with gradually changing color. The color of the sample solution is also developed under the same conditions, and compared with the standard color scale, visually find the standard with a similar color and luster, and calculate and determine the components to be tested in the sample based on the amount of the standard solution contained in it.
Photoelectric colorimeters eliminate subjective errors, improve measurement accuracy, and can improve selectivity by eliminating interference by selecting filters. However, the photoelectric colorimeter uses a tungsten light source and filter, which is only suitable for the visible spectral region and can only obtain compound light in a certain wavelength range rather than a monochromatic beam.
Lovibond Colorimeter Application
Rubber can be made into sealing products and can also be made into decorations of various colors, toys, cars, sports equipment, etc. It can be seen in almost every corner. Selecting the appropriate coating method and colorant can also significantly improve the weather resistance, heat resistance, corrosion resistance, electrical properties, optical properties, and identification of rubber products during tooling. Therefore, colors and colorants are indispensable work in the rubber industry.
Since there is a coloring link, the chromaticity test is indispensable to test the quality of rubber products. Lovibond colorimeter is a professional instrument for measuring chromaticity. It is widely used in rubber, grain, plastic, and other industries.
Steps To Calibrate Lovibond Colorimeter Accuracy?
Step #1: According to the customer’s use of the instrument to be tested, select 2 to 3 reference oils of different colors and put them into the liquid sample pools equipped with the instrument and meeting the requirements of the regulations (the specifications of the liquid sample pools are based on the relevant oil testing standards. Select), and put them into the sample chamber of the instrument under test respectively;
Step #2: Use the instrument to be inspected (that is, use the color filter equipped with the instrument) for the above reference oil, according to the requirements of the relevant oil testing standards; first fix the yellow color filter, then adjust the corresponding color filter, and conduct visual observation until When the two fields of view achieve the same color matching, the value obtained at this time is the measured value of the reference oil;
Step #3: Remove the color filter in the tested instrument, replace it with a standard Lovibond color filter, and measure according to the method in the second step. The value obtained is the nominal value of the reference oil.
Step #4: The difference between the measured value of the reference oil and the nominal value is the measurement tolerance of the instrument, and the value is compared and determined with the relevant indicators specified in the regulations.
How to Choose Lovibond?
Lovibond visual colorimeter requires manual reading. This makes it prone to operator reading errors, while Lovibond electronic spectropolarimeter can provide more objective and real data.
1) Determine the instrument type according to the sample’s properties
- Clear liquid, both Lovibond visual and electronic types can be used.
- For translucent and turbid liquids and solids, you should select the Lovibond visual type. The electronic type is not applicable in this case,
- Fats or waxes can be turned into clear liquids under heating conditions, and electronic products with heating units can be selected
2) According to the user’s quality standard (standard method), the corresponding sample condition or measurement range, such as organic solvent toluene, acetone, and other impurities judgment, the chromaticity rating generally adopts the platinum cobalt chromaticity standard, and petroleum products include aviation kerosene, Gasoline and diesel generally use the ASTMD1500 standard, and honey products use the standard of common characteristics and so on.
3) Determine the applicable instrument model according to the chromaticity standard. In general, some common standards can be met by many instruments, and some instruments have multiple built-in standards.
4) Determine the model based on the budget. Customers with limited budgets or customers who only need to measure a single product can choose Lovibond single-parameter electronic colorimeter or visual colorimeter. Commodity inspection, animal and plant inspection departments, and scientific research departments can choose Lovibond multi-parameter, full-parameter electronic colorimeter.
5) Determine the Configuration of Optional Accessories
- Visual colorimeters generally do not require weaving upgrades.
- For Model F, if you need to measure solids, an optional solid sample accessory kit is available
- For the electronic colorimeter, in addition to the standard colorimetric standard, if you need to select other chromaticity standards, please select the upgraded color standard and the cuvettes and colorimetric tubes with the same optical path of the corresponding chromaticity standard (special specifications. The colorimetric tube needs to be equipped with an adapter)
- For the electronic colorimeter, determine whether it is necessary to select the built-in heating unit and the corresponding borosilicate glass cuvettes according to the situation of the sample (ordinary optical glass can withstand temperatures up to 60°C)
- For the electronic colorimeter, determine whether to select Windows software according to the needs of data processing.
6) Configure Consumables, Spare Parts, Replacement Chromaticity Standards, Standard Filters, And Standard Solutions As Required.
- Standard filters and standard solutions are used for the daily verification of the instrument. According to the measured chromaticity standard and chromaticity range, select a fixed standard or customized] to determine the normal working state of the instrument and the reliability of the data. Standard filters are easy to use, while standard solutions maximize the simulation of the measurement process.
- Lights, sample tanks, and reflectors may need to be replaced periodically due to aging or contamination.
- The colorimetric standard of the visual colorimeter needs to be replaced due to aging or contamination. A full set of chromaticity standards or a single chromaticity standard can be replaced as required.
- Difference Between A Photoelectric Colorimeter And A Spectrophotometer
- The Concept Is Different:
- A colorimeter is a chemical analysis instrument. An instrument that compares the intensity of color by passing light through a standard solution (or glass slide) and a sample solution, respectively. For colorimetric analysis. Generally divided into visual colorimeter and photoelectric colorimeter, and photometer belongs to the latter.
- The Wavelength Selection Range Is Different:
- Photoelectric colorimeters, urine analysis, and microplate readers use filters as spectroscopic components, and the wavelength selection range is limited.
- Spectrophotometers and automatic biochemical analyzers use prisms or gratings as light-splitting elements, which can obtain continuously.
- Monochromators Are Different:
- The colorimeter uses a filter to filter out other stray light, and the purity of the light is low, and the accuracy is poor.
- The spectrophotometer adopts a spectroscopic system (grating or diamond mirror) to obtain monochromatic light, with high purity and high precision light.
- The Principle Of Colorimeter
- When monochromatic light passes through a solution with the same thickness and a small concentration, according to the Lambert-Beer law, the degree to which the light is absorbed by the solution, called absorbance, is proportional to the concentration of the solution and proportional to the thickness of the solution. The intensity of the light is weakened due to the absorption of part of the light energy by the solution. If the concentration (or thickness) of the solution is constant, the greater the thickness (concentration) of the solution, the more obvious the weakening of the light intensity.
- Widely used in plastics and printing industries, mainly according to the Lab and Lch principles of CIE color space, the measurement shows the color difference △E and △Lab between the sample and the tested sample
- Correlation analysis method
- △E The size of the total color difference
- △L+ means white, △L- means black
- △a+ means reddish, △a- means greenish
- △b+ means yellowish, △b- means bluish
Lovibond colorimeters are often incorrectly just called colorimeters. However, the Lovibond colorimeters are different from other colorimeters in terms of functionality. The two have different working principles. Lovibond colorimeters are used to perform colorimetric assays to determine, from the color, the quantity of a known substance resolved in a specific reaction reagent yield.