The Science of Spectrophotometry: How Spectrophotometer Measure Color

The spectrophotometer has high accuracy and uses a pre positioning board setting, eliminating the need for standard blackboards and whiteboards in the calibration process of traditional colorimeters and colorimeters. The built-in software has powerful functions, including all necessary color equations, standard light sources suitable for different tasks, and a large number of specific industry and application indicators

This type of product is currently the mainstream technology in the field of color testers because it can accurately measure the specific values of colors. It is a high-end product and the price will also be higher.

Concept of spectrophotometer:
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.

Measuring principle:
The spectrophotometer can measure the “reflectance curve” of each color point (10nm or 20nm wavelength interval), and can simulate multiple light sources.

Design principle：
The spectrophotometer is designed based on the principle of spectrophotometer, while the ordinary colorimeter is designed based on the principle of tristimulus value. The color separation and measurement instrument has high accuracy and increasing versatility.

Due to this reason, it reduces the influence of the sample surface, making it particularly suitable for color quality monitoring and computer color matching, as well as SCE (a measurement method that excludes specular reflection. The results obtained from this type of measurement are similar to those observed with the naked eye). Due to its ability to measure reflectivity at each wavelength, it is suitable for complex color analysis.

The science of spectrophotometry:
A spectrophotometer is a spectrophotometric method that compares the reflected (transmitted) light energy of a sample with the standard reflected (transmitted) light energy under the same conditions to obtain the spectral reflectance of the sample at each wavelength;

Then, using the standard observer and standard light source provided by CIE, calculate the tristimulus values X, Y, and Z according to the following formula. Then, calculate the chromaticity coordinates x.y, CIELAB chromaticity parameters, etc. from X, Y, and Z according to CIEYxy, CIELAB, and other formulas.

The spectrophotometer determines the color parameters of the sample by detecting its spectral composition. It can not only provide the absolute values and color difference values △ E of X, Y, and Z, but also provide the spectral reflectance value of the object and draw the spectral reflectance curve of the object color.

Therefore, it is widely used in color matching and color analysis. This type of instrument can achieve high-precision color measurement, calibrate photoelectric integrated color measuring instruments, establish color standards, etc. The earliest developed instrument in China is the DSCD-920 spectrophotometer from LISUN. Therefore, a spectrophotometer is the preferred instrument for color measurement.

Benchtop Spectrophotometer (Reflectance and Transmittance) DSCD-920 adopts 7 inches touch screen, full wavelength range, Android operate system. Illumination : reflectance D/8° and transmittance D/0°(UV included / UV excluded), high accuracy for color measurement, large storage memory, PC software, because of above advantages, it is used in laboratory for color analysis and communication

DSCD-920_Desktop Spectroradiometer

Lisun Instruments Limited was found by LISUN GROUP in 2003. LISUN quality system has been strictly certified by ISO9001:2015. As a CIE Membership, LISUN products are designed based on CIE, IEC and other international or national standards. All products passed CE certificate and authenticated by the third party lab.

Our main products are Goniophotometer, Integrating Sphere, Spectroradiometer, Surge Generator, ESD Simulator Guns, EMI Receiver, EMC Test Equipment, Electrical Safety Tester, Environmental Chamber, Temperature Chamber, Climate Chamber, Thermal Chamber, Salt Spray Test, Dust Test Chamber, Waterproof Test, RoHS Test (EDXRF), Glow Wire Test and Needle Flame Test.

Please feel free to contact us if you need any support.
Tech Dep: Service@Lisungroup.com, Cell/WhatsApp:+8615317907381
Sales Dep: Sales@Lisungroup.com, Cell/WhatsApp:+8618117273997