How to establish color standards, improve product appearance, control color quality, and then perform computer color matching? You need to know how to use color measurement instruments.
At present, there are various types and brands of color measurement instruments in the market. Not everyone has a deep understanding of colorimeters, and different instruments may have great differences in price or measure different results. Why are some called colorimeters and some called spectrophotometers? What is the difference between these instruments? What industries are they used in? This is a difficult problem when we have to make a choice.
Here we have a detailed introduction.
What is the “colorimeter” and “spectrophotometer”?
Colorimeter
Colorimeter” can be used to measure the color difference between two samples. Accuracy is not very high, usually can not accurately measure the absolute value of the color coordinate space (L, a, b value). It is used in the scenario of measuring the color difference (ΔE) between two samples (usually between the standard and the sample). It has no data on the absolute value of the color, so there is no way to exchange data or to create and manage its own database of color standards.
Spectrophotometer
Spectrophotometer is more accurate and uses a pre-positioning plate setting. Eliminates the need for traditional colorimeter, colorimeter calibration process using a standard blackboard and whiteboard. Built-in software is powerful and contains all necessary color equations. Standard light sources are suitable for different tasks, as well as a large number of industry and application-specific indicators. You can click here to learn more details of a spectrophotometer from the fru brand.
Differences in characteristics
Spectrophotometer is designed according to the principle of spectrophotometer type, and the common colorimeter is designed according to the principle of tri-stimulus value type. Spectrophotometer has high accuracy and increasing versatility. The color spectrophotometer can measure SCI simultaneously (it is a method that includes specular reflection for measurement. For this reason, it minimizes the influence of the sample surface and is particularly suitable for color quality monitoring and computer color matching) and SCE (a measurement method that excludes specular reflections. (The results obtained from this type of measurement are more similar to those observed by the naked eye). Since it can measure reflectance at each wavelength, it is suitable for complex color analysis and is of course relatively expensive. Three stimulus value colorimeter has a relatively low price, compact shape, outstanding convenience and easy to operate.
Measurement principle
Colorimeter can automatically compare the color difference between the sample and the inspected products, output CIE L, a, b three groups of data and colorimetric △ E, △ L, △ a, △ b four groups of color difference data. Different from the simple colorimeter color measurement method, the spectrophotometer can measure the “reflectance curve” of each color point (10nm or 20nm wavelength interval), while the colorimeter can not. Spectrophotometer can simulate a variety of light sources, while the colorimeter generally only has up to two simulated light sources.
Light source
In the color measurement instrument, what light source to choose, should first consider the stability, light source directionality, life and the effectiveness of the final obtained spectral curve. Currently used mostly LED lamps and xenon lamps are two light sources.
Xenon lamps are generally used mainly for ultraviolet light source measurement, which can emit a short period of high-intensity arc light, but it is difficult to produce repeated arc light of equal intensity. In addition, the xenon light source requires a more complex high-voltage oscillation excitation circuit, maintenance is also very complex, in addition to replacing the bulb, but also to replace the entire set of capacitors, so the price is more expensive.
In the current standard color measurement instruments, the use of LED lights from the technical and economic are appropriate. Especially portable instruments need to be lightweight, power-saving, easy to maintain and operate. Color spectrum color measurement instruments use long-life CLEDs (full-band balanced Led light source), so you don’t have to worry about the frequent need to replace the light source.
