How to measure solid colors with a Spectrophotometer ?

We all know that there are ten million colors that can be distinguished. The quality standard "color" is becoming more and more important in various industries. Uniform colors affect customer preferences. This is especially important when the individual components of the final product are manufactured at different company sites, or is more complicated when multiple suppliers are involved. However, the final color needs to be correct.

Visual color perception is affected by varying color sensitivities from person to person (mood, age, etc.), and from environmental differences such as brightness and color. This is a digital world, more and more people will be more willing to believe in data rather than judge from manufacturing, so color measuring machines are very important to quality inspection departments.

Color perception depends on the interaction of three elements: light source, object and observer.

1. The color changes with the light source

So lighting needs to be agreed upon and used when we compare color differences. The visible spectrum is from 400 to 700nm.

In general, important lighting is daylight D65, C, A, f2 and f11.

2. There is no color without an observer

Reflected light from colored objects enters the eye through the lens and hits the retina. Today, however, the observer is a spectrometer, which stimulates the brain to create an impression of color. In order to determine the sensitivity to the receptors, CIE1931 and 1964 carried out systematic visual tests, according to the test results, observers of grade 2 and grade 10 were standardized to represent a small and large visual field respectively.

3. Object

The optical properties of the object are variables that alone need to be measured.

A color system combining data from three elements: light source, viewer and object, which was suggested by the CIE and widely used today, is the CIELAB system.

spectrometer model

There are two types of instruments for measuring color 45/0 (it uses a 45 degree ambient light and a 0 degree view normal to the sample plane)

Sphere geometry (which diffusely illuminates the sample by integrating a sphere with a white coating)

Conclusion

Only measurements made under certain conditions can be compared. Therefore, it is necessary to note the following information in the color measurement report: color instrument (geometry), illumination/observer, color system, sample preparation.