1. Detection angle: In addition, the detection angle will directly affect the evaluation results. According to international standards, only two detection angles can be used, namely:
45 tilt table: 45 light source, zero degree detection (45-0)
In this layout, a special 45-degree fixed-angle worktable must be used, so that the light source can irradiate the sample from 45 degrees and detect the sample from zero (vertical).
Zero degree light source, 45 degree detection (0-45 degrees)
That is, the light source shines on the sample from zero (vertical) incident angle, and the detector detects the sample light source from 45 degrees.
2. Light box maintenance
A perfect maintenance plan can ensure that your light box is in a standard state for a long time: be careful not to pollute the inner wall of the light box when using it; If stains or paint peeling are found, someone should be sent to correct or replace the inner wall plate immediately, and the service time or brightness of the lamp tube should be checked frequently.
3. Check the placement position of the sample
No matter which of the above detection methods is used, it must be noted that the test samples should be placed in the middle of the light box as much as possible to reduce the influence of external light sources. In addition, the most important thing is that when it is necessary to compare the colors of two or more objects, try not to watch them overlapping. It is best to put them side by side in a light box for comparison.
4. It has the function of testing metamerism effect.
The so-called metamerism effect means that under a certain light source, the color displayed by the sample is the same as the requirements, while under another light source, the color difference is unacceptable.
We can see the same sample from the picture. Under D65 light source, the color is no different from the standard, but under A light source, the color of the sample is unacceptable. Therefore, all equipment equipped with color matching light sources must be equipped with two or more light sources in order to test the same color difference effect.
5. Implement the requirements for environmental factors in the process of color matching.
All external light that has the opportunity to irradiate the test sample must be avoided as much as possible. If the window is in the field of vision, it should also be covered with gray curtains, so it is most ideal to use color matching light boxes in the darkroom. Another thing that is often overlooked is that you must not put other sundries in the color light box.
6. Requirements for replacing light source (instantaneous lighting-quick start)
According to the experience of daily life, in our eyes, it is like having a register. When the color changes in a very short time, we can clearly feel it. Therefore, when detecting metamerism, if you want to change the light source, you must do it in an instant. Don't flash like the lighting tube we use every day, because it will irritate our eyes and affect the evaluation results.
7. Record the use time of standard lamps.
All standard color matching light sources are also produced with tubes or bulbs, and manufacturers will also list that the quality of their products will remain within acceptable tolerances within a certain operating period. Therefore, an accurate time recorder is essential. Usually this kind of lamp needs to be replaced after it has been used for more than 2000 hours or a year.
8. Arrangement position of lamp tubes
Although there is no specific requirement for the arrangement position of lamps and lanterns, their distribution position must be that there are uniform light sources in the color matching light box, and they cannot be biased to a certain area.
9. Ultraviolet light source
Because fluorescent and whitening dyes are widely used in industry, the best way to detect these effects is to use ultraviolet lamp, because ultraviolet light will produce obvious brightness changes on substances stained with fluorescent agents, which are easy to be detected by naked eyes.