There are so many color difference meters on the market, and the parameters are complex. Not to mention that so many parameters can't be understood. Even if I understand them, I don't know whether this parameter is suitable for me. Today, we will measure the light source, one of the parameters of the color difference instrument, to introduce the differences and functions of each light source.
I believe we all have such experience. When we buy a dress in the mall and leave the store, the color of the dress is different. This is because the spectral power distribution of the lighting source in the mall is different from that of the sunlight, which leads to the different color of the clothes we see. Therefore, in the actual production process, it is necessary to unify the lighting source to detect the color.

Comparison diagram under different lighting sources

Among the standard light sources recommended by the International Commission on illumination (CIE), they can be mainly divided into different types such as a / B / C / D / E / F. the difference between the above standard light sources is the difference of relative spectral power distribution. The following describes the differences between the lighting light source and the test light source in the lower color difference instrument. The test light source a / B / C / D / F does not mean that the instrument is equipped with these light sources, but that the internal program of the instrument can calculate the color data measured through the led into the color data under the corresponding test light source.

Test light source a
Halogen tungsten filament lamp (incandescent lamp) with relevant color temperature of about 2856K can be used to simulate the lighting of typical homes or stores.

A spectral distribution of standard light source

Test light source B
Direct sunlight with a relevant color temperature of about 4900k.

B spectral distribution of standard light source

Test light source c
The correlation color temperature is about 6800k.

C spectral distribution of standard light source

Test light source D series
It refers to the relative spectral power distribution of sunlight at each time. D series is a large range. For the convenience of practical use, CIE recommends several common light sources such as D50, d55, D65 and d75.
D50, the relevant color temperature is about 5000K, a warm tone light source simulating sunlight, which is often used in the field of printing or pre publishing.
D55, the relevant color temperature is about 5500k.
D65, the relevant color temperature is about 6500k, and the light source with cooler color is a kind of sunlight simulating the blue sky; D65 light source is gradually replaced by D50 light source in European and American countries, but D65 is still one of the standard color temperatures widely used in China.
D75, the relevant color temperature is about 7500k, which simulates the light source of the average sunlight in the north.

D spectral distribution of standard light source

Test light source F series
With the popularity of commercial fluorescent lamps, CIE recommended F series fluorescent light sources.
F1-F6, ordinary fluorescent lamp, in which the typical representative of F2 is cold white fluorescent lamp (CWF).
F7-79, high color rendering fluorescent lamp, where F7 represents wide wave band fluorescent lamp, which is often used as an alternative light source for D65,
F8 stands for wide wave band fluorescent lamp, which is often used as an alternative light source for D50.
F10-f12, three primary color fluorescent lamp, where F11 represents a narrow three band fluorescent lamp, which is usually used for the lighting of office places in Europe or East Asia (tl84).

Spectral distribution of F standard light source

The test light source CWF, i.e. F2 light source, is called differently. The relevant color temperature is about 4150k. It is the light source of American cold white store.
The test light source is u30, the relevant color temperature is about 3000K, and the light source of American warm white store.
The test light source is u35, the relevant color temperature is about 3500K, and the American retailer target specifies the color matching lamp tube.
Test light source tl83, relevant color temperature is about 3000K, European standard warm white store light source.
The test light source tl84, i.e. F11 light source, is called differently. The relevant color temperature is about 4000K, simulating the light source of stores in Europe, Japan and China.

Full band spectral distribution

Color spectrum technology portable color difference instrument adopts full band balanced LED lighting source. The measured color data can be converted into the color data of other light sources through calculation, which is intuitive and fast. Our color difference instrument can also be connected with app and applet, which makes the storage and search of color data more convenient.