Color luminous powder luminescence time analysis

Regarding the brightening time of colored luminous powder, it is not a customer reaction. It is obvious that the manufacturer can see that it can be illuminated for 10 hours. It may not be seen for several hours. It may cause some unnecessary misunderstandings. We verify by direct comparison method. under:

    Usually the unit of brightness of the luminescent material is cd/m2 (candela per square meter), and the brightness of the luminescent powder is generally mcd/m2 (millicandela per square meter), let us compare the brightness of the common light source at a glance.

    It reaches 1~100,000 cd/m2 in the midday sun, and only 1000~5000 cd/m2 in the general indoors during the day.

    The light in our evening is generally 100~1000cd/m2, and the brightness requirement of the emergency light is more than 50cd/m2.

    The new electroluminescent sign has a brightness of only 20~100cd/m2.

    The brightness of our luminous signs made of luminescent powder will not exceed 10cd/m2, and the brightness will be only 1~2cd/m2 after 2 minutes, and the average brightness will be 0.060~0. 0990cd/ after one hour. M2, after ten hours, generally 0. 006 ~ 0. 010 cd / m2. Therefore, the brightness of the luminous powder is observed during the day, due to the presence of ambient light (even in the darker darkroom, it will exceed 1 cd/m2), but because of the strong contrast in the outdoor room, the eyes feel very dark, this environment In the observation, the luminescent powder often does not observe luminescence in about one hour. If you use a drawer or paper tube to observe from the light, then the luminous powder will not be visible for more than 10 minutes. Then why do manufacturers who produce luminescent powder say that they can emit light for 10 hours? The reason is that the light that can be observed under the full dark condition of the human eye is very weak to 0.00032cd/m2, and the brightness of the luminescent powder usually decays below this brightness. The time can reach more than 10,000 minutes, which means that it can continue to illuminate for 10,000 minutes (166.67 hours). In theory, the human eye can still be seen. In order to explain the brightness of the luminescent powder in the image, when the long afterglow luminous powder is promoted in the early stage, it can be said to be able to emit light for 8 hours and 10 hours, etc., and is distinguished from the zinc sulphide luminescent powder which usually can only be continuously illuminated within one hour. In order to accurately express and popularize the application of test instruments, it is now gradually replaced by 1 hour data. Since the cd/m2 unit is large, the luminescent powder is usually mcd/m2 (millicandela per square meter), generally one hour brightness. Both are between 10~100mcd/m2, different grain sizes and product grades are different in brightness. The larger the particle size of the luminescent powder is, the higher the brightness is, and the larger the granularity is, the better the granularity is. Smaller products, the more expensive the price, in order to save material costs, generally use a thicker product to achieve higher product brightness when the process conditions allow.