Rare earth material long-acting, long afterglow glow in the dark powder is a new type of rare-earth activated strontium aluminate series light-emitting material. It is irradiated in sunlight or light for 5-10 minutes, and the absorbed light energy is quickly transformed into the crystal lattice and stored in the dark. It can also convert energy into light, which can continuously emit light for 8-16 hours. It has stable chemical properties, and the processes of light absorption, light storage, and light emission can be reused. It has a long service life, is non-toxic, and has no radiation.
Rare earth luminous powder is accepted by more and more industries and customers due to its long-lasting and non-radiation characteristics, but the brightness of rare earth long-lasting luminous powder often causes doubts among new customers. The manufacturer said that it could be bright for 10 hours. Why is it invisible for a few hours? It may be thought whether the manufacturer is deceiving or the quality of the product is poor, which may cause some unnecessary misunderstandings. This article briefly analyzes the luminous powder brightness duration.
Generally, the brightness unit of the luminescent material is cd / m2 (candela per square meter), and the brightness of the luminous powder is generally mcd / m2 (milli candela per square meter). Let’s compare the brightness of common light sources at a glance.
The sunlight at noon reaches 10,000 to 100,000 cd / m2. In the daytime, there is usually only 1000 to 5000 cd / m2 indoors, and our night lights are generally 100 to 1000 cd / m2. The brightness of emergency lights is greater than 50 cd / m2. New electroluminescence Signage, the brightness is only 20 ～ 100cd / m2, the maximum brightness of luminous signs made of luminous materials will not exceed 10cd / m2, and the moment the excitation light source is stopped, the brightness is only 1 ～ 2cd / m2 after 2 minutes, one hour The brightness after 0.06 to 0.099 cd / m2, and the brightness after ten hours is 0.006 to 0.01 cd / m2.
Therefore, the brightness of the luminous powder is observed during the day, due to the existence of ambient light (even in a darker dark room, it will exceed 1 cd / m2), but it is a strong contrast between our indoor and outdoor, and our eyes feel very dark. In this environment Observation, luminous materials often do not observe light emission in about an hour.