Evaluate the harm of LED lighting products to retinal blue light, desktop illuminance and illuminance uniformity, lamp flicker (also known as stroboscopic), lamp power factor, noise when lamps are used, and lamp luminous color consistency (technical term is chromaticity tolerance ≤ 5DCM).
The certification and evaluation system of healthy lighting level is formulated by key indicators such as the authenticity of the color of the object when using lamps (called color rendering index R 1-R 15 in technical terms) and the similarity with D40 full spectrum (the closer to natural light).
The state has clear standards for eye protection lighting, with national A-level and highest AA-level. The main difference between country A and country AA is the different illumination. The illumination of country AA is about twice the standard of country A.. According to the relevant policies and regulations, the national A-level illumination is above 250lx within the fan-shaped range with the center of the circle as the radius of 300 mm..
The national AA level illumination is above 500lx. Although the A-class eye protection lamp has reached the national standard, from the point of view of eye health, it is best for everyone to choose AA-class eye protection lamp, but AA-class eye protection lamp is relatively expensive. According to the relevant requirements of building interior lighting design standard, the illumination of desk lamp is required to be above 500lx.
Desk lamps mainly provide local lighting, and two aspects should be paid special attention to when using:
1. The brightness and uniformity of the light in the irradiated area should conform to the actual eye conditions, which is especially important for long-term and short-distance eyes. It should be pointed out that different eye conditions have different requirements for the brightness and uniformity of light in the target area, and there are detailed numerical provisions in the national standard.
However, the types, powers and shapes of light sources and lampshades used in table lamps are quite different, so it is difficult to control the actual brightness and uniformity of the target area. For the brightness and uniformity of light, because general visual inspection is subjective and has large deviation. Therefore, when adjusting the light, we should use the brightness monitoring tools such as eye protection pen.
2. Avoid the glare of the lamp holder and the reflection of the illuminated surface, which are obviously harmful to the eyes.
After turning on the light, first adjust the height of the lamp holder to make the brightness of the target area roughly appropriate; Then fine-tune the illumination angle of the lamp holder, and improve the light uniformity of the target area through visual inspection, without glare and reflection.
When measured with a photometric pen, if the central position of the irradiated area and the brightness level of the light at the front, rear, left and right edges are basically the same, then the light uniformity in this area is good.