Knowledge of LED lamps, common sense of LED lamps
1. Luminous flux: The total amount of visible light emitted by the light source per second, which is simply the amount of light emitted. Unit: Lumen (lm)
2. Illuminance: The incident luminous flux per unit area, that is, the value obtained by dividing the luminous flux by the area. Unit: Lux. Illumination is divided into horizontal illuminance and vertical illuminance. The horizontal illuminance is the illuminance of the luminous flux incident on the horizontal surface, and the vertical illuminance is the illuminance of the luminous flux incident on the vertical surface.
3. Light intensity: symbol I, unit candela mcd, indicating the luminous flux emitted by the luminous body within a unit solid angle in a specific direction
4. Luminance: Symbol L, unit Nit cd/m2, indicating the luminous flux per unit solid angle per unit area of the luminous body in a specific direction
5. Luminous efficiency: the unit is lumens per watt, Lm/w, indicating the ability of an electric light source to convert electrical energy into light, expressed by dividing the emitted luminous flux by the power consumption
6. Average life: unit hour, description refers to the number of hours when a batch of bulbs to 50% of the quantity is damaged
7. Economic life: unit hour, indicating that the integrated beam output is reduced to a specific number of hours when the damage of the bulb and the attenuation of the beam output are considered at the same time. This ratio is 70% for outdoor light sources, and 80% for indoor light sources such as fluorescent lamps.
8. Color temperature: expressed in absolute temperature K, that is, heating a standard black body. When the temperature rises to a certain level, the color starts to change from dark red to light red to orange to white to blue. When the color of a light source is the same as that of the black body , We call the absolute temperature of the black body at that time the color temperature of the light source. The color temperature is in the middle of 3000-6000K, and people have no particularly obvious visual psychological effects under this hue, and there is a refreshing feeling; therefore, it is called "neutral" color temperature.
9. The color temperature of the light source is different, and the light color is also different:
10. The color temperature is below 3300K, and the light color is reddish to give a warm feeling; there is a stable atmosphere and a warm feeling;
11. Color temperature and brightness Under the illumination of high color temperature light source, if the brightness is not high, it will give people a kind of cloudy atmosphere; under the illumination of low color temperature light source, the brightness will be too high and people will have a stuffy feeling.
12. Contrast of light color Using two light sources with large light color difference in the same space, the contrast will have a gradation effect. When the light color contrast is large, the brightness level can be obtained while the light color level is obtained.
A The high color temperature light source illuminates, making the object feel cold.
b The color temperature light source illuminates, so that the blue has a cool feeling
c The low color temperature light source can make the red more vivid;
13. Color rendering: The degree to which the light source presents the color of the object itself is called color rendering, that is, the degree of color fidelity; the color rendering of the light source is indicated by the color rendering index, which indicates that the color of the object under the light is better than the reference light (Sunlight) The deviation of the color during lighting can more fully reflect the color characteristics of the light source. Light sources with high color rendering have better color performance, and the colors we see are close to natural colors. Light sources with low color rendering have poor color performance, and the color deviations we see are also larger. The International Commission of Illumination CIE sets the color rendering index of the sun as 100. The color rendering index of various light sources is different, such as: high pressure sodium lamp color rendering index Ra=23, fluorescent tube color rendering index Ra=60~90.
Faithful color rendering: A light source with a high color rendering index (Ra) must be used to correctly express the original color of the material, and its value is close to 100, which has the best color rendering.
14. Luminous efficiency: An important indicator to measure the energy saving of a light source is the luminous flux emitted by the light source divided by the power consumed by the light source. Unit: Lumen/Watt (lm/w). This is an important indicator of the quality of lighting fixtures.
15. Glare: There are extremely bright objects or strong brightness contrast in the field of view, which can cause visual discomfort called glare. Glare is divided into disability glare and uncomfortable glare. Glare is an important factor that affects the quality of lighting.
16. Electromagnetic interference: The gas discharge lamp ballast will interfere with surrounding electrical appliances through radiation, conduction, etc. during use.
17. Electromagnetic noise: It may make the surrounding electrical appliances work abnormally or even out of control.
18. Average life: the time when the lamp is 50% damaged.
High contrast: The ratio of the difference between the brightness of the recognized object and its background to the background brightness is called brightness contrast, and the contrast affects the visibility of the object. Objects with large contrast are easy to be observed and produce a sense of closeness and excitement visually.
Effect color rendering: To clearly emphasize a specific color, and express the beauty of life, you can use additive color to enhance the color rendering effect.
The color temperature exceeds 6000K, and the light color is bluish, giving people a cool feeling
