Lighting quality refers to whether the lighting source meets the lighting indicators such as visual function, visual comfort, safety, and visual beauty.
The correct application of lighting quality indicators will bring a brand new experience to your lighting space, especially in the LED lighting era, where the performance of lighting quality is extremely important. Using lighting quality indicators to buy LED light source products will bring more lighting with less effort. Effects, below, we introduce the main indicators of lighting quality.
1. Color temperature
It is the light color of white light, which distinguishes whether the light color of white light is reddish or bluish. It is expressed by absolute temperature and the unit is K (Kelvin). Usually the color temperature range of indoor lighting is 2800K-6500K.
The most typical lighting white light is sunlight. As we all know, sunlight is a mixture of multiple colors of light. Among them, the most important is the light of red, green and blue.
White light uses the color temperature index to describe the light color. When the white light contains more blue light components, the white light color will be bluish (cold, such as the northern winter sun at noon). When the white light contains more red light components, the white light color will be biased. Red (warmer, such as morning and evening sunlight), color temperature is the only way to express the color of white light.
The white light of artificial light sources is also formed by mixing light of multiple colors. For artificial light sources, we also use color temperature to describe the light color of white light; for the physical analysis of white light, we usually adopt the method of spectral analysis, and the spectral analysis of white light requires special Instrument test production.
2. Color rendering
It is the degree of restoration of the surface color of the illuminated object by the illuminating light source. It is expressed by the color rendering index Ra. Ra ranges from 0-100. The closer the value of Ra is to 100, the higher the color rendering and the better the restoration of the color of the illuminated object surface. The color rendering of the light source requires professional instrument testing.
It can be seen from the solar spectrum that the solar spectrum is the most abundant and the light source with the best color rendering. The color rendering of artificial light sources is always lower than that of sunlight. Therefore, the best way to identify the color rendering of artificial light sources is with The easiest way to compare the sunlight is to compare the color of the palm or face under the sunlight and the artificial light source. The closer to the color under the sunlight, the better the color rendering. You can also look at the palm with the palm facing the light source. If the color of the palm is gray or yellow, the color rendering is not good. If the color of the palm is blood red, the color rendering is normal
3. The illuminance value of the light source
Illuminance is the luminous flux of the light source illuminating a unit area of the illuminated object. It indicates the degree of brightness and darkness of the surface of the illuminated object, expressed in Lux (Lx). The higher the illuminance value of the illuminated surface, the brighter the object is illuminated.
The magnitude of the illuminance value has a lot to do with the distance from the light source to the illuminated object. The farther the distance is, the lower the illuminance value. The illuminance value is also related to the light distribution curve of the lamp. The smaller the light output angle of the lamp, the higher the illuminance value. The greater the light output angle, the lower the illuminance value; the illuminance value needs to be tested by a special instrument.
From a photometric point of view, luminous flux is the main indicator. As a lighting product, it mainly reflects the brightness of the surface of the illuminated object. The illuminance value is used to describe the lighting effect more accurately. The illuminance value of indoor lighting reflects the indoor lighting Brightness and darkness, too high illuminance and too low illuminance have an impact on the health of human eyes
4. The light distribution curve of the lamp
The indoor lighting effect is related to the layout of the lamps and the light distribution curve of the lamps. A good lighting effect is reflected in the reasonable layout of lamps and the correct application of the light distribution of the lamps. The layout of the lamps and the light distribution of the lamps determine the visual function and visual comfort of the indoor lighting, and reflect the three-dimensional sense and layering of the lighting space. Among them, the proper light distribution application of the lamps can improve the lighting quality of the entire lighting space.
The role of lamps is to fix and protect the light source, as well as to decorate and beautify the environment. Another purpose of the lamp is to redistribute the light output of the light source so that the light of the light source outputs light according to the light output angle of the lamp design. This is called the light distribution of the lamp.
The light distribution curve of a lamp describes the light output form of the lamp. The smaller the light distribution angle, the brighter it will make people feel. The light distribution curve of the lamp is tested by a special instrument.
5. The luminous efficiency of the light source
The brightness of a light source is described by luminous flux. The unit of luminous flux is lumens (lm). The greater the luminous flux, the higher the brightness of the light source. The ratio of the luminous flux of the light source to the power consumption of the light source is called the luminous efficiency of the light source, and the unit is lm. /w (lumens per watt)
The luminous efficiency of the light source is an important indicator of the quality of the light source. The higher the luminous efficiency of the light source, the more energy-saving the light source. The luminous efficiency of the LED light source is about 90-130 lm/w, and the luminous efficiency of energy-saving lamps is 48-80 lm/w. The luminous efficiency of incandescent lamps is 9-12 lm/w, and the luminous efficiency of poor quality LED light sources is only 60-80 lm/w. Products with high luminous efficiency have relatively good light source quality.
6. Lamp efficiency
Indoor lighting rarely uses a light source alone. Usually the light source is used in a luminaire. After the light source is placed in the luminaire, the light output of the luminaire is lower than that of a single light source. The ratio of the two is called luminaire efficiency, which is high. , Which shows that the manufacturing quality of lamps is good, and the energy-saving index of lamps is high. Lamp efficiency is an important index to measure the quality of lamps. By comparing the efficiency of lamps, the quality of lamps can also be evaluated indirectly.
The relationship between the luminous efficiency of the light source, the efficiency of the luminaire, and the illuminance value of the luminaire is that the luminous flux output by the luminaire is only proportional to the efficiency of the luminaire, and the luminous intensity value of the luminaire is directly proportional to the luminous efficiency of the light source. The light curve is related.
7, glare
It means the degree of visual discomfort caused by the light of the light source. In layman’s terms, when you feel the light source is dazzling, it means that the light source has glare. On the street at night, when a car with high beam headlights comes oncoming, the dazzling light we see is glare. The glare can make people feel uncomfortable and even cause temporary blindness. The glare of indoor lighting is harmful to children. And the elderly have the greatest impact, and glare affects the quality of lighting, which is a problem worthy of attention.
The glare problem and the energy-saving indicators of indoor illuminance and lighting are mutually restricted. If a single light source is bright enough, there will be glare problems, that is, the so-called “enough light will glare”. The glare problem needs to weigh the pros and cons.
8. Strobe
Light source stroboscopic is a phenomenon in which the brightness of the light source changes with time. When working under a stroboscopic light source for a long time, it will cause visual fatigue. The maximum stroboscopic time of the light source is 0.02 seconds, while the visual stay time of the human eye It is 0.04 seconds.
The stroboscopic time of the light source is faster than the visual dwell time of the human eye, so the human vision can hardly feel the light source flickering, but the visual cells of the human eye will sense it. This is the cause of visual fatigue. The light source flickers The higher the frequency, the lower the visual fatigue caused by the stroboscopic. We call it low-frequency flash. The stroboscopic will unknowingly affect human eye health and affect the quality of lighting.
The strobe of the light source is invisible to the human eye, so how to check it? Here is a simple and effective method to distinguish the strobe of the light source. Use the camera function of the mobile phone to aim at the light source and adjust the appropriate distance. When the screen appears bright and dark Streaks, indicating that the light source has stroboscopic
If the stripe interval is obvious, it means that the light source has a large strobe, and there are obvious light and dark stripes on both sides of the light source, which means that the strobe is large. If the light and dark stripes on the screen are few or very thin, the strobe is low; if the light and dark stripes are hardly visible, It means that the strobe is very low. However, not all mobile phones can see the strobe. Some mobile phones cannot see the strobe. When testing, it is best to use a few more mobile phones to try.
9. The safety of lighting equipment
The safety of lighting equipment includes electric shock problems, leakage problems, high temperature burns, explosion problems, installation reliability, safety signs, application environment signs, etc.
The safety of lighting equipment is restricted by relevant national standards. Generally, we can judge by observing the appearance quality of the product, the certification mark, the process quality of the driving power supply, and the relevant information provided by the product. The easiest way is the price of the lighting product. , High-priced products will have higher relative reliability, and products with too low prices will cause vigilance, that is, the so-called cheap goods are not good.
10. Energy-saving indicators of lighting equipment
The highest level of lighting is visual beauty. In order to enjoy this beauty, the lights will be turned on for a long time to appreciate. If the power consumption of the lighting source is too high, it will cause the user’s psychological burden due to the electricity bill, which will cause the visual beauty to decrease, thereby indirectly reducing Lighting quality, so we include the energy-saving indicators of lighting equipment as lighting quality indicators.
Related to energy-saving indicators of lighting equipment are:
1) The luminous efficiency of the light source.
2), lamp efficiency.
3) The effect design of the lighting space and the reasonableness of the illuminance value of the lighting space.
4), the power efficiency of the drive power supply.
5) The heat dissipation performance of the LED light source.
We emphatically discuss the efficiency of light source driving power and the heat dissipation of LED light sources. For LED light sources, the higher the efficiency of the driving power, the higher the luminous efficiency of the light source, and the more energy-saving the light source. The power source efficiency and the power factor of the power source are two different Both indicators are high, indicating that the quality of the drive power is good.
Post time: Oct-21-2020