Misunderstanding 1, the actual life expectancy is too high.
LED manufacturers expect LED life to reach 100,000 hours MTBF (average trouble-free time, the standard used by traditional lighting manufacturers to measure light source life). However, like all basic light sources, the luminous flux of the LED also fades with time. So, although the LED light-emitting time can be very long, but not the only consideration to determine the service life. The attenuation of LED lumens is affected by many environmental conditions such as ambient temperature, humidity and ventilation. Lumen attenuation is also affected by control, thermal management, current levels and many other electrical design considerations.
Many Purchasing Guide in the promotion of LED for some reason may give customers some fuzzy information, resulting in misleading. As a light source of lighting, the brightness of the lamp has a gradual decay of the process of darkening (such as fluorescent lamps, energy-saving lamps), this process referred to as light failure. Therefore, consumers in the purchase of LED to pay attention to its decline in light speed, rather than the use of time, consumers do not expect the actual life expectancy is too high.
Misunderstanding 2, the actual angle of light as an effective angle.
LED light angle is divided into effective angle and the actual light angle. The luminous intensity value is half the direction of the axial intensity and the direction of the light-emitting axial (normal) is the effective angle. Half of the half angle of the angle (or half power angle) is the actual light angle. In the axial strength of half the angle because the light is too weak in the practical application does not count the effective angle.
Therefore, consumers in the purchase of products should pay attention to the actual light angle of the product, calculate the number of products used in the project, the actual light angle prevail, effective light angle can only be used as a reference value.
Misunderstanding 3, the greater the power the higher the brightness.
The brightness of the LED is measured by the luminous intensity. The luminous intensity refers to the luminous intensity in the direction of the normal (for the cylindrical arc tube), that is, the luminous flux emitted by the unit solid angle, in candlelight (Candela, cd). As the general luminous intensity of LED is small, so the luminous intensity commonly used in Mendra (mcd) as a unit. In general, the light source will be different directions to different intensity of its luminous flux, in a specific direction of the unit angle generated by the visible light radiation intensity is called light intensity, referred to as axial brightness.
From the force in the same time to do the power of the number of the introduction of the concept of electric power, the current work fast, electric power is large; current work slow, electric power is small, or in the same time, the more power to do more power, On the LED, not the greater the power, the higher the brightness of the product. Therefore, consumers in the purchase of LED lamps to pay attention to its axial brightness, rather than power.