Lighting engineering led lights of choose and buy of three big mistakes
the choose and buy of leds is crucial for the whole LED lighting engineering, it relates to the performance of the whole LED lighting engineering eventually form, is in the final can stand the test of time, the whole project surveying of land engineering lighting company are summarized in more than 20 years experience in the process of operation, to share with friends to block in the process of LED lights to choose three big mistakes.
the tunnel lighting scene
a brightness, the greater the power, the higher the
LED the brightness of the measured by luminous intensity, luminous intensity is normal, ) refers to the axis of cylindrical light tubes Direction on the luminous intensity, that is, the luminous flux emitted per unit solid Angle, unit for candle, Candela, cd) 。 As a result of the general LED luminous intensity is small, so the luminous intensity common milli candela ( ' As a unit. In general, the light source will emit the light flux in different directions with different strength, in a specific direction unit solid Angle the visible radiation intensity is called out by the light intensity, hereinafter referred to as the axial intensity.
from the strength of work within the time equal to introduce the concept of electric power and current work fast, electrical power is large; Current work slow, electrical power is small, or in the same time, the more current to do the work, the greater the power, on the LED, not the power, the greater the product the higher brightness. With appropriate beauty electronic three lamp red LED, for example, the axial intensity for 1200 MCD, current is 40 ma, power is zero. 48 w; Three white LED lamp under the same brightness, the current is 18 ma, power is only 0. 24 w; You can see two kinds of light in the power under the same brightness is different. So, consumer is in when LED lamps and lanterns of choose and buy should focus on its axial brightness, rather than power.
the subway lighting scene
2, to the actual service life of expecting too much
LED manufacturers expect LED life of 100000 hours MTBF ( Traditional MTBF, lamps and lanterns manufacturers use the measuring standard of life) 。 But, like all basic lighting, LED the luminous flux of lumen attenuation with time. So, although LED can be a very long time, MTBF is not the only consideration to determine the service life. LED lumen attenuation by many environmental conditions such as temperature, humidity and ventilation effect. Lumen attenuation is under control, thermal management, current levels, and many other electrical design considerations.
when a lot of salesman in pushing the sale of LED for some reason is likely to provide some fuzzy information, misleading, such as the service life of the LED in the 100000 hours, 100000 hours here refers to the manufacturers expect the service life of the LED. But as the light source of the light, the brightness of the lamp has a gradual attenuation dark ( Such as fluorescent lamp, energy-saving lamp) , a process referred to as 'the light failure. So, consumer is when the choose and buy the LED to focus on its speed droop, instead of using time, consumers do not expect too much of actual service life.
factory lighting scene
3, the actual light Angle as Angle
the LED light Angle can be divided into effective Angle and the actual light Angle. Half of luminous intensity value of the axial intensity value direction and optical axis to ( The normal) An Angle of effective point of view. The view of half value Angle of 2 times, Or a power Angle) Is the actual light Angle. Outside the axial intensity half Angle because the light is too weak not included in the perspective of effective in practical application.
therefore, consumers in the choose and buy products should pay attention to product's actual light Angle, products used in the calculation of engineering quantity, will be subject to the actual light Angle, the effective light Angle can be used as a reference only.