(CFLs) and fluorescent tubes. Engineers often compare different manufacturer of LED lamps and lanterns, choose the best design. But how do you ensure that the lamps and lanterns of engineers to choose the most suitable?

The LED test manual guide

Illuminating engineering society (IES) is a non-profit organization, publications for lighting applications and scientific reference. Is also the ASHRAE/IESStandard90.1 and Standard189 partnership sponsored institutions. The association has published many lighting, energy related files.

IES have many LED related manuals, can help engineer to clearly identify the authenticity of LED lamps and lanterns is good or bad quality. Among them a handbook for LEDLUMENS - 79-08 electricalandphotometric, LED products made to order a set of test standard procedure. Manual details the test number of lumens, luminous power, intensity of illumination (candle light), lighting direction, color warm color rendering index method (but limited to the LED lamps and lanterns, does not contain the LED chip, package and module.)

LM - 79-08 set in the manual test environment and the changes of parameters, such as environmental temperature, but also record every LED lighting products, related testing data, such as testing agencies, after the inspection date and lighting performance data, if not necessarily can also retain the uncertainty that statement.

Lighting power units of account per watt generated by the number of lumens (light). Over the past few years, LED power continuously improve, from produce 50 lumen to today's 130 lumens per watt. Usually cold white LED than warm white LED to run more efficiently. In contrast, the power of traditional lamps and lanterns are low. Bai Zhi produce 15 lumens per watt bulb, CFL 60 lumens per watt, fluorescent tubes to produce 100 lumens per watt, and high-end metal halogen lamp produces 100 lumens per watt.

LED increases its power in recent years, forecast soon produces 100 lumens per watt LED lamps and lanterns will be pervasive in around. And researchers in the lab has been successful to produce more than 200 lumens per watt LED bulbs. Cree LEDinside points out, than the recent U.S. companies, has announced the commercialisation of 170 lumens per watt LED bulbs prototype, is working with the industry to discuss the actual production time and quantity.

The life cycle

LED lamps and lanterns of a long service life. Same with the other light bulbs, LED lights will also be time to gradually reduce the light output. But is different from other kinds of light bulbs, LED bulbs will gradually darken rather than direct burn out, does not like other bulbs would suddenly broken directly. Improper temperature, power, and water vapor is the main cause of the LED damage, also LED the life of the decision.

IES have another special about the LED light source and the module handbook - LUMENS - 80-08 measuringlumenmaintenanceofledlightsources, formulate a set of testing LED the life of the program (and the light dimmed the periods of up to the elimination).

LED the life of the power number dropped to a certain threshold by the number of hours to decide, this is also called lumen maintenance ratio.

LM - 80-08 manual mentioned in the industry adopted by the two different standards, a lamp lumens for less than 70% of the original and is not suitable to continue to use, the other provisions of lumen number less than 50% of the original is no longer used. The first standard (L70) is mainly adopted by the general lighting of LED lamps and lanterns, the second standard (L50) is a decorative LED lamps and lanterns USES. The two LED life standard is by the lighting research center of solid-state illumination systems and technologies alliance group (ASSIST).

, for example, a LM - 80-08 tests LED lamps and lanterns and declared by detecting the LED samples using more than 30000 hours later, the number of lumens is still higher than the original light output 70%, this means that by LM80 but not droop of agreement on the basic requirements, and even better performance. LEDinside, points out that the current market of LM80 test project, cost is very high, about $15000, the reason is to light thousands of hours to prepare droop test parameters and accurate data, to be able to spend money to do manufacturers, general is above medium, large companies to give priority to.

LED life aspects, LM - 80-08 formulated the standard test environment and variable parameters. Test report should cover important data and test process.

A typical Bai Zhi lamp life 1000 hours; CFL is 8000 to 10000 hours; The best fluorescent lamp is up to 30000 hours. General metal halogen lamp with average life expectancy of 7500 to 20000 hours (life standard adopts L50), while the LED lamp life for 30000 to 50000 hours (life standard adopts L70).

LM - 80-08 did not provide estimates LED the life of the method. IES in the technical memorandum - TM - 21-11 projectinglongtermlumenmaintenanceofledlightsources advice from LM - 80-08 in the process of testing data to calculate the retention of the LED light source. This memo is used to estimate the LED light source to maintain rate and over 6000 hours of life. IESLUMENS - 80 manual specified in three different kinds of testing environment temperature. While TM - 21 estimates of the LED light source can be based on three kinds of test result retention.

Verification and testing

Engineers should be based on IES guide policy LUMENS - 79-08 and LUMENS - 79-08 confirm that LED manufacturers light really by testing standards. Manufacturer of lamps and lanterns should be in accordance with the IESTM - 21 as a benchmark, provide lumen maintenance ratio data. Is the ideal case, please just have the reputation of a third party qualified laboratory testing of LED lamps and lanterns.

Engineers should offer the LED manufacturer requires IESLUMENS - 79-08 and LUMENS - 79-08 detection process data and test results assessment report. Data should be released and the LED specification. And the engineer should also find out the lamps and lanterns manufacturer credit and history.

New products by LM - 80 test is helpful, but detection time may take longer, because the complete detection process take 6000 hours, it is also a LM80 test of the main causes of high prices.