Talking about the test standards and schemes for the life of LED lamps

Standards and test methods are critical to the success of any new technology. Not only because they ensure safety, but also because they can achieve industry consensus and level the playing field by achieving consistency in identifying product performance. The lack of standards and testing methods will confuse all participants, and it has always been one of the bottlenecks in the development of the LED industry. An important reason why LED products are currently favored is their energy saving and life factors, energy saving is very easy to see, and the life test has always been deeply confusing to the industry. Due to the lack of standards, LED products claiming 50,000 or even 100,000 hours are often seen in the market. Currently, the American Institute of Lighting Engineering (IES), the Electric Manufacturers Association (NEMA), the National Standards Lighting Group (ANSLG), the American National Standards Institute (ANSI), the National Institute of Standards and Technology (NIST), Underwriters Laboratories (UL), the International Electrotechnical Commission (IEC), the International Commission on Illumination (CIE), and the Canadian Standards Association (CSA) have advanced the development of standards.
One of the most important recent developments in standards has been the publication of the IES TM-21 document. This is a test method developed by the Technical Committee of the American Society of Lighting Engineering after years of hard work. TM-21 can infer the lumen maintenance rate of LED products, that is, the amount of light output of the LED after lighting up for different times. TM-21 is very important, its importance is reflected in: LED life may exceed 50,000 hours, much longer than traditional lighting, has been tested to the end is impractical, because it is too long, and is likely to be eliminated during its lifetime, and LED will not be directly extinguished like other light sources, LED light decay is very slow, where is the "death point" of LED, is still a topic of discussion.
To better understand the importance of TM-21, let's review LM-79 and LM-80. LM-79 is a method for electrical and photometric measurement of LED products with integrated control circuitry and heat sink, covering the measurement of total luminous flux, electrical power, power efficiency, chromaticity and luminance distribution. The initial performance of the whole lamp can be calculated from the LM-79. However, LM-79 does not involve the measurement of product reliability and life. The LM-80 tests the lumen maintenance of LED packages, arrays and modules at different temperatures, with a minimum of 6,000 hours, with 10,000 hours recommended for every 1,000 hours. But even 10 000 hours of testing is far from the claimed life of most LED products on the market. The TM-21 is important because it can estimate the maintenance of lumens after different periods of light in a relatively small test time, filling a gap in an important performance test. However, TM-21 only covers the testing of LED packages, arrays and modules, and other components can also affect the life of the luminaire, such as drive, thermal management and packaging, which would only make more sense if these were taken into account. But it is undeniable that the TM-21 is already a very big advance.