LED Detection Methods and Standards

 

  In recent years, developed countries and government organizations such as the United States, Japan, and Europe have invested a large amount of manpower and material resources in LED lighting to develop and research, so that the technical level of LED light sources has been greatly improved, and the power of single chip has reached 3 watts, luminous efficiency of 30 lumens per watt (1m), single integrated high-power LED chip power has reached 200 watts, making the LED lighting source becomes possible.

 

  LED lighting fixtures consist of LED light sources, electrical accessories and appliances. It uses a semiconductor light emitting device as a light source, has a small size, long life, low energy consumption, instant start, rich colors and other characteristics, is an environmentally friendly and energy-saving cold light source.

  LED products will become the latest energy-saving lighting products. However, LED lighting fixtures are high-tech and high-value-added products. In the past, the research on LED lighting in China was still very weak, and it was very different from the level of foreign countries. In particular, research on the basis of application could not meet the needs of China's industrial development. In the LED lighting product testing technology and product standards are also far from meeting the requirements of China's LED lighting industry development.

 

  In the development of LED lighting in China, we should first establish and improve the technical standards and test method evaluation system for LED lighting fixtures in China, and standardize the existing detection systems so that products of different companies can be tested according to a unified test method. Only in this way can we truly understand China's LED. The technical level of lighting products, in turn, promotes the technical progress of China's LED lighting industry and promotes the accelerated development of the industry.

 

  First, the status of lighting LED standards and detection technology

 

  Both the International Commission on Illumination (CIE) and the International Electrotechnical Commission (IEC) do not have a standard for lighting LEDs.

 

  In the 1990s, CIE published a technical report on general LED testing methods. However, due to the rapid development of LED technology in recent years, many of the technical features of LEDs that have been discovered are not considered in the past. Therefore, at the IEC annual meeting held in 1999 in Kyoto, Japan, representatives of developed countries proposed that IECTC34 (Lighting Technical Committee) establish standards for white LED lighting fixtures, and the Japanese delegation also submitted two draft standards for white LEDs for general illumination. .

 

  In order to develop lighting LEDs, developed countries attach great importance to the research of LED testing methods and standards. For example, the United States National Institute of Standards and Testing (NIST) is a world-famous testing and research institution. At present, they organize internationally renowned test experts to conduct LED test research, focusing on the test methods of LED light emission characteristics, temperature characteristics, and light decay characteristics, and try to establish a complete set of LED test methods and technical standards have led the world in LED testing. Japan established the "White LED Test and Research Committee" to study the test methods and technical standards for white LEDs used in lighting.

 

  In order to seize the commanding heights of LED research, the developed countries in the world have invested a lot of manpower and material resources in LED standards and testing. In terms of standards, they focus on selecting LED characteristic parameters and testing methods. Currently, there are no LED lighting fixture standards in our country, and there is no corresponding LED lighting detection system. Some companies purchased some testing equipment. However, due to the lack of professional research, the level of detection is low, the instrument matching is poor, the detection accuracy is low, and they are not comparable to each other. Test items cannot meet the needs. Although China's professional inspection agencies have also conducted some LED test research, due to limited conditions, a complete inspection and evaluation system cannot be formed, and its level is still far behind that of developed countries.

 

  At present, China's relevant testing departments have begun to carry out research on lighting LED testing methods, including the development of testing equipment. The National Lighting Standardization Technical Committee has included the lighting LED technical standards and test method standards in the standard work plan for 2004, hoping to promote the development of LED technology and application in the lighting field through the formulation of lighting LED standards.

 

  Second, problems that need to be solved urgently

 

  LED lighting technology standards focus on solving the problem of product characteristics and test methods. The most important performance indicators of LEDs are optical and electrical characteristics. Optical properties include luminous flux, light distribution, brightness, spectral distribution, chromaticity coordinates, color rendering index, and the like.

 

  LED is used in lighting fixtures, both optically similar to the common common light source, but also the specificity of its products: LED is a directional light-emitting device; light body is small, can be approximated point light source; luminous environment and processing The process has a greater impact.

 

  The measurement period of LED light decay characteristics is very long (tens of thousands or even tens of thousands of hours). In addition to the optical performance of the LED in use, there are characteristics of its electrical accessories (including energy-saving electrical accessories), mechanical characteristics, temperature characteristics and appliance safety characteristics. Therefore, the problem of test methods must be considered in the formulation of standards.

 

  The first is to select and use test equipment that conforms to the characteristics of the LED and establish a test system. Including: LED optical test system, temperature monitoring test system, electrical test system, environmental test system, durability reliability test system, etc. Among them, the main test system should adopt international advanced methods, and the test methods should be able to approach the international advanced level.

 

  Through the cooperation and exchange with foreign laboratories, China's LED detection technology is synchronized with international development, so that the standard can objectively reflect the technical level of China's lighting LED, adapt to the rapid development of China's lighting LED, and can be consistent with the international level , further promote the development of LED technology.

 

  Third, lighting LED standard series of standards

 

  The basic standard (or main standard) in the series of standards is the single-tube LED lighting standard and test method standard. On this basis, a standard system of lighting LED is formed. The LED standard firstly needs to solve the characteristic requirements of the LED light source in lighting, determine the technical requirements of the LED light source, and find the main technical characteristics and technical parameters of the LED through the detection of the LED to determine the technical level of the LED lighting in China and related technical indicators. skills requirement.

 

  Due to the rapid development of lighting LED technology, the development of lighting LED standards should be compatible with the development of technology and the needs of the market. Standardization agencies, testing agencies, lighting LED research departments, production companies and application units should cooperate with each other and work together to establish a set of national standards for lighting LED in line with China's national conditions and advanced technology.