In LED testing instrument < http://www.semilamp.com > technology, due to the characteristics of the product and the traditional LED light source are quite different. The luminous and "LED temperature have close relations, and in LED products of optical and thephotoelectricity parameter test, the environment temperature, radiator or the change of the temperature change shell LED the junction temperature, thus influence light output. LED lamps in the photometric test, often is the glowing device and lamps shell parts are inseparable, need one test, usually use absolutely photometric measuring method. Some high brightness LED blue light can cause eye retina photochemical damage, according to IEC62471 "the light and the light of the lamp system biological safety" series standard, the damage of LED products when the test, and it is also the key point of the industry. In addition, the LED products have long life characteristics, we can't like normal lighting products for flash point test, must use certain accelerated testing method, the effective life prediction LED products, such as the "energy star" the LM80 standards, our country is rushing the accelerated life testing method standard LED.
Therefore, in recent years on international performance measurement technology and LED products detection equipment is developing rapidly. In China, along with the rapid development of LED industry, detection technology and equipment of innovation ability increased significantly, launched a series of meet the need of advanced testing equipment industry; Especially in LED products of optical and energy efficiency test, the space of the lamps light distribution measurement, the service life of the acceleration test, light biological radiation safety testing and so on, developed with the international competitiveness of advanced testing equipment.
A, LED products of optical and energy efficiency test
In LED products performance test, the temperature control is very important. According to the domestic and foreign relevant standards, LED device general control "shell temperature or hot temperature; For LED module, the control module on the hot temperature of the heat sink; And LED application products, the one with the environment temperature as the benchmark. Therefore, in LED products of optical and energy efficiency in detecting, LED components, modules and in application products, test equipment of temperature control mode is very important.
Some LED products beam directionality is stronger, in the integral goal of measurement, beams projected area, such as the position is more sensitive to block screen, IESNA LM79 standards and CIE127 technical reports are made a provision, the proposal by using the higher than spectral reflection of 1 ball wall coating materials. The United States NIST in facilitating international LED standard standard test method, walk in the front row, test equipment to also put forward the extremely high requirements. Figure 1 of the constant temperature integral ball, zhejiang university is three color for the American company national institute of standards and technology developed NIST standard tests LED facilities for LED components, modules, application products and three kinds of LED products realize constant temperature test.
Second, LED lamp and the space of the lamps light distribution detection
Distribution is a measure of light sources and photometric luminous intensity distribution of space lamps luminosity of measuring equipment. Figure 2 is the international lighting committee CIE70 technical documents of the recommended a reflector distribution photometric principle structure, must always around the center axis rotation, and photometric detector in reflector between can accurately set back stray light aperture, very effectively eliminate stray light. This distribution is suitable for all kinds of complicated by photometric beam spatial light distribution measurement, has been more than one hundred laboratory use, currently use first. China's several national laboratories also adopted the reflector photometric distribution.
In recent years, with the rapid development of LED technology, LED products space light distribution measurement has been more and more domestic and international attention. Compared with the traditional light source and lamps, LED lighting products often exist in the complex beam distribution, may have certain space chromaticity difference, so the space of LED products light distribution measurement puts forward new requirements, not only to test the space of LED light intensity distribution, and at the same time measurement space chromaticity inhomogeneity distribution. In addition, for many laboratory, space restricted the application of high performance equipment, in order to save space, at present our country also developed using two pieces of the distribution of the reflector digested.
Figure 3 tracking reflector type distribution in China is the independent research photometric large photometric test equipment. It from liquid crystal display motion artifact in the measurement of optical tracking measurement as the thought, solve the several circular motion before distribution of the measuring photometric reflector type beam axis is not fixed, suppressing stray light is poor, or photoelectric detector in space and other sports a series of problems. In combination with the rotating central reflector type distribution photometric and circular motion reflector type distribution photometric advantages, measurement of the position of the lamps remain unchanged, measuring beam perpendicular incident detector, the position of the photoelectric detector keep fixed; In the way of measuring light set of multiple away stray light aperture, can almost completely eliminate test room ground, metope and ceiling and stray light reflection to each other. At the same time through the special design of new type high precision chromaticity measuring system, and can realize measured accurately and rapidly LED module or lamps light color space distribution. This distribution test range photometric, cover an area of an area small, high accuracy, meet CIENO. 70, CIE 121 and international standard BS EN13032 measurement requirements.
Three, LED products light biological radiation safety detecting and evaluating
Along with the development of light biology research, ray radiation safety problem more and more cause the attention of people. Especially in recent years the rapid development of LED, chip power and the quantum efficiency greatly raised, high-power blue LED chip has been widely used in ordinary lighting area; High power more integrated chip and secondary optical technology development, make the ray of light is more dangerous LED attention. The human eye retina ray radiation damage security assessment need to measure 300 nm to 700 nm blue light photochemical harmful radiation brightness and 380 nm to 1400 nm retinal hot harmful radiation brightness, and it should accord with the similar to the human eye structure of the measuring conditions, to the testing technology and equipment to set the high requirements. Figure 4 is our country experts in the national institute of standards and technology of the human eye retina based on established NIST radiation brightness millions of L
