In order to develop LED lighting technology, developed countries focus on the LED lights features, temperature characteristics and lumen characteristics, test methods, and try to establish test methods and technical standards of the whole set of LED. LED test has been walking in the forefront of the world.
Different applications determines the performance requirements of LED lighting products. From the point of view of optical performance, the LEDs for display, and more attention to the luminous flux, spatial distribution of the beam, the parameters of color, the color rendering properties, and biological application of LED panel is more concerned about the parameters of the biological effective radiated power, the effective irradiates. About its quality, it must be a comprehensive evaluation of many aspects of optical, electrical and thermal.
From the current structure and industrial development of LED lighting products, LED lighting products mainly consider several parameters of the optical properties, electrical properties, thermal properties, radiation safety and lifespan.
Optical properties: the optical performance of LED are mainly related to the performance requirements of the spectrum, brightness, and chroma. According to new industry standards set by “the semiconductor light-emitting diode test method “, the main parameters are peak wavelength, spectral radiation bandwidth, axial luminous intensity, the beam angle of half intensity, luminous flux, radiant flux, luminous efficiency, aromaticity coordinates, color temperature, color purity and dominant wavelength and color rendering index. The display LED are mainly visual effects, so the correlated color temperature and color rendering index is not required. and the white LED lighting, these two parameters is particularly important. It is an important indicator of lighting atmosphere and the effect, while the color purity and dominant wavelength is generally not required.
Electrical properties: LED’s are PN junction electrical characteristics, and it determines the electrical properties of LED lighting products applications, that is one-way non-linear electrical properties, low-voltage drive, as well as sensitive to static electricity and other characteristics. The main measurement parameters include the forward drive current, forward voltage drop and reverse leakage current, reverse breakdown voltage and electrostatic sensitivity.
Thermal performance: lighting with LED luminous efficiency and power is one of the key issues in the development of LED industry, at the same time, LED PN junction temperature and shell heat issues is particularly important, generally with thermal resistance, junction temperature and other parameters.