Method for measuring optical properties of LED

Since the light emitting diode can mass production, a variety of color brightness (LED) since it is necessary to accurately measure its optical properties. LED measurement using two methods: photometry and radiometry. Photometric measurements are limited to visible light, such as the response of the human eye. Radiometric measurements are not limited by the human eye. The two methods can be used to describe the radiation power and luminous intensity of LED. The radiated power is all the power (flux) of the LED in any direction. The luminous intensity is the direction of the observer in the direction of each unit of the three-dimensional angle of radiation to the object's luminous flux, often considered to be along the axis of the LED, the unit is Candela. Because the shape size of LED luminous surface is unique, it is difficult to lead to the luminous uniformity, measurement standard has not been well regulated. So careful consideration of the design and use of LED test equipment is essential for accurate completion of LED testing. The easiest and most convenient way to measure the total flux of LED is to use the integrating sphere and the Avantes spectrometer. For optical radiation measurement, integrating sphere is a very simple element. The inner surface of the integrating sphere has perfect scattering, and the light is even reflected on its inner surface. The radiation of the light on the inner surface is very uniform after many reflections, resulting in the same degree of light radiation on any point of the sphere wall. The system can be used for scaling AvaLight-HAL-CAL-ISP halogen lamp calibration. The other parameters can be calculated from the measured spectral distribution by AvaSoft-IRRAD spectrometer software, and the absolute radiation measurement can also be carried out. You can also calculate, display and storage by light intensity, unit for Watt/cm2/nm. In addition, in a separate window can display up to 10 optical parameters: the amount of radiation Watt/cm2, Joule/cm2, Watt or Joule, photometric Lux or Lumen; Y, Z color coordinates X, x, y, Z, u, V and color.