The LED spectrometer is used to detect the CCT (correlated color temperature), CRI (color rendering index), LUX (illuminance), and λP (main peak wavelength) of the LED light source, and can display the relative power spectrum distribution graph, CIE 1931 x,y chromaticity coordinate graph, CIE1976 u',v' coordinate map.
The integrating sphere is a cavity sphere coated with a white diffuse reflection material on the inner wall, also known as a photometric sphere, a luminous sphere, etc. One or several window holes are opened on the spherical wall, which are used as light inlet holes and receiving holes for placing light receiving devices. The inner wall of the integrating sphere should be a good spherical surface, and it is usually required that the deviation from the ideal spherical surface should not be greater than 0.2% of the inner diameter. The inner wall of the ball is coated with an ideal diffuse reflection material, that is, a material with a diffuse reflection coefficient close to 1. Commonly used materials are magnesium oxide or barium sulfate. After mixing it with a colloidal adhesive, spray it on the inner wall. The spectral reflectance of the magnesium oxide coating in the visible spectrum is above 99%. In this way, the light entering the integrating sphere is reflected multiple times by the inner wall coating to form a uniform illuminance on the inner wall. In order to obtain higher measurement accuracy, the opening ratio of the integrating sphere should be as small as possible. The opening ratio is defined as the ratio of the area of the sphere at the opening of the integrating sphere to the area of the entire inner wall of the sphere.
Post time: Aug-04-2021