How to choose integrating sphere?

Integrating sphere is an important tool for luminaire test, it provides good and stable environment during the test, a right integrating sphere will greatly improve the accuracy of the test result. And the following knowledges will help to choose a right integrating sphere.

1. Different coating has different reflectance, normally, AR Ba2SO4 is widely used by most suppliers, but user also can select other coatings accordingly, the details as below:

2.The test mode will greatly affect the test result of luminous flux. According to LM-79 clause 9.2.2, 2π and 4π structures are applied to different lamps.4π structure means the lamp under test is mounted in the center of the sphere, 2π structure means the lamp under test is mounted in the surface of the sphere. Generally, the relationship between lamps and test modes as below:

Usually, 2π test mode is applied to downlight, spotlight, ceiling light and floodlight; and 4π test mode is applied to bulb, corn light, candle light and tube. The position of the lamps will greatly influence the test result of the luminous flux, the error may reach 20% to 30%,   but for colorimetric test, the effect is small.

3.The power and size of the lamp will affect the size of integrating sphere. According to LM-79, for panel type lamp, the catercorner of the lamp should less than 1/7 diameter of the sphere. For linear type lamp, the length of the lamp should less than 2/3 diameter of the lamp. But for the high power lamps, the larger integrating sphere will be better.

The integrating sphere works with spectroradiometer can test the luminous flux, spectrum, color temperature, color rending index, wavelength, chromaticity coordinates and other photometric and colorimetric parameters, Pego can provide test solutions for different users.