The measurement of luminous flux requires specialized instruments, and our company uses a comprehensive analyzer for light, color, and electricity, commonly known as an integrating sphere. Can detect lamp luminous flux, luminous efficiency, radiant flux, color temperature, and color rendering index. The volume of the integrating sphere varies greatly

What is an integrating ball tester

The integrating sphere tester is a hollow sphere with a white diffuse reflection material coated on its inner wall, also known as a photometric sphere, luminous sphere, etc. Coat the inner wall of the ball with an ideal diffuse reflection material, which has a diffuse reflection coefficient close to 1. The commonly used materials are magnesium oxide or barium sulfate, which are mixed evenly with a glue adhesive and sprayed onto the inner wall.

2. Principle of Integral Sphere Tester

After the light is incident through the input hole, it is uniformly reflected and diffused inside the sphere, so the light obtained through the output hole is a fairly uniform diffused beam. Moreover, the incident angle, spatial distribution, and polarization of the incident light will not affect the intensity and uniformity of the output beam. Also, because the light passes through the integration inside the integrating sphere tester before being emitted, the integrating sphere tester can also be used as a light intensity attenuator. The ratio of output intensity to input intensity is approximately: the area of the light output hole divided by the surface area inside the integrating sphere tester.

3. The function of the integrating sphere tester

(1) Light receiving

The measured light enters the sphere through the small hole on the integrating sphere tester, and one or two photodetectors are installed on the inner wall. The photocurrent output by the photodetectors is proportional to the illuminance on the inner wall of the integrating sphere tester. In this way, the change in luminous flux entering the integrating sphere tester can be determined based on the change in output photocurrent.

(2) Uniformly illuminated surface

On the inner wall of the integrating sphere tester, several light bulbs (usually four or six) are symmetrically and uniformly arranged with the light outlet hole. The light emitted by the bulb is diffusely reflected multiple times by the inner wall to form a uniform and bright luminous sphere. This integrating sphere tester is used for measuring the vignetting coefficient and image plane illumination uniformity of photographic objectives.

(3) Spherical collimator

The integrating sphere tester with a collimating objective, a light bulb, and black and white plugs is called a spherical collimator, which is used to measure the stray light coefficient of the telescope. When measuring, the illuminance of the blackbody target image and the "white plug" image are measured separately by the photodetector, which is the corresponding indication value measured by the photodetector. After calculation, the stray light coefficient of the tested telescope can be obtained. Because if the imaging of a blackbody target in a bright sky by a telescope is not completely black, it means that in addition to imaging the target, the telescope also has stray light shining on the image plane.   

Integral sphere testing items: electrical parameters: voltage, frequency, current, power, power factor; Light parameters: luminous flux, luminous efficiency; Color parameters: Color Temperature (CCT), Display Finger (Ra, R9), Color Coordinates

Common testing standards for lighting fixtures:

● EN60598-1. EN60598-2-X. EN61347-1. EN61347-2-X EN62560, EN62776, EN62493, EN62471, IEC/TR 62778. EN62031 

●GB7000.1. GB7000.X,  GB19510.1 GB19510.X, GB17625. GB24819 

● UL1993. UL8750. UL1598. UL1310. UL1012. UL153. UL1598C. UL1574. UL962. UL2108. UL588. UL2388. UL1786,

●LM79LM80. AS/NZS4665. GB20943, Lamp 2.0, Luminaries 2.0,DLC 4.2