For lighting purpose, the luminaries playing a important role. A good lighting design is achieved by the choice of appropriate luminaries. The nature of the light emitted by the lamp and light control depend on the type of light source, the lamp reflection and the transmitting system and various dimming devices etc. It mainly reflects in the distribution curve of lamps. Light distribution curve is actually shows how a lamp or light source distributes the light in space. It can record luminous flux, the quantity of light sources, power, power factor, the lamp size, lamp efficiency and other information including lighting manufacturers, models. What’s more is to record the luminous intensity of lamps in all directions. In order to understand the specific performance of the lamp, we must adopt scientific testing methods. We can only obtain lamp’s accurate results of luminous curve and distribution photometric characteristics by selecting the appropriate testing equipment. The test of lamps luminous distribution is the key to quality control of lighting and lighting design.
The basic principle of luminous distribution measurements: mounting a photometric detector in the location of a certain distance from the center of measured light. Light signal will be processed by the detector in accordance with a relationship after entered the photo detector, then we can obtain the value of luminous intensity or illuminance of the incident light signal. By a variable-angle measuring device which can move in both directions, we can make various luminous curves and charts. The principle of realizing the total flux of the lamp can be divided into luminous intensity integral method and luminous intensity integral method. The principle expressions are as follows: