How To Build The Darkroom For Goniophotometer?

Goniophotometer is mainly used for light intensity performance measurement of luminaries and light source, which is the photometry value in different directions in space and color distribution. Goniophotometer should run in dark room, and what are the requirements for the test environment?

The size requirements for dark room: for example, such as LISUN LSG-2000 LM-79 Goniophotometer System. According to CIE requirement, dark room consists of 2 parts, the recommended size of the dark room for Goniometric Rotating Console is W5.0m*L5.0m*H5.9m;  the recommended size of the dark room for Photometric Light Path is W1.5m*H1.5m*L(15m – 30m). According to the requirements of CIE, the recommended distance between lamp and photo detector is 6 times than the diameter of lamp. The recommended size of operating room is no less than W3m*L3m. LISUN GROUP engineer dept will submit the Lab Design support documents according to the customer’s real lab size after the formal purchase order was confirmed.

Requirements of eliminating the stray light: the photodetector can only receive the light reflected by the rotating mirror in the LSG-2000 system. The light given off directly by the luminaries and reflected by the wall and floor is warded off by the light fence. Internal surface of the dark room and dark path together with the surface of the light fence should be painted unpolished black or be covered by black cloth and black carpet.

Temperature of the Environment: Because of the thermal performance of LED, the photometric value and electronic performance of SSL products are sensitive to the change of temperature and air movement. Temperature around the lamp or luminaries must be 25℃±1℃ during the test. The temperature should be measured in the distance that is no more than 1m, and measurement height should be the same with the SSL product. Temperature sensor should avoid the direct optical radiation of SSL product and other light source. Therefore, you should place an air conditioner in the dark room to control the temperature around the lamp to reach the temperature requirement of CIE. If the measurement is not doing under the recommended temperature, this is a non-standard condition, which should be remarked in the test report.

Requirements of Airflow: Airflow may be induced by natural aeration, air conditioner or movement of the luminaries in the goniophotometer, but the speed of the airflow couldn’t exceed 0.2m/s. The airflow of the tested lamp surface may greatly change the electric value and photometric value. The testing personnel must not enter the dark room during the test.

Vibration and shock: When the lamp is in lighting, the vibration couldn’t exceed 10m/s2(4~3000Hz), or the moving scope of the lamp couldn’t exceed 30mm (at most 4Hz).

Smoke, Dust and Moisture: The test environment must free from smoke, dust or moisture. At the same time, even not during the measurement, smoke, dust or moisture will also influence the reflectance of the reflecting mirror and induce more stray light. So, the test room must be kept clean, no smoke and dry. The humidity should be less than 60% RH.

Lisun LSG-2000 Moving Mirror Goniophotometer System is widely applied to Luminaries manufacturing enterprise and lab, such as Sharp Electronics in Memphis TN(USA), CS TECH MEXICO, S.A. DE C.V. (Mexico), DORADO Praha s.r.o. (Czech) etc. The reason why Lisun can win some many customers is because we always practice the motto of right products, right price and right service. Lisun will continue feedback good quality products and superior service in the feature.