Light & Engineering Vol. 23, No. 1, pp. 65-70, 2015 Svetotekhnika No. 5, 2014, pp. 53-57 RESEARCH INTO THERMAL OPERATING MODES OF A STREET LUMINAIRE WITH LIGHT EMITTING DIODES USING THE IR THERMOGRAPHY METHOD Vladimir N. Letushko, Mikhail I. Nizovtsev, and Alexei N. Sterlyagov The Institute of Thermophysics of S.S.Kutateladze of the Siberian Branch of the Russian Academy of Science, Novosibirsk E-mail: sterlyagov@itp.nsc.ru ABSTRACT The article is dedicated to experimental research of the thermal mode of a street luminaire with light emitting diodes (LED). <...> The IR thermography method was used to obtain data on temperature time dependence on the light-emitting diode matrix (LEDM) surface. <...> Based on the thermogram analysis, the warming-up speed and maximum temperatures of the LEDM surface were determined. <...> The data collected on the thermal operating mode study of a street luminaire with LEDs using contact measurements of temperature and density of the thermal fl ow are also presented. <...> Keywords: LEDM, IR thermography, surface temperature, thermal fl ow density, thermal mode It is well known that one of basic causes of premature LED failure and decreasing service life is overheating as a result of not observing the proper thermal mode. <...> Therefore, the issue of the LED thermal mode determination in lighting devices during the operation process is important. <...> In order to reveal local places of the LEDM overheating, we need to know the temperature distribution across their surface. <...> A spatial analysis of LED temperature fi elds is possible when processing their spectral characteristics obtained by scanning by the area [2], but this meth65 od is complex due to the required hardware and demands a long measurement period. <...> The IR thermography method opens up a wide range of opportunities for experimental research of temperature fi elds across the LEDM surface [3, 4]. <...> Its advantage is an immediate temperature distribution recording across the surface and a dynamic understanding of the correspondent thermal process. <...> Some results of experimental research of the thermal mode of a street luminaire with LEDs (and more specifi cally – with LEDMs) and some results of temperature measurement across LEDM surface are presented in this paper. <...> The LEDMs were fi xed on a duralumin <...>