SPECTRAL POWER DISTRIBUTION OF LEDS AND POUCH PHOTOMETRY

Abstract

The rapid development of lighting technologies, which has been observed in recent decades, is definitely connected with the widespread introduction of LED light sources. At the same time, if in the early days the energy efficiency of LEDs was noted, now the use of certain spectral characteristics of such sources is on the agenda. At the same time, methods and means of photometry are expanding, in addition to photopic and scotopic, mesopic photometry is also developing. Lighting standards based on the photopic function of light efficiency do not fully cover visual perception. Therefore, it is relevant to determine the characteristics related to twilight photometry, which is considered in the paper. In fact, we are talking about a new lighting paradigm - a transition from the use of a single function of light efficiency - photopic, to a multifunctional one, when one or another function of light efficiency is used, which is dictated by a specific lighting task and at the same time is regulated by the corresponding light standards. Thanks to this methodology, it is possible to increase efficiency not by literally reducing power consumption, but by taking into account the spectral characteristics of light sources. If we also take into account the emergence of a new distribution - the response curve of melatonin suppression, which has become the basis of circadian photometry, then this approach will contribute to solving the current problem of human-centric lighting. It is important to regulate light sources according to the S/P factor in order to minimize the consumption of electrical energy and increase visual efficiency. The S/P ratio is a convenient and simple way of characterizing the spectral composition of the radiation provided by various light sources. It is the influence of any spectral distribution of brightness on mesopic photometric values that can be characterized by the S/P value. The ability to calculate the S/P factor for any light source, as well as to conduct a survey of widely distributed light sources, is very important.