Color is not a physical properly of object, but rather a human perception enabled by light. Never­theless the color of light sources is described by the industry primarily in terms of two metrics, correlated color temperature (CCT) and color rendering index (CRI), that are only indirectly related to human perception. CCT is intended to characterize the appearance of the illumination generated by source, and CRI is intended to characterize the appearance of objects illuminated be the source. There two color metrics developed nearly of half-century ago, are increasingly being challenged because new source are being developed with increasingly exotic spectral power distribution. The new color metric applicable to the color appearance of the light emitted by at light source and quantified by the CCT and D. The chromaticity is one of the critical parameters for light sources for general lighting and normally specified with chromaticity coordinates CIE (x, y) or (', '). However these two numbers do not provide the color information intuitively. For practical purposes, collated color temperature (CCT) is commonly used to provide the chromaticity information of general illumination source CCT, however, provides only one dimension of the chromaticity and there is ano­ther dimension, which is the position of chromati­city with respect to Plancian locus. For this purpose «D» or similar terms as distance from Plancian locus have been need used in some part at the industry but these had not beer officially defined is any standard. Color rendering is general term for describing the ability of a light source to provide color information to human observer when objects are illuminated by that source like CCT color rendering index (CRI), the most accepted measure of color rendering. CRI was developed, through the system of colori­metry, simply to be an indication of how «natural» or «undistorted» the light source makes the color of objects appear when illuminated by the source when used as the sole measure of color rendering for a light source, CRI simply cannot meet expectations. With the advent of SSL, these limitations have become more widely recognized. It was proposed a two-metric system combi­ning CRI, a measure of color consistency with respect to a reference source, with gamut area index (GAI), a measure of color saturation. When used to ga­ther, the two metrics appear to optimize the color appeara­nce of natural objects like fruits and vegetable enhancing their vividness with making them appear unnatural. CCT is shown in commercial instruments but D is often avai­lable. D needs to be calculated using the method of triangular solution: Create a table CCT is distance di to Plancian locus on () coordinate; Find the closest point in the table; Solve the triangle for the neighboring 2 points. Gamut area of light source is commonly calculated as the area of the polygon defined by the chromaticities in CIE 1977 (', ') color space of the light CIE TCSs. Gamut area of EES is sealed to 100 and defined as gamut area index. The gamut area of any other light source is scaled accondingle.

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The paper presents results of the thermographic and numerical analyses of the chosen design of the LED lamp radiator. The LED technology is characterized by the most dynamic development in the ligh ting market. The object of the test is the LED-1 product, which represents the unit module of the multi-module lighting system. Due to high heat fl ux on the small surface of the individual diodes, problems related to the light source cooling become to be one of the basic ones. The parameters of the test modes for the eff ects of changes in temperature are selected taking into account the physical and mechanical properties of the materials used in the manufacture of the product. Tests were conducted in a windless, dark room. Heat was discharged through convection and radiation. The tests in a dark room were conducted. Heat was discharged through convection and radiation. A thermoelectric transducer chromel-copel with dimensions of 400 μm was used to measure the temperature. The temperature was measured by passing a nominal current of 1,67 A through the module. The test results were analyzed and processed. Based on the result it was decided that the works will be continued using the advanced test stand, equipped with the system of the forced air circulation, control and data acquisition system connected with set of the temperature measurers and improved barriers, preventing the interference of the light fl ux with the thermographic measurement. The results of studies of thermal conditions and lighting parameters of the sample of the LED lamp in the process of robots are given. The ability of LED modules to resist the destructive action of heat has been determined. Inspection of potentially unreliable structural elements, strength of fasteners has been done. The luminous effi ciency of LED modules is calculated by indirect and direct, thermal and optical measurements. For the clarity of the working picture was a measured base spectral characteristic. The case temperature, with basic measurements, was 45 °C, and the ambient temperature was 24,2 °C. Analyzing the measurement results — the deviation of the light characteristics amounted to < 10 %. Bringing measurement results to model drawings in CAD SolidWorks allowed us to create a consistent computer model of the product. The model allows with sufficient accuracy to carry out all the calculations for thermal and mass-dimensional data.

Український метрологічний журнал, 2017, № 1 43 УДК 628.98 СПеКТРАЛЬНИЙ РОЗПОДІЛ ПОТУЖНОСТІ СВІТЛА ТА ПРИСМеРКОВА ФОТОМеТРІЯ Л. А. Назаренко, доктор технічних наук, професор Харківського національного університету міського господарства імені О. М. Бекетова (ХНУМГ) Т. В. Можаровська, аспірант ХНУМГ, м. Харків Д. О. Усиченко, інженер з метрології 2 категорії ДП "Харківстандартметрологія" Рис. 1. Фотопічна V(λ) та скотопічна V′ (λ) функції світлової ефективності за МКО Функція в основному охоплює спектральну чутливість фовеа (1…2º ретини) -колбочкових Т. В. Можаровська Д. О. Усиченко Л. А. Назаренко ВИМІРЮВАННЯ ОПТИЧНИХ ТА ОПТИКО-ФІЗИЧНИХ ВеЛИЧИН Український метрологічний журнал, 2017, № 1 44 Спектральний розподіл потужності світла та присмеркова фотометрія фоторецепторів. Пік спектральної чутливості знаходиться на довжині хвилі 555 нм, де за рекомендацією МКО [2] 1 Вт потужності випромінювання на 555 нм визначається як еквівалент для 683 лм [4]. Рис. 2 показує функцію фотопічної світлової ефективності, яка визначає світлову ефективність світла (лм/Вт) для різних видимих довжин хвиль. Рис. 2. Фотопічна V(λ) та скотопічна V′ (λ) функції світлової ефективності, нормалізовані при 555 нм