Review Of The Features Of Using Mini-spectroradiometers with Ccd-arrays In Applied Photometry

2021 ◽  
pp. 21-29
Author(s):  
Raisa I. Stolyarevskaya
Keyword(s):  
Spectral Characteristics ◽  
Continuous Light ◽  
Light Sources ◽  
Spectral Measurements ◽  
Integral Methods ◽  
Ccd Array ◽  
Colour Parameters ◽  
Lighting Systems ◽  
Traditional Natural ◽  
Ccd Arrays

The article is devoted to the peculiarities of solving problems of applied photometry based on the spectroradiometric approach using modern matrix spectrometers. The spectral distribution of the characteristics of the radiation source is an objective physical basis for determining its light and colour parameters. In this case, the photometric characteristics of lighting devices and lighting systems are calculated on the basis of tabulated spectral light efficiencies and ordinates of CIE colour-matching functions. The main reason for the shift in emphasis towards spectral measurements is due to revolutionary introduction into the system of internal and external lighting and signalling LED sources of light with an emission spectrum that is different from the traditional natural and artificial continuous light sources spectra. Integral methods for measuring the light and colour characteristics of semiconductor light sources require the highest quality correction of photometric channels (heads) for spectral efficiencies and colour -matching curves or taking into account a correction factor, which in turn is impossible without measuring the relative spectral characteristics of emitters and receivers. The article is a brief overview of the requirements for the CCD-array spectrometers for use in spectroradiometry and photometry.

scholarly journals Mesopic Photometry and Street Lighting

2019 ◽  
pp. 67-72
Author(s):  
L. Nazarenko ◽  
H. Kononenko ◽  
Т. Mozharovska ◽  
V. Chernets
Keyword(s):  
Traffic Safety ◽  
Spectral Characteristics ◽  
Luminous Flux ◽  
Maximum Efficiency ◽  
Light Sources ◽  
Photometric System ◽  
Street Lighting ◽  
Factors Affecting ◽  
The Road ◽  
Lighting Systems

The article reveals the question of achieving security for people on the streets at night with the help of artificial lighting. The author analyzed the factors affecting traffic safety and the possibility of creating the necessary visual conditions for this by means of street lighting. In addition, the article raised an important question regarding the characteristics of the roadway. It is noted that the modern pavement is not standardized on the lighting characteristics. Knowing the spectral characteristics of the applied light sources, these data could be applied in the development of new types of canvases that would allow achieving a new level of illumination in terms of both improving the quality and its efficiency and economy. Without this, it is impossible to talk about the maximum efficiency of the use of the luminous flux as a whole. For existing lighting systems, the brightness calculation is performed by measuring the illumination and reflectivity of the road surface. The obtained brightness values are entered into the mesopic photometric system in order to determine the parameters of the complete system, which provides equivalent visual perception of the illuminated objects and is intended to replace the existing installation. To determine the required lamp power when replacing existing luminaires, it is recommended to use a mesopic photometric system, which allows you to perform calculations taking into account the S/P ratios. In this regard, it is necessary to thoroughly review the computer programs used in the creation of the lighting project, as well as to ensure active participation in international cooperation in the formation of modern lighting standards.

Organic Light Emitting Diodes - Innovative Light Sources

2019 ◽  
pp. 101-107
Author(s):  
Sergei A. Stakharny
Keyword(s):  
Light Source ◽  
Organic Light Emitting Diodes ◽  
Organic Leds ◽  
Light Sources ◽  
High Quality ◽  
Light Emitting ◽  
Organic Light ◽  
Lighting Systems ◽  
Physical Principles ◽  
Prospects Of Application

This article is a review of the new light source – organic LEDs having prospects of application in general and special lighting systems. The article describes physical principles of operation of organic LEDs, their advantages and principal differences from conventional non-organic LEDs and other light sources. Also the article devoted to contemporary achievements and prospects of development of this field in the spheres of both general and museum lighting as well as other spheres where properties of organic LEDs as high-quality light sources may be extremely useful.

Design of Solar-Powered LED Road Lighting System

2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan
Keyword(s):  
High Pressure ◽  
Renewable Energy Sources ◽  
Junction Temperature ◽  
Mercury Vapour ◽  
Light Sources ◽  
Street Lighting ◽  
Led Light ◽  
Road Lighting ◽  
Lighting Systems ◽  
High Pressure Sodium Lamp

Turkey is rich in terms of renewable energy sources and, therefore, is now encouraging the use of sustainable clean lighting systems in road applications. High pressure sodium lamp is the most widely used type in main roads, but other types of lamps such as mercury vapour lamps or metal halide lamps can be utilized for street lighting. Since it enables energy and money saving, LED light technology has replaced high pressure sodium lamps nowadays. Once solar power system (PV) is integrated with LED lamp for street lighting, the amount of saving and local impact might be enriched. LEDs used as light sources in road lighting luminaires with rising lumen values, decreasing junction temperature, higher colour rendering efficiency, longer lifetime have become more efficient than many light sources with the latest developments. Since the structure of the luminaires in which the LED light sources are used differs from that of the conventional light sources, the optical, thermal and electrical design of the LED luminaires must be considered differently. Thus, this study concentrates upon design considerations and the operating principle of solarpowered LED road lighting luminaire in details. Also, a simple solar panel system was designed and the economical values obtained at the end of 20 years were compared when using the ongrid system and the off-grid system.

scholarly journals An Efficient Method for LED Light Sources Characterization

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1089 ◽  
Author(s):  
Sara Raggiunto ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Piergiovanni Ceregioli ◽  
Massimo Gattari ◽  
...  
Keyword(s):  
Efficient Method ◽  
Least Squares Method ◽  
Color Temperature ◽  
Experimental Setup ◽  
Light Sources ◽  
Careful Study ◽  
Source Characterization ◽  
Led Light ◽  
Lighting Systems ◽  
Led Drivers

Digital LED drivers capable of blending the spectrum of two LED fixtures with different Correlated Color Temperatures through the LEDs’ power supply control are widespread. However, the digital control of lighting systems is possible only after a careful study of the LED’s response, in terms of illuminance and Correlated Color Temperature. The proposed work takes advantage of the Tunable White technology for the realization of an efficient method for LED light source characterization. In order to evaluate how the light changes as a function of the electric power supplied by the LED drivers, an experimental setup to characterize LED light sources has been designed. Starting from the data acquired from the experimental setup, a model for dimming the LED driver and obtaining the desired values of quality of light has been developed. The proposed model is based on the least squares method and its accuracy is evaluated by comparing the obtained values of illuminance and Correlated Color Temperature with those measured by an illuminance spectrophotometer. Results achieved an error of 0.3% for Correlated Color Temperature and 1.5% for illuminance using the proposed approximation functions.

scholarly journals Towards the Optimum Light Source Spectrum

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Andrew Chalmers ◽  
Snjezana Soltic
Keyword(s):  
Light Source ◽  
Large Scale ◽  
Source Spectrum ◽  
Light Sources ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Spectral Bands ◽  
Good Energy ◽  
Lighting Systems ◽  
Colour Rendering

This paper is concerned with designing light source spectra for optimum luminous efficacy and colour rendering. We demonstrate that it is possible to design light sources that can provide both good colour rendering and high luminous efficacy by combining the outputs of a number of narrowband spectral constituents. Also, the achievable results depend on the numbers and wavelengths of the different spectral bands utilized in the mixture. Practical realization of these concepts has been demonstrated in this pilot study which combines a number of simulations with tests using real LEDs (light emitting diodes). Such sources are capable of providing highly efficient lighting systems with good energy conservation potential. Further research is underway to investigate the practicalities of our proposals in relation to large-scale light source production.

Development of a three-dimensional color rendition space for tunable solid-state light sources

2021 ◽  
Vol 2021 (29) ◽  
pp. 136-140
Author(s):  
Dorukalp Durmus
Keyword(s):  
Solid State ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Color Discrimination ◽  
Continuous Measure ◽  
Light Sources ◽  
Vast Number ◽  
Lighting Systems ◽  
Single Number

The quality of building electric lighting systems can be assessed using color rendition metrics. However, color rendition metrics are limited in quantifying tunable solid-state light sources, since tunable lighting systems can generate a vast number of different white light spectra, providing flexibility in terms of color quality and energy efficiency. Previous research suggests that color rendition is multi-dimensional in nature, and it cannot be simplified to a single number. Color shifts under a test light source in comparison to a reference illuminant, changes in color gamut, and color discrimination are important dimensions of the quality of electric light sources, which are not captured by a single-numbered metric. To address the challenges in color rendition characterization of modern solid-state light sources, the development of a multi-dimensional color rendition space is proposed. The proposed continuous measure can quantify the change in color rendition ability of tunable solid-state light devices with caveats. Future work, discretization of the continuous color rendition space, will be carried out to address the shortcomings of a continuous three-dimensional space.

Modelling the effects of inter-observer variation on colour rendition

2017 ◽  
Vol 51 (1) ◽  
pp. 37-54 ◽  
Author(s):  
MJ Murdoch ◽  
MD Fairchild
Keyword(s):  
Colour Vision ◽  
Spectral Characteristics ◽  
Observer Variation ◽  
Light Sources ◽  
Standard Observer ◽  
Natural Range ◽  
Normal Colour ◽  
Range Of Variation

The colour rendition characteristics of light sources are quantified with measures based on CIE standard observers, which are reasonable representations of population averages. However, even among people with normal colour vision, the natural range of variation in colour sensitivity means any individual may see something different than the standard observer. Modelling results quantify the effects of these inter-observer differences on colour rendition measures defined by IES TM-30-15. In general, inter-observer differences tend to be smaller for light sources with high colour fidelity values, and they are affected by spectral characteristics of different lighting technologies. The magnitude of variation in colour rendition measures, up to 5–10 units in IES TM-30-15 ( Rf, Rg), measures is compared with other sources of variability and ambiguity.

scholarly journals Researching CdZnS/ZnS (GT) Quantum Dots in Cathodoluminescent Mode

2019 ◽  
Vol 8 (9S2) ◽  
pp. 841-843
Keyword(s):  
Quantum Dots ◽  
Research And Development ◽  
Uv Light ◽  
Spectral Characteristics ◽  
Light Sources ◽  
Application Field ◽  
Medium Pressure

Application field of UV light sources is getting larger at the last decades. Among the most widespread are high and medium pressure vacuum lamps. But there currently is a trend of moving away from using mercury both in household applications and manufacturing. This creates a necessity to conduct research and development for UV sources made and operating without Hg. Cathodoluminescent UV sources are in this category. One of the possible ways to create a viable UV anode phosphor is using quantum dots with needed spectral characteristics.

System Design and Energy Management for Indoor Solar Energy Harvesting Under Consideration of Spectral Characteristics of Solar Cells

2013 ◽  
Vol 3 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Christian Viehweger ◽  
Thomas Keutel ◽  
Laura Kasper ◽  
Tim Pfeifer ◽  
Olfa Kanoun
Keyword(s):  
Solar Cells ◽  
Energy Harvesting ◽  
Energy Management ◽  
High Efficiency ◽  
Spectral Characteristics ◽  
Sensor Nodes ◽  
Light Sources ◽  
Wireless Sensor Nodes ◽  
Solar Energy Harvesting ◽  
Difficult Situations

A standardized characterization method for solar cells is only available for outdoor use. For the supply of wireless sensor nodes with energy harvesting also indoor applications are of interest. Without comparable values it is difficult to select the proper cell for defined environmental conditions. Therefore it is necessary to make an investigation on their behavior individually to be able to make a selection. The work presented here shows the characterization of solar cells according to their spectral behavior, the influence of illumination and the usage of this information about the maximum power to design an energy management. Therefore a test structure with a monochromator, different light sources, source measure units and instruments for measuring intensity and spectra has been developed. The measurements help to select the best solar cell out of a repertory for indoor energy harvesting applications. As for indoor applications also the ability to make use of weak light and a high efficiency is important, the energy management has been improved using a dual DC/DC strategy that allows it to make efficient use of solar cells within difficult situations.

scholarly journals Luminous and Melanopic Efficiency Performance of Phosphor-Converted LEDs with Tunable Spectral Characteristics

2020 ◽  
Vol 10 (18) ◽  
pp. 6198
Author(s):  
Peiyu Wu ◽  
Jiaqi Ju ◽  
Qi Yao
Keyword(s):  
Intensity Distribution ◽  
Emission Intensity ◽  
Spectral Characteristics ◽  
Spectral Composition ◽  
Light Sources ◽  
Peak Wavelength ◽  
Efficiency Performance ◽  
Circadian Effect ◽  
Color Rendering ◽  
Blue Intensity

In this work, we investigated the luminous and melanopic efficiency of the radiation (LER/MER) performances of phosphor-converted LEDs (PC LEDs) with tunable spectral characteristics, namely peak wavelength, full width at half maximum (FWHM), and emission intensity. We constructed theoretical PC LED spectra based on the characteristics extracted from the database of IES TM-30-15, analyzed the relations between LER/MER and different spectral characteristics, and proposed spectral composition strategies at various correlated color temperatures (CCTs). Results showed that both MER and LER are linear with the FWHM of phosphor within the peak wavelength range in practical use, but the change in values by tuning emission intensity varies with spectral compositions. Hence, different spectral characteristics should be considered comprehensively. We further explored the trade-off between luminous and melanopic efficiency. Lowering the FWHM of phosphor and the intensity distribution of the blue LED can obtain higher LER and low circadian effect at lower CCT. As CCT increases, considering color rendering and the increase in the blue intensity distribution, besides reducing FWHM, tuning the peak wavelength close to the peak wavelength of V(λ) helps to reduce the circadian effect. These investigations provide optimization strategies for ideal melanopic and luminous performance of PC LED light sources.

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