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1173
Parameters of white LEDs respecting operational conditions
Pavelka, Tomáš; Doležal, Petr; Sláma, Pavel
anglický
Paper brings knowledge from measurement on white power LEDs for general lighting applications considering operational conditions that affect quantitative and qualitative light parameters of LEDs as well as basic electrical parameters. These data are necessary for correct design of luminaire and even for basic understanding of LED behaviour in real applications, so it can be used for creation of proper model of LED parameters degradation. Measuring of LED parameter changes is based on spectroradiometry to provide information not only about luminous flux change but also about qualitative parameters changes such as chromaticity temperature and colour rendering index.
Klíčová slova:
LED; degradation; temperature; current; spectral distribution; supply voltage
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Parameters of white LEDs respecting operational conditions
Paper brings knowledge from measurement on white power LEDs for general lighting applications considering operational conditions that affect quantitative and qualitative light parameters of LEDs as ...
Home Lighting: A Challenge to Improve and Standardise
Gašparovský, Dionýz; Raditschová, Jana
anglický
Investigation presented in the paper aims to map the current situation in home lighting in order to acquire an imagination on preferences and solutions applied by end users – inhabitants, by means of available technologies and taking into account the inheritage of existing systems as well as habits of mind. Besides qualitative findings, quantitative assessment of lighting performance and estimation of energy performance is in the focus of investigation as well. Assumption of the investigation relies on the fact that what is installed in homes for lighting, selected, arranged and installed by the user, is felt by the user as illumination satisfying his needs in all aspects (aesthetic function, lighting control etc.). Questionaire is selected as the method of investigation. To achieve the needed level of reliability of data and because measurements of the illuminance are needed, the questionaire is to be completed by a professional investigator. The questionaire-based investigation is expected to provide a vast of useful information on home lighting. The paper is aimed to present the method which can be applied worldwide and to publish the results of analyses performed over data acquired on national level. Results of investigation are intended to be used for the standardization of home lighting requirements and the preparation of guidelines based on good lighting practice.
Klíčová slova:
home lighting; interior lighting; atmospheric lighting; residential buildings; lighting standardisation
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Home Lighting: A Challenge to Improve and Standardise
Investigation presented in the paper aims to map the current situation in home lighting in order to acquire an imagination on preferences and solutions applied by end users – inhabitants, by means of ...
White light in Road and Car lighting (Invited Paper)
Voelker, Stephan; Raphael, Sabine; Raynham, Peter
anglický
The article deals with the use of white light for car and road lighting. It starts with a basic investigation about brightness evaluation of different headlamps (H7, D2S, LED). The relevance of peripheral viewing for night time trafic is discussed in a second part. The last part of this article presents that differences in the light distribution are more important than differences in the lamp spectrum.
Klíčová slova:
White light; mesopic; car lighting; road lighting
Plné texty jsou dostupné v digitálním repozitáři NUŠL
White light in Road and Car lighting (Invited Paper)
The article deals with the use of white light for car and road lighting. It starts with a basic investigation about brightness evaluation of different headlamps (H7, D2S, LED). The relevance of ...
Comparison of Halogen and Xenon Headlamps in Terms of Pedestrians’ Visibility
Bradáč, Albert; Semela, Marek; Škoda, Jan; Sumec, Stanislav; Kledus, Robert; Bilík, Martin
anglický
This case study presents a comparison of visibility and recognisability (discernibility) of objects – pedestrians – on the road in rural areas at night on encounter with low beam headlights fitted with halogen lights and xenon (high-intensity discharge) lights in one and the same vehicle model. The study was inspired by the results of dynamic measuring of the reactions of vehicle drivers to the presence of pedestrians on the right side of the roadway, where the results indicated subsequent reactions of drivers driving a vehicle fitted with xenon discharge lights. The study is therefore concluded with a static comparison that confirms the factual findings.
Klíčová slova:
traffic accident; visibility; recognisability; lighting; xenon; halogen
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Comparison of Halogen and Xenon Headlamps in Terms of Pedestrians’ Visibility
This case study presents a comparison of visibility and recognisability (discernibility) of objects – pedestrians – on the road in rural areas at night on encounter with low beam headlights fitted ...
Energy Performance of Public Lighting
Gašparovský, Dionýz
anglický
After energy performance of lighting in buildings assessed in the proces of energy certification was put to life few years ago, the focus is now on energy performance of public lighting. As required by the mandate of the European Commission to the CEN to define and introduce suitable numerical indicators of the energy performance of public lighting systems, the standardisation process started in 2009. A self standing part of the standard for roadlighting, prEN13201-5 in particular, is devoted to this topic. This standard actually passed through the formal vote in CEN and release of the standard is expected in August this year. Since the begin there were several indicators like LENI, SLEEC and others under discussion, but finally a pair of compound indicators PDI and AECI won the battle. It is obvious that situation in road lighting is principially different from buildings and this fact has to be reflected in selection and definition of the indicators. Aim of this paper is to explain the different approaches and reasons of the selection of PDI and AECI as indicators for assessment of public light ing systems and to give an overview on the main parts of this draft standard with discussion on practical application of the indicators. Lighting control profiles important for calculation of the annual energy consumption incorporated in the AECI indicator are discussed as well in the paper.
Klíčová slova:
road lighting; public lighting; energy efficiency; energy performance; PDI; AECI
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Energy Performance of Public Lighting
After energy performance of lighting in buildings assessed in the proces of energy certification was put to life few years ago, the focus is now on energy performance of public lighting. As required ...
Adaptive control of public lighting
Janiga, Peter; Gašparovský, Dionýz; Barčík, Michal; Lipnický, Lukáš
anglický
Public lighting is a specific type of lighting system, which various requirements. It is a lighting system which is subject to many influences. Some impacts are changing very rapidly but a lighting system is designed for a specific case. These effects are for example traffic density, conflict situations and the impact of weather. Comprehensive regulation taking into account all the effects not currently exist but particular systems taking into account the subtasks are occuring. Paper describes possible ways to control lighting systems based on current conditions. The aim is to show the possibilities and also the technical prerequisites for the realization of such systems. Described technology is currently in its early stages and pilots projects are preparing. Aim of this paper is give information about technology and open discuss about adaptive public lighting.
Klíčová slova:
public lighting; smart grid; adaptive control
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Adaptive control of public lighting
Public lighting is a specific type of lighting system, which various requirements. It is a lighting system which is subject to many influences. Some impacts are changing very rapidly but a lighting ...
Latest Results on LED Museum Lighting: Colour Quality and Artwork Preservation (Invited Paper)
Szabó, Ferenc; Csuti, Péter
anglický
This paper describes a comprehensive study on museum lighting: one part of the study investigates the damage potential of LED museum lighting by generating composite LED spectra with the help of a mathematical algorithm, while the other part investigates the effects of LED lighting on the appearance of artworks. Spectral optimization of LED light has been carried out by using historical pigment reflectance samples instead of the test colour samples used in the CIE CRI method [CIE 1995], because the reflectance of these historic pigments is significantly different from the reflectance of today’s pigments.
Klíčová slova:
museum lighting; colour rendering; damage potential
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Latest Results on LED Museum Lighting: Colour Quality and Artwork Preservation (Invited Paper)
This paper describes a comprehensive study on museum lighting: one part of the study investigates the damage potential of LED museum lighting by generating composite LED spectra with the help of a ...
Traceability of near-field goniophotometers to the SI units
Dubnička, Roman; Rusnák, Anton; Grinaj, Lukáš; Smola, Alfonz
anglický
Goniophotometry is one of the basic photometric measurements in lighting engineering. Aim is to measure spatial characteristics of luminous parts of the luminaires and light sources represented by luminous intensity distribution curve which is needed for lighting computation at level of the preparation of lighting design. Near-field goniophotometry is still a forthcoming technology widely used in photometric laboratories all over the world. Due to compact design of these systems the laboratory space can be saved and they can be installed in a room of usual dimensions because they do not obey the inverse square law from point of view of the whole dimension of the luminaire. The principle of these goniophotometers of the luminance distribution is measurement of luminous part of the luminaires and light sources. By integration over solid angle from this fundamental photometric quantity luminous intensity in particular direction in the space represented by two angles depending on measurement planes is derived. Although theoretical principle and physical model is well-known and defined, in practical realisation of this system some problems occur. One of the problems is traceability to SI units. This fact disqualifies near-field goniophotometer in standards relating to goniophotometry. The methods to prove that near-field goniophotometer works are mostly based on computer simulations compared with practical measurements. But in the practice, appropriate calibration method with traceability to the SI units is still not available, unlike it is clearly used for farfield goniophotometers. The paper describes possibility of the calibration of near-field goniophotometers to SI units by standards which should provide fully traceable calibration to the base. Also method of validation of near-field goniophotometric systems is still opened question for future work. At the present, further works continue on the method of validation in the framework of that CIE Division 2 but this topic is out of scope of this Paper.
Klíčová slova:
Goniophotometry; Near-field goniophotometer; LIDC
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Traceability of near-field goniophotometers to the SI units
Goniophotometry is one of the basic photometric measurements in lighting engineering. Aim is to measure spatial characteristics of luminous parts of the luminaires and light sources represented by ...
Methods of validation of mirror system goniophotometers and its impact to the resulting LIDC regarding the energy performance of buildings
Grinaj, Lukáš; Dubnička, Roman; Smola, Alfonz
anglický
LIDC is an important characteristic of luminaires used in the design of new lighting systems. Mirror system goniophotometers with are based on the principle of reflection of light emitted from luminaires on the mirrors. The accuracy of the LIDC measurement is influenced by many factors. This paper deals with measurement errors which occur with this type of goniophotometer, then methods of validation of goniophotometers using a mirror system is proposed. Based on these validation methods,accuracy of the LIDC measurement on goniophotometer with mirror system can be increased. This paper also deals with the impact of the choice of LIDC measured on goniophotometer with mirror system to the quality of interior lighting systems in the framework of the energy performance of buildings. The term energy performance of buildings means the amount of energy needed to meet all the energy needs associated with a standardized usage of the building.
Klíčová slova:
LIDC; goniophotometer; mirror system
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Methods of validation of mirror system goniophotometers and its impact to the resulting LIDC regarding the energy performance of buildings
LIDC is an important characteristic of luminaires used in the design of new lighting systems. Mirror system goniophotometers with are based on the principle of reflection of light emitted from ...
Near Field Photometry
Škoda, Jan; Sumec, Stanislav; Baxant, Petr; Krbal, Michal; Pavelka, Tomáš
anglický
Paper describes deficiencies of conventional method for luminous intensity curve measuring and it brings comparison with newly used methods of near field photometry. There is also presented demonstration measurement of problematic type of luminaire with use of near field Photometry.
Klíčová slova:
luminous intensity curves; near field photometry
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Near Field Photometry
Paper describes deficiencies of conventional method for luminous intensity curve measuring and it brings comparison with newly used methods of near field photometry. There is also presented ...
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