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1 Kompendium af LEDMET publikationer 1. udgave, 26.april 2018

2 LEDMET Center for LED Metrologi er et innovationskonsortium der blev etableret i januar LED- MET har haft fokus på de problemer der opstår i forbindelse med at foretage målinger på LED produkter. Konsortiets er et samarbejde mellem Dansk Fundamental Metrologi (DFM), DTU Fotonik (Diode Lasers & LED Systems), DELTA a part of Force Technology og Dansk Center for Lys (DCL). Samarbejdende danske virksomheder er Louis Poulsen Lighting, Senmatic, ChromaViso, Viso Systems, LightCare, Brother, Brother & Sons, North Invent, LEDiBond, LEDProof, Danelec Marine, Martek Marine, Morfoso, Ingemann Components, HAI Horsens, Eclat Digital, and Efsen Engineering. Mere information kan findes på Ansvarsfraskrivelse: Forfatterne og LEDMET Center for LED Metrologi har gjort deres yderste for at sikre nøjagtigheden og pålideligheden af dette dokument. Der gives ingen garanti for nøjagtigheden af data heri eller accepterer nogen form for ansvar for enhver handling eller beslutning, der træffes på baggrund af indholdet af dette dokument. Side 2

3 Indhold Indledning... 4 Beskrivelse af arbejdspakker Fundamental metrologisk forskning og udvikling... 6 Test of traceability between DFM s cryogenic radiometer and spectral irradiance scale Etablering af fuld spektral irradians skala med min. 7 bølgelængder... 8 Comparison of stray light in spectrometer systems using a low cost monochromatic light source... 9 Konstruktion af styrbar variabel LED baseret lyskilde til optimering og kalibrering Håndholdte spektrometre er smarte, men usikre Hvordan tjener man penge på måleusikkerhed? Luminous flux and colour maintenance investigation of integrated LED lamps Studier af fysiologisk respons med fokus på cirkadisk rytme Udvikling af metoder til farvekalibrering af LED baserede produkter Laser driven white light source for BRDF measurement New Light Source Setup for Angle Resolved Light Absorption measurement of PV samples Assessment of filament led bulbs with respect to temporal light artefacts Photometric and Colorimetric Comparison of HDR and Spectrally Resolved Rendering Images Dynamiske lyskilder Goniofotometri og goniospektrometri Auxiliary correction in goniophotometry, simulation and measurement A comparison of goniophotometric measurement facilities Analysis of compact and portable goniospectrometer system for test of LED lamps LEDMET Laboratory intercomparison Nyt farvegengivelses indeks der er måske lys forude Forskellige resultater ved lysberegninger i Dialux og Dialux EVO Giver LED-pærer det samme lys i Kina. Danmark og USA? Goniometric characterization of LED based greenhouse lighting Light source characterization and air movement under CIE S UV LED er Test af udvidelse af sporbarhed for optisk effekt til UV området ved hjælp af termisk detektor ved 2 bølgelængder med en usikkerhed bedre end 1% Udvikling af metode til karakterisering og kalibrering af filterbaserede UV detektorer med ukendt transmission Side 3

4 Indledning Forskning & udvikling inden for LED teknologi resulterer i LED-komponenter med stadig stigende lysmængde og effektivitet. Som konsekvens af dette er LED i dag at finde i signal- og skiltebelysning, i langt de fleste displays fra mobiltelefoner til TV-skærme, men også i stigende grad i generel belysning. Nye LED belysningsprodukter har allerede i dag med hensyn til energieffektivitet og lyskvalitet ertattet gløde-, halogen- og sparepærer, og fremtidsudsigterne er, at LED forbliver den mest energieffektive kunstige lyskilde. Også i det ultraviolette område er LED-teknologien i rivende udvikling, og UV LED kan forventes at erstatte eksisterende UV lyskilder i den nære fremtid og føre til nye anvendelser. Center for LED Metrologi (LEDMET) har haft til formål at drive forskning og innovation inden for optisk metrologi rettet mod LED-baserede systemer/lyskilder med fokus på radiometri i UV-området og det synlige spektralområde samt fotometri og kolorimetri. Forskningen og innovationen omfattede nye metoder til måling og korrektion af instrumenter, der sikrer bedst mulige måleresultater, samt helt nye parametre, som et analyseret gennem projektets milepæle. Forskningen har også haft til formål at sikre kvaliteten af sådanne målinger igennem sporbarhed til en national primærnormal for optisk effekt og analyse af usikkerhed i målingerne. Dette kompendie indeholder en oversigt af de rapporter og artikler, der er udgivet af LEDMET gennem projektets 4-årige forløb. Det er ikke en fuldstændig komplet samling men udgør størstedelen af de udgivne rapporter og artikler. Kompendiet er inddelt i 4 hovedkapitler, iht. projektets forskningsmæssige arbejdspakker. I hvert kapitel findes abstracts af rapporter eller hele artikler, henvisning til udgivelsessted og kontaktoplysninger på forfatter og/eller udgiver. Beskrivelse af arbejdspakker Arbejdspakke 1 - Fundamental metrologisk forskning og udvikling Metrologiarbejdspakken har forskningsmæssigt koncentreret sig om den grundlæggende radiometriske måling af optisk effekt med forskellige detektorer og spektrometre og relatere disse til den nationale primærnormal for optisk effekt. For alle de typer målinger, der indgår i LEDMET som farvekoordinater, vinkelfordelinger eller effekt af lys i både UV-området og det synlige område, er den nødvendige forudsætning en nøjagtig kalibrering af det udstyr, der anvendes. Den nødvendige basis for disse kalibreringer vil blive etableret med fokus på to hovedområder: 1) Etablering af en spektral irradiansnormal i det synlige område, som er sporbar til den nationale primærnormal for optisk effekt; 2) formidling af bestpractice guidelines for nøjagtig måling af synligt lys Arbejdspakke 2: Udvikling af metoder til farvekalibrering af LED baserede produkter Kolorimetri omhandler farvebestemmelse af såvel materialer - baseret på reflektans eller transmission eller farven på lysende produkter som f.eks. LED displays og -skilte. Arbejdspakken omfattede forskning og udvikling af avancerede metoder til farvemåling på begge produktgrupper. En begrænsning ved de eksisterede teknologier til farvekalibrering af displays og skilte er at den spektrale følsomhed ikke levede op til normerne for farvefølsomhed over hele billedfeltet. For at opnå den nødvendige præcision er der forsket i og udviklet på korrektionsmetoder der sikrer sporbarhed for luminans og kromaticitet for hver pixel i billedfeltet samt adaptive reguleringsmetoder for opnåelse af luminans og kromacitet for alle kalibreringsfarver. Afgørende for avancerede lystekniske simuleringsværtøjers nøjagtighed er validiteten af de materialedata der anvendes. DTU Fotoniks goniometer system med farvekamera er blevet udbygget til at kunne Side 4

5 måle de reflektans -og spredningsdata der skal anvendes, for at opnå den nødvendige præcision af simuleringsværktøjerne. Her er det sikret at DTU s karakteriseringssystem generer sporbare spredningsdata og at demonstrere disse datas anvendelighed i armaturkonstruktion. Dette er realiseret gennem udvikling af analyse-metoder for data (luminans samt kromacitet) sammenholdt med laboratoriemålinger i specifikke geometrier samt ved kontrol af den totale spredning ved hjælp af en integrerende kugle. Arbejdspakke 3: Goniofotometri og goniospektrometri LED baserede lyskilder/armaturer giver en række problemer med goniofotometermålinger, og det er disse, som arbejdspakke 3 har arbejdet med. Et goniofotometer benyttes til måling af intensitetsfordelingen af lyset fra en lyskilde eller et armatur som funktion af udstrålingsvinkel. Det er essentiel information for produkter og bruges, når man skal modellere/dimensionere belysningsløsninger, men det kræver store og dyre faciliteter. En række danske virksomheder har investeret i denne type udstyr, og de er med i dette innovationskonsortium. LEDMET konsortiet har med dets deltageres faciliteter haft en enestående mulighed for at lave omfattende sammenligninger af målinger på forskellige typer af goniometre og derigennem verificere nye korrektionsmetoder og målemetoder. Arbejdspakke 4: UV LED er Karakteriseringen og anvendelsen af UV-lys stiller meget større krav til bestemmelse af bølgelængdeog intensitetsafhængighed af de eksponerede emner end det er tilfælde t for synligt lys. Dette skyldes, at en lille ændring i lysets sammensætning kan medføre dramatiske ændringer i effekten af en eksponering. Dette stiller store krav til det anvendte udstyr i form af båndbredde, følsomhed overfor baggrundsbelysning og dynamisk måleområde. Ovennævnte udfordringer blev adresseret i denne arbejdspakke. Hvor der er arbejdet med at udvikle metoder til nøjagtig og sporbar måling af LED-baseret UV-lys, der anvendes i laboratorier, i produktionsfaciliteter, til medicinsk behandling samt i systemer, der forventes at vinde indpas i fremtidige anvendelser. Der vil blive etableret en platform baseret på en integrerende kugle, der gør det muligt at karakterisere egenskaberne ved UV-LED er, der kan bidrage til at opnå en bedre forståelse af deres ydeevne, til bestemmelse af UV-lysets påvirkning af materialer med fokus både på den nedbrydning, UV-lys kan forårsage og de muligheder UV-lys giver for eksempelvis medicinsk behandling. Side 5

6 1 Fundamental metrologisk forskning og udvikling Samling af resumeer fra LEDMET Arbejdspakke 1 Side 6

7 PMT current [A] Test of traceability between DFM s cryogenic radiometer and spectral irradiance scale. [LEDMET report: Sporbarhed ved tre synlige bølgelængder] 2014 Brusch, Anders; Petersen Jan C. DFM, DTU Science Park, Hørsholm, DENMARK ab@dfm.dk Abstract The report details the first comparison between the cryogenic radiometer at DFM and the spectral irradiance scale of a reference lamp. The cryogenic radiometer is the primary standard for optical power with an uncertainty below 0,04. In contrast, the lamps that are used to realize the spectral irradiance scale have an uncertainty of about 1%. By comparing the lamp directly to the cryogenic radiometer, we can reduce the uncertainty of the former. The report details the setup and measurement procedure used to perform the comparison. An important part of the measurement is the accurate characteri zation of the sensitivity of the spectroradiometer used to perform the comparisons. With this characterization, the lamp and lasers can be compared. The report details the data treatment and final results that show a deviation below 0,5 % between. 1,E-06 1,E-07 Spektroradiometer respons 1,E-08 1,E-09 1,E-10 1,E Wavelength [nm] Spectroradiometer response with laser at 568 nm Side 7

8 Etablering af fuld spektral irradians skala med min. 7 bølgelængder [LEDMET report: Traceabilty between the optical power and spectral irradiance scale (draft under revision)] 2017 Brusch, Anders; Petersen Jan C. DFM, DTU Science Park, Hørsholm, DENMARK ab@dfm.dk Abstract The report discusses the improvements and expansions of the original setup for testing traceability. Among these expansions are a thermal detector head with a response that is independent of wavelength. This detector makes it possible to extend the measurement range beyond the limited calibration wavelengths of the trap detectors that serve as the link to the cryogenic radiometer. This also allows extension into the UV range, where we are not directly traceable to the cryogenic radiometer. In the current setup, we have 7+ lasers in the visible spectral region. These can in turn be coupled into the stabilization and measurement part of the setup, using optical fibers and flip-mirrors. The report details the measurement procedure that first transfers traceability between the trap detectors and the thermal detector. This extends the calibration points of the trap detector to cover all the available lasers. In the next measurement series, the lamp is compared to the lasers using the procedures established in the original test. The first series of results showed good agreement, but with a consistent offset of approximately 2%. We are attempting to address this offset in a new measurement series that is about to be finalized. Side 8

9 Comparison of stray light in spectrometer systems using a low cost monochromatic light source [Proceedings of CIE 2014: Lighting Quality and Energy Efficiency. International commision on illumination, p ] 2014 Thorseth, Anders; Lindén, Johannes; Dam-Hansen, Carsten. DTU Fotonik, Technical University of Denmark, Roskilde, DENMARK andt@fotonik.dtu.dk Abstract We present an experimental setup that is under development for automated stray light characterization of spectrometers. The setup uses a tuneable monochromator which enables this characterization on relatively cost low equipment. We present the measured line spread functions for two spectrometers, one low-end and one mid-range. Keywords: Spectroradiometry, Line spread functions, Stray light correction Side 9

10 Konstruktion af styrbar variabel LED baseret lyskilde til optimering og kalibrering [LEDMET instrument report: Multicolor LED source] 2015 Brusch, Anders; Petersen Jan C. DFM, DTU Science Park, Hørsholm, DENMARK Abstract A report has been written to document the multi LED setup. This setup contains 11 different color LED s on a single board. The LED s range from 425 nm to 740 nm, covering most of the visible regime. The LED s are coupled into a large integrating sphere. The LED s can be individually controlled using a driver unit based on LUXDRIVE Buckblock LED drivers. The setup has been used for investigation of luxmeter spectral sensitivity. This is needed to calculate the correction to luxmeters that are used to measure LED light sources. LED sources have a very different spectral distribution than the tungsten/halogen lamps typically used for calibration of lux meters. This difference can lead to significant errors if the lux meter response deviates from the luminosity function. This is particularly if there is a big error in the blue spectral region, where most white light LED s have a prominent peak. Software has been created that can calculate a correction to the tested lux meter in the form of a polynomial. Side 10

11 Håndholdte spektrometre er smarte, men usikre LYS 02, 2017, Anders Thorseth, DTU Fotonik, Side 11

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13 Hvordan tjener man penge på måleusikkerhed? LYS 03, 2015, Anders Thorseth, DTU Fotonik, Side 13

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15 Luminous flux and colour maintenance investigation of integrated LED lamps [In Proceedings of CIE 2014: Lighting quality and energy efficiency. CIE - International Commission on Illumination. pp ] 2014 Corell, Dennis Dan; Thorseth, Anders; Dam-Hansen, Carsten DTU Fotonik, Technical University of Denmark, Roskilde, DENMARK andt@fotonik.dtu.dk Abstract This article will present an investigation of the luminous flux and colour maintenance of white LED based retrofit lamps. The study includes 23 different types of integrated LED lamps, covering 18 directional and 5 non-directional. Luminous flux and colour data for operation up to h has been measured, and will be presented. Data for the first 6000 h of operation is used for studying extrapolation method and results are compared with experimental data for operation over h. It has been further examined when catastrophic failures occurred. Keywords: LED, LEDi, Lumen maintenance, Colour maintenance, Lifetime Side 15

16 Studier af fysiologisk respons med fokus på cirkadisk rytme. [LEDMET report: Circadian light optimization software.] 2017 Brusch, Anders; Petersen Jan C. DFM, DTU Science Park, Hørsholm, DENMARK The report describes software developed to optimize circadian response and other light quality measures for a set of LED s. The software can simultaneously optimize the color -rendering index (CRI) and circadian response for a fixed color temperature. The circadian response can be optimized with respect to any given model function for the circadian response. The software performs a stochastic minimization of a function that contains the three light quality parameters (CRI, Color temperature and circadian weighted spectrum). Depending on exact form of the minimization function, the different parameters can be more or less relaxed. In typical simulations, the constraints are set so the CRI will always be above a limiting value, and the color coordinate in CIE 1931 color space is within 0,003 of the point on the Planc kian locus corresponding to the set color temperature. The software provides the relative power levels of the LED s used. Cirkadisk påvirkning for multi LED kilde som funktion af farvetemperatur Side 16

17 2 Udvikling af metoder til farvekalibrering af LED baserede produkter Samling af resumeer fra LEDMET Arbejdspakke 2 Side 17

18 Laser driven white light source for BRDF measurement [In proceedings of the Conference on "Smarter Lighting for Better Life" at the CIE Midterm Meeting CIE - International Commission on Illumination, p ] 2017 Amdemeskel, Mekbib Wubishet; Thorseth, Anders; Dam-Hansen, Carsten. DTU Fotonik, Technical University of Denmark, Roskilde, DENMARK mekwub@fotonik.dtu.dk Abstract This In this paper, we will present a setup with laser driven light source (LDLS) for measuring a 2D bidirectional reflectance distribution function (BRDF). We have carried out measurements to acquire the BRDF of different samples based on our setup: which consists of a new laser driven broadb and light source (UV-VIS-NIR), spectroradiometer and sample holder stepper motor in a dark UV-protected environment. Here, we introduced a special kind of light source which has a bright, stable, broad spectral range and well collimated light output to give a very good angular resolution. The experimental results show how stable and reliable is our light source in terms of spectral power distribution, and in BRDF measurement. Furthermore we have shown that we are able to get a well collimated beam and highe r power output using set of off-axis parabolic mirrors. Keywords: LED, LEDi, Lumen maintenance, Colour maintenance, Lifetime Side 18

19 New Light Source Setup for Angle Resolved Light Absorption measurement of PV samples [presented at 5th internation workshop on LED and Solar Applications, Kgs. Lyngby, Denmark.] 2017 Amdemeskel, Mekbib Wubishet; Poulsen, Peter Behrensdorff; Thorsteinsson, Sune; Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Thorseth, Anders; Dam-Hansen, Carsten DTU Fotonik, Technical University of Denmark, Roskilde, DENMARK Abstract Here, we introduce measurements of angle resolved light absorption by PV cells, using broadband laser driven white light source with a bright, stable, broad spectral range and well collimated light. Keywords: absorption; collimated; reproducibility; laser Side 19

20 Assessment of filament led bulbs with respect to temporal light artefacts [In Proceedings of the Conference on "Smarter Lighting for Better Life" at the CIE Midterm Meeting 2017 (pp ). CIE - International Commission on Illumination. DOI: /x PP38 ] 2017 Lindén, Johannes; Thorseth, Anders; Corell, Dennis Dan; Dam-Hansen, Carsten. DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Roskilde, DENMARK johli@fotonik.dtu.dk Abstract Temporal light artefacts, abbreviated TLAs (including flicker, stroboscopic effect and phantom arrays), i.e. undesired time modulation in luminance from a light source, has shown to be a threat to wider SSL adoption especially related to dimming functions and low-quality LED products. This is due to the effects that both noticeable and unperceivable TLAs have on human perception and wellbeing. In the present work a number of filament LED bulbs, currently available on the market, are assessed primarily with respect to TLAs, but also with respect to photometric, colorimetric and efficiency properties. The inve s- tigation shows that only one of the 10 investigated lamps can be considered flicker free. The rest of the lamps the TLAs are of such a magnitude that none of them fulfil the suggested recommendations currently available. Keywords: Temporal Light Artefacts, TLA, Flicker, Filament LEDs, Dimming, Photometry, Colorimetry, Colour Rendering Side 20

21 Photometric and Colorimetric Comparison of HDR and Spectrally Resolved Rendering Images [In Proceedings of the 4th CIE Expert Symposium on Colour and Visual Appearance p ] 2017 Amdemeskel, Mekbib Wubishet; Soreze, Thierry Silvio Claude; Thorseth, Anders; Corell, Dennis Dan; Dam-Hansen, Carsten DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Roskilde, DENMARK Abstract In this paper, we will demonstrate a comparison between measured colorimetric images, and simulated images from a physics based rendering engine. The colorimetric images are high dynamic range (HDR) and taken with a luminance and colour camera mounted on a goniometer. For the comparison, we have used a scene similar to the cornel box (CUPCG, 1998) but with a spectrally controllable LED light source, neutral grey walls and a colour checker board for colorimetric assessments. The luminance value and colour information of the HDR camera and rendering images are used for the comparison. The spectral irradiances of the light source were measured for two lighting scenarios: low and high correlated colour temperature (CCT) white lighting conditions for the modelling of the light source. Based on these measurements, we have conducted spectrally resolved renderings with a spectral renderer, Ocean. The colour differences between the camera and rendered images were calculated with the most recent CIE metric, CIEDE2000 (CIE, 2012). Our simulations have demonstrated interesting results, which confirm the accuracy of the Ocean engine. In the future, we want to consider non -Lambertian surfaces. Keywords: Luminance meter, Colorimeter, Spectrally resolved rendering, Correlated colour temperature, Lambertian Side 21

22 Dynamiske lyskilder LYS 1, 2018, p , Carsten Dam-Hansen, Dennis Corell og Anders Thorseth, DTU Fotonik, Risø campus, Frederiksborgvej 399, 4000 Roskilde, Side 22

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24 3 Goniofotometri og goniospektrometri Samling af resumeer fra LEDMET Arbejdspakke 3 Side 24

25 Auxiliary correction in goniophotometry, simulation and measurement [In proceedings of CIE Expert Symposium on the CIE S 025 LED Lamps, LED Luminaires and LED modules Test Standard, 2015, Braunschweig, Germany] 2015 Thorseth, A. 1, Lindén J. 1, Corell D. D. 1, Dam-Hansen C. 1 1 DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark andt@fotonik.dtu.dk Abstract Goniophotometric measurements are susceptible to temporal changes in the light output of the device under test (DUT), due to the extended duration of the measurement. This paper outlines our work with two different approaches to auxiliary correction of goniophotometric measurements. We have carried out a goniophotometric auxiliary correction using temperature measurements, which reduces the error on an unstabilized DUT by a factor of 20. We further seek to quantify the feasibility of using a direction with high signal and low gradient for monitoring the stability of the DUT, eliminating the error associated with low correction signals or the angular uncertainty combined with a steep gradient. Our data indicate that for significant part of our goniophotometric test measurements a selected monitoring direction could be beneficial. Keywords: Goniophotometry, temperature correction, uncertainty analysis Side 25

26 A comparison of goniophotometric measurement facilities [Proceedings of CIE 2016 Lighting Quality and Energy Efficiency. CIE - International Commission on Illumination, p ] 2016 Thorseth, A. 1, Lindén J. 1, D. 1, Dam-Hansen C. 1 1 DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark andt@fotonik.dtu.dk Abstract In this paper, we present the preliminary results of a comparison between widely different goniophotometric and goniospectroradiometric measurement facilities. The objective of the comparison is to increase consistency and clarify the capabilities among Danish test laboratories. The study will seek to find the degree of equivalence between the various facilities and methods. The collected data is compared by using a three-way variation of principal component analysis, which is well suited for modelling large sets of correlated data. This method drastically decreases the number of numerical values needed to represent the data. The model shows good agreement with data, while also highlighting the differences between the measurements. We conclude that the method could be useful for comparing large sets of goniophotometric data. Keywords: e.g. Goniophotometry, Intensity distributions, principal component analysis, Side 26

27 Analysis of compact and portable goniospectrometer system for test of LED lamps [Proceedings of 28th CIE Session PO ] 2015 Dam-Hansen C. 1, Amdemeskel M. 1, Thorseth A. 1, Corell D. 1, Lindén L. 1, Markussen T. 2, and Krause C. 3 1 DTU Fotonik, Technical University of Denmark, Roskilde, Denmark 2 Sekretariat for Ecodesign og Energimærkning af Produkter, Odense, Denmark 3 Viso Systems Aps, Aarhus, Denmark cadh@fotonik.dtu.dk Abstract An experimental investigation of a compact and portable goniospectrometer system is described. Measurements are performed in two very different conditions, in a normal office environment and in a photometry laboratory under standard environmental conditions and both are compared to reference measurements in a near-field goniophotometer. A collection of six different types of directional and non-directional integrated LED lamps with three samples of each were used as test devices. It is shown that the main uncertainty comes from the inadequate thermal stabilisation of the LED lamps. With pre - heating relative differences for total luminous flux of ±2,5% were obtained. Reliable photometric data can be obtained for use in market monitoring to identify probable non-compliance LED lamps and hence as an improved method for selecting LED lamps for accredited verification testing. Keywords: LED lamps, Goniophotometry, Goniospectrometry, Solid State Lighting Side 27

28 LEDMET Laboratory intercomparison [LEDMET report: Anders Thorseth and Carsten Dam-Hansen DTU Fotonik, Technical University of Denmark, Roskilde, Denmark Abstract This report describes the goniophotometric and goniospectroradiometric laboratory intercomparison under work package 3 within the LEDMET Center for LED Metrology. The participating laboratories and their facilities, devices under test and procedures are presented. Results of measured electrical, photometric and colorimetric parameters for a narrow beam LED lamp are analysed for a number of measurements carried out by the four participating laboratories. The measurement results presented have been anonymised. These show an equivalence of the measured parameters within a limited variation, with the exception of single outliers that may be caused by systematic errors. Keywords: LED lamps, metrology, goniophotometry, laboratory intercomparison Side 28

29 Nyt farvegengivelses indeks der er måske lys forude LYS 04, 2015, Anne Bay, Dansk Center for Lys Side 29

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31 Forskellige resultater ved lysberegninger i Dialux og Dialux EVO LYS 04, 2016, Henrik Aagaard Pedersen, Louis Poulsen Side 31

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33 Giver LED-pærer det samme lys i Kina. Danmark og USA? LYS 03, 2015, Anders Thorseth, DTU Fotonik, andt@fotonik.dtu.dk Side 33

34 Goniometric characterization of LED based greenhouse lighting [In proceedings of 28th CIE Session OP10 131] 2015 Thorseth A. 1, Corell D. 1, Lindén L. 1, Dam-Hansen C. 1 1 DTU Fotonik, Technical University of Denmark, Roskilde, Denmark andt@fotonik.dtu.dk Abstract An experimental investigation of a compact and portable goniospectrometer system is described. Measurements are performed in two very different conditions, in a normal office environment and in a photometry laboratory under standard environmental conditions and both are compared to reference measurements in a near-field goniophotometer. A collection of six different types of directional and non-directional integrated LED lamps with three samples of each were used as test devices. It is shown that the main uncertainty comes from the inadequate thermal stabilisation of the LED lamps. With pre - heating relative differences for total luminous flux of ±2,5% were obtained. Reliable photometric dat a can be obtained for use in market monitoring to identify probable non-compliance LED lamps and hence as an improved method for selecting LED lamps for accredited verification testing. Keywords: LED lamps, Goniophotometry, Goniospectrometry, Solid State Lighting Side 34

35 Light source characterization and air movement under CIE S 025 [In proceedings of the Conference on "Smarter Lighting for Better Life" at the CIE Midterm 2017] 2017 Thorseth A. 1, Bergen, A. S. J. 2 1 DTU Fotonik, Technical University of Denmark, Roskilde, Denmark 2 Photometric Solutions International Pty Ltd, Australia andt@fotonik.dtu.dk Abstract In 2015, the International Commission on Illumination (CIE) published the standard CIE S025/E:2015 Test Method for LED Lamps, LED Luminaires and LED Modules. This document contains a number of standard test conditions, including laboratory room preparation, environmental and electrical provisions as well as requirements for the performance of testing and measurement equipment. One of the environmental considerations is a restriction of the airflow incident on the device under test. The sensitivity of LED source based devices to airflow is important for estimating the uncertainty originating from airflow. We find that for most of the tested devices the sensitivity is on the order of 5 %/(m/s), which is consistent with CIE S 025. However, we also found an example of a device with a larger sensitivity. Additionally we study general airflow measurements and influence of turbulence. Keywords: Photometry, Testing, Airflow, Solid state lighting Side 35

36 4 UV LED er Samling af resumeer fra LEDMET Arbejdspakke 4 Side 36

37 Test af udvidelse af sporbarhed for optisk effekt til UV området ved hjælp af termisk detektor ved 2 bølgelængder med en usikkerhed bedre end 1%. [LEDMET report: UV traceability using LED (draft under revision)] 2017 Brusch, Anders; Petersen Jan C. DFM, DTU Science Park, Hørsholm, DENMARK ab@dfm.dk The report describes a comparison between the cryogenic radiometer and lamps in the UV spectral region. As opposed to the similar comparisons in the visible spectral region, we use UV LED s as light sources. This is motivated by the difficulties that were encountered in using a frequency doubled light source at 266 nm. The LED s that are used are centered at 278 nm and 315 nm. Both LED s can deliver 100 mw in steady state operation from a single ~1x1 mm die. This is enough to create a well -collimated beam of light with a power above 1 mw, that can be used in the established setup in the same way as we use a laser. For this test we have not used the trap detector as reference, but have relied on the thermal detector head and the calibration of its sensitivity established during previous measurements. This is to avoid the risk of damage to the trap detectors. When working in the UVC regime, we have experience significant Diffusil measurement head for high power UV Side 37

38 Udvikling af metode til karakterisering og kalibrering af filterbaserede UV detektorer med ukendt transmission. [LEDMET report: Characterization of UVA sensor using LED s (draft under revision)] 2017 Brusch, Anders; Petersen Jan C. DFM, DTU Science Park, Hørsholm, DENMARK ab@dfm.dk The report describes characterization of a filter-based UVA sensor (Solarmeter, model 4.2) using LED s. The measurement is performed using a UVA / blue light LED board that covers the spectral range from 365 nm to 460 nm. To extend the measurement range we use two individually mounted LED s at 340, 325 and 315 nm. Measurements are performed with the same setup that is used in the visible range. In contrast to determining a correction to the luminosity function, we measure the sensitivity at the available wavelengths and give the results without trying to determine an analytical sensitivity function. Close-up of UVA + blue light LED print Side 38

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