1、IES TM-28-14Projecting Long-Term Luminous Flux Maintenance of LED Lamps and LuminairesIES TM-28-14Projecting Long-Term Luminous Flux Maintenance ofLED Lamps and LuminairesPublication of this TechnicalMemorandum has been approvedby IES. Suggestions for revisionshould be directed to the IES.IES TM-28-
2、14Copyright 2014 by the Illuminating Engineering Society of North AmericaApproved by the IES Board of Directors, May 20, 2014, as a Transaction of the Illuminating Engineering Society of North America.All rights reserved. No part of this publication may be reproduced in any form, in any electronic r
3、etrieval system or otherwise, without prior written permission of the IES.Published by the Illuminating Engineering Society of North America, 120 Wall Street, New York, New York 10005.IES Standards and Guides are developed through committee consensus and produced by the IES Office in New York. Caref
4、ul attention is given to style and accuracy. If any errors are noted in this document, please forward them to Rita Harrold, Director of Technology, at the above address for verification and correction. The IES welcomes and urges feedback and comments. ISBN # 978-0-87995-296-9Printed in the United St
5、ates of America.DISCLAIMERIES publications are developed through the consensus standards development process approved by the American National Standards Institute. This process brings together volunteers representing varied viewpoints and interests to achieve consensus on lighting recommendations. W
6、hile the IES administers the process and establishes policies and procedures to promote fairness in the development of consensus, it makes no guaranty or warranty as to the accuracy or completeness of any information published herein. The IES disclaims liability for any injury to persons or property
7、 or other damages of any nature whatsoever, whether special, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this documentIn issuing and making this document available, the IES is not undertaking to render professional or other s
8、ervices for or on behalf of any person or entity. Nor is the IES undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining
9、the exercise of reasonable care in any given circumstances.The IES has no power, nor does it undertake, to police or enforce compliance with the contents of this document. Nor does the IES list, certify, test or inspect products, designs, or installations for compliance with this document. Any certi
10、fication or statement of compliance with the requirements of this document shall not be attributable to the IES and is solely the responsibility of the certifier or maker of the statement.IES TM-28-14Prepared by the Solid-State Lighting Subcommittee of theIES Testing Procedures CommitteeTM-28 Workin
11、g Group Emil Radkov, Technical CoordinatorSolid-State Lighting SubcommitteeEmil Radkov, ChairC. Cameron Miller, Committee LiaisonA. BakerD. EllisY. HiebertA. JacksonJ. JiaoB. Kuebler R. LeeS. LongoY. OhnoD. ParkT. PulsipherE. RichmanG. SteinbergD. SzombatfalvyR. TuttleJ. Yo n J. Adinolfi*C. Andersen
12、J. AndersonA. Baker*R. BergerR. BergmanB. Besmanoff*D. Bradley*E. BretschneiderK. Broughton*J. Burns*M. Buzard*D. Chan*G. Chan*X. Chen*J. Chesley*J. Choi*PT. Chou*A. Chowdhury*Z. Coleman*K. Cook*S. Coyne*J. Creveling*K. CurryJ. Dakin*R. Daubach*M. Dyble*D. Eckel*P. Elizondo*S. Ellersick*D. EllisC. G
13、alberth*A. Gelder*D. Grandin*M. GratherY. Guan*K. HaraguchiR. Hechfellner*K. Hemmi*S. Herman*T. Hernandez*J. Hickman*Y. Hiebert*J. HospodarskyB. Hou*S. Hua*J. HulettPC. Hung*A. JacksonJ. Jang*D. JenkinsA. Jeon*J. JiaoJ. Kahn*D. KarambelasH. Kashani*T. Kawabata*P. Keebler*S. Keeney*TY. Koo*M. Kotreba
14、iB. KueblerJ. Lee*R. LeeS. Lee*M. Lehman*J. Leland*R. Li*M. Lin*J. Linquata*MH. Lu*J. Ludyjan*R. Ma*J. MarellaM. McClear*G. McKeeJ. Melman*M. Nadal*R. Naus*D. Nava*D. Neal*A. Nishida*M. OBoyle*D. OHare*Y. Ohno*M. ORegan*D. Park*S. Patel*M. Piscitelli*M. Poplawski*B. Primerano*S. Rane*B. Rao*I. Raspu
15、tnis*E. RichmanK. Rong*R. Rykowski*E. Sahaja*M. SapcoeG. Schaefer*J. SchutzK. ScottF. Shum*S. Solimine*L. Stafford*G. Staples*G. SteinbergH. Steward*J. Swiernik*D. Szombatfalvy*T. Tomonaga*G. Trott*R. TuttleT. Uchida*V. Venkataramanan*Y. Wang*J. Welch*K. Wilcox*B. Willcock*W. Wilson*V. Wu*W. Xu*J. Y
16、o nR. Young*W. Young*G. Yu*J. Zhang* Advisory Member* Honorary MemberIES TM-28-14IES Testing Procedures CommitteeCameron Miller, ChairBecky Kuebler, Vice ChairDavid Ellis, SecretaryC. AndersenL. Ayers*A. Baker*P. Behnke*R. BergerR. Bergin*R. BergmanJC. Blacker*E. BretschneiderC. Bloomfield*K. Brough
17、ton*E. Carter*D. Chan*P-T Chou*G. Connelly*J. Dakin*R. Daubach*L. Davis*J. Demirjian*P. Elizondo*P. Franck*M. GratherY. Guan*K. Haraguchi*R. Heinisch*K. Hemmi*T. Hernandez*R. Higley*R. Horan*J. HospodarskyS. Hua*D. Husby*J.HulettP-C. HungA. JacksonD. Jenkins*J. JiaoD. Karambelas*H. Kashani*T. Kawaba
18、ta*R. Kelley*TY. Koo*M. KotrebaiJ. Lawton*J. Lee*L. Leetzow*J. Leland*K. Lerbs*R. Levin*I. Lewin*R. Li*K. Liepmann*S. LongoR. Low*MH. Lu*J. MarellaP. McCarthyG. McKeeFX. Morin*M. Nadal*D. Nava*B. Neale*Y. Ohno*J. Pan*D. Park*N. Peimanovic*E. Perkins*M. Piscitelli*G. Plank*E. RadkovD. Randolph*C. Ric
19、hards*E. Richman*K. Rong*A. Serres*M. SapcoeJ. SchutzA. SmithD. Smith*R. Speck*L. Stafford*G. SteinbergR. TuttleT. Uchida*K. Wagner*J. Walker*H. Waugh*J. Welch*K. Wilcox*B. Willcock*V. Wu*J. Yo nR. Young*J.Zhang* * Advisory Member* Honorary MemberIES TM-28-14Contents1.0 Scope .12.0 Normative Referen
20、ces 13.0 Definitions14.0 Samples and Test Data14.1 Samples .14.1.1 Sampling Selection Recommendations 14.1.2 Sample Size Recommendations14.2 Data to be Used .24.2.1 Data for Direct Extrapolation.24.2.2 Data for Combined Extrapolation .25.0 Luminous Flux Maintenance Projection 25.1 Procedures for Pro
21、jection Method 1, Direct Extrapolation of LM-84 Data .25.1.1 Normalization25.1.2 Average 25.1.3 Data Used for Curve-fit.25.1.4 Curve-fit 35.1.5 Adjustment of Results .35.1.6 Notation for Luminous Flux Maintenance Life 35.1.7 Ambient Temperature Data Interpolation45.1.7.1 Select Case Temperature Ts45
22、.1.7.2 Convert All Temperatures to Kelvins 45.1.7.3 Use the Arrhenius Equation to Calculate the Interpolated Luminous flux maintenance Life 45.1.7.4 Applicability of the Arrhenius Equation 45.1.7.5 Limit for Extrapolation.55.2 Procedures for Projection Method 2, Combined Extrapolation of LM-84 Data
23、and LM-80 Data .55.2.1 Normalization55.2.2 Average 55.2.3 Selection of LM-80 Data Set 55.2.4 Curve-fit of LM-80 Data Set .55.2.5 Calculation of the Da Value .55.2.6 Projection.65.2.7 Adjustment of Results .65.2.8 Notation for Luminous Flux Maintenance Life 76.0 Report .8Annex A LED Forward Current i
24、n the Combined Extrapolation Method8Annex B Derivation of the Formulas Used for Combined Extrapolation Method .9Annex C Example of the Combined Extrapolation Method .10Annex D Statistical Modeling .11Informative References.12IES TM-28-141IES TM-28-14Projecting Long-Term Luminous Flux Maintenance of
25、LED Lamps and LuminairesINTRODUCTIONThe objective of this Technical Memorandum is to provide guidance and recommended procedures for sampling, test intervals and duration, and a method for long term luminous flux maintenance projection for LED lamps and luminaires. The intent is to help prod-uct man
26、ufacturers and users, standard developing bodies, and other organizations to avoid any unnec-essary burdens related to excessive product testing.A balance was sought between testing time and effort, on one side, and sufficient statistical rigor, on the other. A direct and a combined method for lumi-
27、nous flux maintenance projection are proposed; the latter allows the use of luminous flux maintenance data obtained for both the lamp or luminaire being tested, and the LED sources used in it.Typically, LED sources test data are available for at least 6000 hours prior to the design of lamps or lumin
28、aires with them. This provides the starting infor-mation for the luminous flux maintenance projection according to the combined method. That method also takes into account any detectable further contri-bution from the remaining lamp or luminaire compo-nents, rather than using only LED sources test d
29、ata as a proxy. As a result, the luminous flux mainte-nance projection for the lamp or luminaire can begin as early as 3000 hours into their testing, when the protocol proposed by this document is followed.1.0 SCOPEThis document recommends the methods for pro-jecting long-term luminous flux maintena
30、nce of LED lamps and luminaires using data obtained when testing them per IES LM-84-14 Approved Method for Measuring Lumen and Color Maintenance of LED Lamps, Light Engines, and Luminaires, as well as data when testing LED sources per IES LM-80-08 Approved Method for Measuring Lumen and Color Mainte
31、nance of LED Light Sources.2.0 NORMATIVE REFERENCES2.1 IES LM-80-08 Approved Method for Measuring Lumen and Color Maintenance of LED Light Sources.2.2 IES TM-21-11 Projecting Long Term Luminous flux maintenance of LED Light Sources.2.3 IES LM-84-14 Approved Method for Measuring Luminous Flux and Col
32、or Maintenance of LED Lamps, Light Engines, and Luminaires.3.0 DEFINITIONS3.1 Device Under Test (DUT)An LED lamp or luminaire under test3.2 Sample SetThe plurality of LED lamps or luminaires being tested under a given test condition4.0 SAMPLES AND TEST DATA4.1 Samples4.1.1 Sampling Selection Recomme
33、ndations Commercial users of the information and analysis resulting from this document will, in general, assume that the data is “production representative” unless otherwise stated. “Production representative” means produced using production materials, with produc-tion processes, and production asse
34、mbly personnel, though not necessarily in a full production mode (for example, the units may be from a production pilot run). Not all testing is intended to serve the same purpose. This test method provides a standardized method that may be appropriate.Manufacturers may have a need to test in the de
35、vel-opmental stages of product design programs, or to test “production representative” versions of a product. Samples for testing shall be selected based on a docu-mented rationale that is consistent with the test intent. Whenever samples are not “production representative”, the IES TM-28-14 report
36、shall state the exceptions.4.1.2 Sampling Size RecommendationsThe required minimum number of samples of a spe-cific DUT tested at each of the specified operational and environmental conditions is 3 for the “direct” extrapolation method and 5 for the “combined” extrapolation method. The total length
37、of the projec-tion allowed depends on the number of samples used (please refer to the corresponding Adjustment of Results section in each method).2IES TM-28-144.2 Data to be UsedAll data from the sample set at a given temperature and forward current for the DUTs shall be collected according to IES L
38、M-84 for luminous flux maintenance life projection (further referred to as “LM-84 data”).An average forward current value and a case tem-perature Tsvalue (as defined in IES LM-80-08) shall be provided by the test requestor for the LED pack-ages or LED modules inside the lamps or luminaires, whenever
39、 the combined extrapolation method is used.In order to use the procedures listed in Section 5.1.7.1 and Section 5.2, the in-situ LED case temperature, Ts, in the DUT shall be obtained (see Annex A of IES LM-84-14).Data collected within a 48 hour window of each 1000 hour measurement point, e.g., from
40、 952 hours to 1048 hours, from 1952 hours to 2048 hours, etc. shall be acceptable as each 1000 hour reading and shall be used for luminous flux maintenance projection with the actual measured elapsed time value. The 48 hour window is also applicable to other intervals smaller than 1000 hours. The ac
41、tual measured elapsed time values shall be used in the projection calculation.The data collection points used in the projection cal-culation shall be equally dispersed in time (to within 48 hours). No two consecutive data collection inter-vals after the initial 1000 hours shall differ by more than 9
42、6 hours in length. For example, data may be used in the projection calculation which are collected every 1000 hours ( 48 hours), every 500 hours ( 48 hours) etc., but not every 1000 hours and occa-sionally at 500 hours, since this will give excessive statistical weight to certain data points.4.2.1 D
43、ata for Direct ExtrapolationLM-84 data shall be collected initially and at least once every 1000 hours of operating time (to within 48 hours) thereafter, for the duration of the test but over no less than 6000 hours of total operating time. Data collected at intervals greater than 1000 hours shall n
44、ot be used.4.2.2 Data for Combined ExtrapolationLM-84 data are taken for at least 3000 hours but less than 6000 hours. LM-84 data shall be collected ini-tially, at 1000 hours (to within 48 hours) of operat-ing time and at least once every 500 hours (to within 48 hours) of operating time thereafter,
45、until 6000 hours of total operating time or the end of the test, whichever comes first. Luminous flux maintenance data of LED packages or LED modules needed for combined extrapolation shall be collected according to IES LM-80-08 (further referred to as “LM-80 data”) and processed according to TM-21-
46、11.5.0 LUMINOUS FLUX MAINTENANCE PROJECTION5.1 Procedures for Projection Method 1, Direct Extrapolation of LM-84 DataThis method is recommended for all cases where at least 6000 hours of LM-84 data are available. It uses a curve-fit to the collected data to extrapolate the luminous flux maintenance
47、value to the time point where the luminous flux decreases to the minimum acceptable level (for example, 70% of initial luminous flux). That time point is the projected luminous flux maintenance life. The same curve-fit of the collected data can also be used to determine the projected luminous flux a
48、t given future time points (i.e., 25000 hours or 35000 hours).The method is applied separately for each set of DUT test data collected at each operational (e.g., drive current) and environmental (e.g., ambient tem-perature) condition, as specified in IES LM-84-14, using the following procedure. For
49、intermediate envi-ronmental conditions, the data can be interpolated as specified in Section 5.1.7.5.1.1 NormalizationNormalize all collected data to a value of 1 (100%) at 0 hours for each DUT tested.5.1.2 AverageAverage the normalized measured data of all sam-ples within the same data set defined in Section 5.1 for each test condition at each measurement point. The following sub-sections apply to the test condition under consideration.5.1.3 Data Used for Curve-fitFor data sets of test duration, D, from 6000 hours up to 10000 hours, the data used for the curve-fit shall
