1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2015 SAE InternationalAll rights reserved. No part of this publi
3、cation may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/ARP5873AAEROSPACERECOMMENDED PRACTICEARP5873 REV. AIssued 2007-03Revised 2015-08Superseding A
5、RP5873LED Passenger Reading Light AssemblyRATIONALEUniform pattern shown in Figure 3 has been changed to a 267 mm radius to reduce spill lighting into adjacent seat areas. INTRODUCTIONThe purpose of this SAE Aerospace Recommended Practice (ARP) is to recommend minimum design criteria which will lead
6、 to adequate performance standards for LED passenger reading light assemblies in commercial aircraft. This document recommends design and performance criteria for light emitting diode (LED) reading lights in the passenger cabin of aircraft subject to FAR Part 25 certification. It is intended as guid
7、ance for the certifying authority. This documentis specific to passenger reading lights using LED technology. Passenger reading lights based on other technologies, such as incandescent or halogen, should be as specified in ARP378. This document includes but is not limited to commercial aircraft.1. S
8、COPEThis document presents minimum criteria for the design and installation of LED passenger reading light assemblies in commercial aircraft. The use of “shall” in this specification expresses provisions that are binding. Non-mandatory provisions use the term “should.”2. APPLICABLE DOCUMENTSThe foll
9、owing publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and
10、references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemptionhas been obtained.2.1 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel
11、: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. ARP378 Passenger Reading LightsAS8037 Minimum Performance Standard for Aircraft Position LightsTSB 003 Rules for SAE Use of SI (Metric) UnitsSAE INTERNATIONAL ARP5873A Page2of 132.2 U.S. Government PublicationsCopi
12、es of these documents are available online at http:/quicksearch.dla.mil.CFR references are available from the United States Government Printing Office, 732 North Capitol Street, NW, Washington, DC 20401, Tel: 202-512-1800, www.gpo.gov.FAR references are available from www.acquisition.gov/far.STANDAR
13、DSMIL-HDBK-217 Reliability Prediction of Electronic EquipmentOTHER PUBLICATIONSCode of Federal Regulations Title 14, Part 25Some applicable sections may include, but are not limited to the following:FAR 25.831 VentilationFAR 25.853 Compartment interiors (flammability)FAR 25.863 Flammable fluid fire
14、protectionFAR 25.869 (a)(1) Fire protection systemFAR 25.1301 Function and installationsFAR 25.1309 Equipment, systems, and installationsFAR 25.1353(a) Electrical equipment and installations (interference)FAR 25.1431 Electronic equipmentCode of Federal Regulations Title 21, Part 1040, Subpart JCFR 1
15、040.10 Radiological Health, Performance Standards for Light Emitting Products2.3 RTCA Publications Available from RTCA, Inc., 1150 18th Street, NW, Suite 910, Washington, DC 20036, Tel: 202-833-9339, www.rtca.org.RTCA DO-160 Environmental Conditions and Test Procedures for Airborne Electronics/Elect
16、rical Equipment and InstrumentsRTCA DO-178 Software Considerations in Airborne Systems And Equipment Certification2.4 IEC PublicationsAvailable from IEC Central Office, 3, rue de Varembe, P.O. Box 131, CH-1211 Geneva 20, Switzerland, Tel: +41 22 919 02 11, www.iec.ch.IEC 60825-1SAE INTERNATIONAL ARP
17、5873A Page3of 132.5 CIE PublicationsAvailable from CIE Central Bureau, Babenbergerstrasse 9/9A, 1010 Vienna, Austria, Tel: +43 1 714 31 87, www.cie.co.at.Supplement No. 2 to CIE Publication No. 15 Recommendations on Uniform Color Spaces Color Difference Equations -Psychometric Color TermsCIE 13.3-19
18、95 Method of Measuring and Specifying Colour Rendering Properties of Light SourcesCIE S 009/E:2002 Photobiological Safety of Lamps and Lamps Systems2.6 Other PublicationsAvailable from Illuminating Engineering Society, 120 Wall Street, Floor 17, New York, NY 10005-4001, Tel: 212-248-5000, www.ies.or
19、g.IESNA Lighting Handbook Journal of the Optical Society of America, Visual Sensitivities to Color Differences in Daylight, David L. MacAdam, May 1942Rensselaer Lighting Research CenterPassenger Reading Light Studyhttp:/www.lrc.rpi.edu/programs/solidstate/pdf/SAELEDreadinglightstudy4-25-05.pdf. 3. D
20、ETAILED RECOMMENDATIONS3.1 Reading Light Design3.1.1 Illuminance PatternThe reading light should provide a circular Gaussian (also known as the “normal” distribution) or circular uniform pattern of illuminance on a plane orthogonal to the beam axis located 203 mm (8 inches) above seat level. The cen
21、ter of the light pattern on the reading surface shall be located on the fore and aft centerline of the seat and the 267 mm radius of the illuminance pattern, at its closest point, shall be approximately 305 mm (12 inches) from the base of the seat back as illustrated in Figure 1. The width of the li
22、ght pattern and the illuminance within the pattern shall be in accordance with Figures 2 or 3. 3.1.1.1 Illuminance GradientThe LED passenger reading light assembly shall meet the illuminance requirements as specified in Figure 2 (normal distribution) or as specified in Figure 3 (uniform distribution
23、). 3.1.2 OpticsThe LED passenger reading light assembly optics shall be designed to meet the illuminance pattern requirements as specified in 3.1.1 when mounted at the installation height of the application. All illuminance measurements shall be made with a cosine-corrected illuminance meter that is
24、 orthogonal to the beam axis. 3.1.2.1 Optical Components QualityThe optical components (lens, reflector, etc.) should minimize defects such as scratches, chips, and air bubbles, etc., so that they do not cause noticeable non-uniformity on the illuminated surface. Resistance to environments such as U
25、V should be considered.SAE INTERNATIONAL ARP5873A Page4of 13Figure 1 - Recommended reading light installationSAE INTERNATIONAL ARP5873A Page5of 13Figure 2 - Recommended illuminance levels - Gaussian patternSAE INTERNATIONAL ARP5873A Page6of 13Figure 3 - Recommended illuminance levels - uniform patte
26、rnilluminances within the 229 mm radius shall be within 20% of each value for uniformitySAE INTERNATIONAL ARP5873A Page7of 133.1.2.1.1 LED ConsiderationsThe optical performance of a lighting assembly can be significantly affected by the LED selection and how this device affects the fundamental perfo
27、rmance and architecture of the overall lighting system. It should be understood that these aspects of LED lighting and their design from the component level on through to the system design have significant impact on the electronic circuit design and complexity; the mechanical, environmental and ther
28、mal design, choice and implementation of the optical design and a variety of performance considerations, including long term intensity, color performance, and lifetime. Some examples of these impacts are:a. Light assembly designs that utilize red-green-blue (RGB) or similar color mixing architecture
29、s experience color shift over time because the different color LEDs degrade in intensity and/or shift wavelength at various rates. Since the requisite color relies on the correct combination and ratio of light intensity from each contributing color, electronic control circuitry that utilizes color s
30、ensing feedback and independent led drive control such that each LED can be adjusted individually is prudent for many applications.b. Light assembly designs with commonly utilized LED materials in white, blue or ultra-violet (UV) LEDs may experience component and materials degradation that is normal
31、ly experienced with UV light exposure. Discoloration and embrittlement of the light source and optical components are some of the impacts.c. Light assembly designs that utilize white (photo-conversion) LEDs (such as yellow phosphor coated blue die that produce white colors) can experience a reductio
32、n in the phosphor conversion efficiency over operational time. A conversion efficiency loss can be accelerated by exposure to heat from higher temperatures. This can result in a color shifting as well as light intensity reduction.d. There is significant variability within each part number for every
33、LED device. These manufacturer variations can be minimized through careful scrutiny of the specific vendors and their products. The resulting LED assembly product designs should account for the variations in intensity, forward bias voltage, color, etc., that will be experienced lot to lot variabilit
34、y of a single manufacturer or multiple manufacturers of any specific device.e. The luminous intensity of an LED is inversely related to its ambient environment temperature. Because of this, the illuminance requirements and performance need to be considered over the expected operating temperature ran
35、ge.f. The luminous intensity of an LED is inversely related to operational usage time. End of useful life for LEDs is predominantly a result of reduced intensity and not of catastrophic failure like in incandescent or halogen reading light sources. Because of this, the illuminance requirements and p
36、erformance need to be considered over the expected life per 3.1.5.The long term performance of the LED device type(s) and the fundamental light source architecture(s) should be well understood before making a LED design selection. The light assembly design should be developed with regard for these c
37、haracteristics to ensure acceptable optical performance of each light assembly over the expected life and utilization environment. 3.1.3 White Light Color DefinitionThe LED passenger reading light assembly target color shall be SAE aviation white as specified in AS8037. Figure 4 herein illustrates t
38、he recommended color range. Aviation white, as defined herein, corresponds to a correlated color temperature (CCT) range of 2000 to 9000 K. For example, a 4300 K color temperature corresponds to u=0.220 and v=0.496 (x=0.368 and y=0.369 on the CIE 1931 chromaticity diagram). A human factors LED readi
39、ng light study suggests that a range of 3600 to 5200 K is preferred. Some factors influencing these preferences are skin tone appearance, and tasks such as computer typing, reading, and color discrimination. Aesthetically, the tolerance of the LED reading light assemblies should be within a 0.004 u,
40、 v color target radius. Within this tolerance, variations between LED reading light assemblies will not be conspicuous to most observers. LED reading light assemblies within this tolerance are classified as Group A. However, at the time of publication of this document, high flux white LEDs are not r
41、eadily available within these tolerances. Therefore, this ARP also provides for a less restrictive tolerance, classified as group B. Group B LED passenger reading light assemblies should have a color tolerance radius within 0.012 u, v about the target. This corresponds approximately to a seven step
42、MacAdam ellipse, indicating that a majority of the population will discern a color difference. It should be noted that a wide color range could result in a noticeable difference in color appearance fromlight to light. SAE INTERNATIONAL ARP5873A Page8of 133600 K5200 K0.400.420.440.460.480.500.520.540
43、.560.580.600.15 0.17 0.19 0.21 0.23 0.25 0.27 0.29 0.31 0.33 0.35uvSAE AS 8037- AviationWhiteBlack Body Curve0.012 Radius Circle1976 C.I.E. Uniform Chromaticity Scale Diagram - 2 deg. observerFigure 4 - Binning for LED reading lights3.1.3.1 Color Rendering PropertiesThe LED passenger reading light a
44、ssembly should have a minimum Color Rendering Index (CRI) of 80 in addition to having an R9 value above 80. Measurements shall be in accordance with CIE 13.3-1995.3.1.3.2 Color UniformityThe LED passenger reading light assembly shall meet the color temperature and color coordinate requirements for a
45、ny point within the illuminance pattern. There should not be visible color fringing, halo, or other noticeable change in color.3.1.4 Warm Up and StabilizationFor purposes of demonstrating compliance with this specification, all photometric and color measurements shall be made after the longer of 30
46、minutes as a minimum, and until it has reached thermal stabilization. Thermal stabilization shall be defined as the point in which light output does not change by more than 3% over a 15 minute period. 3.1.5 Lumen MaintenanceThe LED passenger reading light assembly shall be capable of meeting its ill
47、uminance over its useful life as specified by the purchasing authority. Lumen maintenance and useful lifetime, as used herein, shall be time until the LED passenger reading light assembly is no longer capable of meeting the requirements of this specification. 3.1.6 DimmingThe LED passenger reading l
48、ight assembly may be stepped or continuously dimmable. If it is dimmable, perceived brightness changes should vary linearly with the input control, and the color temperature, color coordinates, beam pattern geometry and illuminance distribution should not change appreciably over the dimming range. T
49、he LED passenger reading light shall be capable of being turned completely off.SAE INTERNATIONAL ARP5873A Page9of 133.1.7 Light TrespassThe reading light shall be designed in such a manner so that when the reading plane is orthogonal to the beam, the intensity of the light falling outside the pattern, the peripheral area beginning at a radius of 267 mm (10.5 inches) from the beam center and beyond the specified patte
