DOCSLIB.ORG

Degradation in PV Encapsulation Transmittance: an Interlaboratory Study Towards a Climate-Specific Test Preprint David C

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Degradation in PV Encapsulation Transmittance: an Interlaboratory Study Towards a Climate-Specific Test Preprint David C Degradation in PV Encapsulation Transmittance: An Interlaboratory Study Towards a Climate-Specific Test Preprint David C. Miller, Eleonora Annigoni, Amal Ballion, Jayesh G. Bokria, Laura S. Bruckman, David M. Burns, Xinxin Chen, Lamont Elliott, Jiangtao Feng, Roger H. French, Sean Fowler, Xiaohong Gu, Peter L. Hacke, Christian C. Honeker, Michael D. Kempe, Hussam Khonkar, Michael Köhl, Laure-Emmanuelle Perret-Aebi, Nancy H. Phillips, Kurt P. Scott, Fanny Sculati-Meillaud, Tsuyoshi Shioda, Shigeo Suga, Shin Watanabe, and John H. Wohlgemuth See inside for authors’ affiliations Presented at the 42nd IEEE Photovoltaic Specialists Conference New Orleans, Louisiana June 14–19, 2015 NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. Conference Paper NREL/CP-5J00-63508 August 2015 Contract No. DE-AC36-08GO28308 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (Alliance), a contractor of the US Government under Contract No. DE-AC36-08GO28308. Accordingly, the US Government and Alliance retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof. This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. Available electronically at SciTech Connect http:/www.osti.gov/scitech Available for a processing fee to U.S. Department of Energy and its contractors, in paper, from: U.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 OSTI http://www.osti.gov Phone: 865.576.8401 Fax: 865.576.5728 Email: [email protected] Available for sale to the public, in paper, from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 NTIS http://www.ntis.gov Phone: 800.553.6847 or 703.605.6000 Fax: 703.605.6900 Email: [email protected] Cover Photos by Dennis Schroeder: (left to right) NREL 26173, NREL 18302, NREL 19758, NREL 29642, NREL 19795. NREL prints on paper that contains recycled content. Degradation in PV Encapsulation Transmittance: An Interlaboratory Study Towards a Climate-Specific Test David C. Miller1, Eleonora Annigoni2, Amal Ballion3, Jayesh G. Bokria4, Laura S. Bruckman5, David M. Burns6, Xinxin Chen7, Lamont Elliott8, JiangtaoFeng7, Roger H. French5, Sean Fowler9, Xiaohong Gu10, Peter L. Hacke1, Christian C. Honeker11, Michael D. Kempe1, Hussam Khonkar12, Michael Köhl3, Laure-Emmanuelle Perret-Aebi13, Nancy H. Phillips6, Kurt P. Scott8, Fanny Sculati- Meillaud2, Tsuyoshi Shioda14, Shigeo Suga15, Shin Watanabe15, and John H. Wohlgemuth1 1National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway, Golden, CO 80401, USA 2École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71B, Ch-2002 Neuchâtel, Switzerland 3Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstrasse 2, 79110 Freiburg, Germany 4Specialized Technology Resources, Inc. (STR), 10 Water Street, Enfield, CT, USA 06082 5Case Western Reserve University (CWRU), White 538, 10900 Euclid Avenue, Cleveland, OH 44106, USA 6The 3M Company, 3M Center, Building 235-67-15, St. Paul, MN, 55144, USA 7China National Electric Apparatus Research Institute Co., Ltd. (CEI), Guangzhou, 510663, P. R. China 8Atlas Material Testing Technology L.L.C., 1500 Bishop Court, Mount Prospect, IL 60056, USA, 9Q-Lab Corporation, 800 Canterbury Road, Cleveland, OH 44145 USA 10National Institute of Standards and Technology (NIST), 100 Bureau Dr., Gaithersburg, MD 20899-8615, USA 11Fraunhofer Center for Sustainable Energy Systems (CSE), 5 Channel Center, Boston, MA 02210, USA 12King Abdulaziz City for Science and Technology (KACST), 17 King Abdullah Road, Riyadh, 11442, Saudi Arabia 13Centre Suisse d'Electronique et Microtechnique S.A. (CSEM), Rue Jaquet-Droz 1, Ch-2002 Neuchâtel, Switzerland 14Mitsui Chemicals, Inc., 580-32 Nagaura-cho, Sodegaura-shi, Chiba, 299-0265, Japan 15Suga Test Instruments Co., Ltd., 5-4-14 Shinjuku, Shinjuku-ku, 160-0022, Tokyo Japan Abstract — Reduced optical transmittance of encapsulants previously [1], [2], [3] —particularly after the incident at the resulting from ultraviolet (UV) degradation has frequently been Carrizo Plains concentrator installation [4]. The former identified as a cause of decreased PV module performance studies, e.g., [1], highlight the reduction in transmittance and through the life of service in the field. The present module safety the effect on characteristics including gel content and and qualification standards, however, apply short UV doses only chemistry for poly (ethylene-co-vinyl acetate) (EVA) capable of examining design robustness or “infant mortality” encapsulant. The latter studies, e.g., [2], [3], confirm that the failures. Essential information that might be used to screen encapsulation through product lifetime remains unknown. For degradation of EVA results from interactions and example, the relative efficacy of xenon-arc and UVA-340 incompatibilities between formulation additives. The module fluorescent sources or the typical range of activation energy for safety (IEC 61730) and qualification (IEC 61215 series) tests degradation is not quantified. We have conducted an presently apply to only a short (up to 137 days equivalent of interlaboratory experiment to provide the understanding that the IEC 60904-3 AM 1.5 global UV-B radiation dose) UV will be used towards developing a climate- and configuration- exposure. To establish module reliability for relevant, long- specific (UV) weathering test. Five representative, known term use, e.g., comparable to the desired lifetime of 25 years, formulations of EVA were studied in addition to one TPU requires greater understanding. material. Replicate laminated silica/polymer/silica specimens are We are conducting a set of experiments to provide the being examined at 14 institutions using a variety of indoor chambers (including Xenon, UVA-340, and metal-halide light understanding that will be used to develop weathering sources) or field aging. The solar-weighted transmittance, exposures for PV encapsulants that account for stresses in yellowness index, and the UV cut-off wavelength, determined different use environments, including different terrestrial from the measured hemispherical transmittance, are examined to climates and mounting configurations. The effort and results provide understanding and guidance for the UV light source for an initial set of work studying the degradation in optical (lamp type) and temperature used in accelerated UV aging tests. transmittance of encapsulants are described here. Other Index Terms — reliability, durability, thermal activation. portions of the work examine the effect of weathering on adhesion of glass to encapsulants or edge seals. Because no single institution had all of the resources to run the numerous I. INTRODUCTION exposure conditions, 15 institutions are collaborating in this The degradation of encapsulants used for photovoltaic (PV) work, as represented by the authors of this paper. modules subject to weather - the combined factors of light, The goals of this encapsulant transmittance study include: especially that in the ultraviolet (UV), temperature, and •Quantify the activation energies, Ea, for the degradation moisture (relative humidity, %RH) has been examined of transmittance. This includes providing a sense of the range 1 This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. of the Ea that may be present by examining “known bad,” baseline moisture concentration in the polymer similar to that “known good,” and “intermediate” material formulations. applied in indoor aging. Silica glass (transmitting above 202 •Determine if there is significant coupling between nm) was used rather than industry-standard soda-lime glass relevant stress factors, i.e., UV, temperature, and humidity. (transmitting above 295 nm), so that the glass would not This will identify what factors need to be considered in an attenuate UV radiation. accelerated test. Transmittance measurements were obtained at 0, 15, 30, 45, •Investigate the spectral requirements for different light 60, 75, 90, 120, and 180 days cumulative exposure. sources by comparing aged specimens, i.e., for Xe-arc, UVA- Transmittance measurements were obtained at the center and 340 fluorescent, and metal-halide
Load more

Recommended publications
  • Far Infrared Radiation Exposure
    INTERNATIONAL COMMISSION ON NON‐IONIZING RADIATION PROTECTION ICNIRP STATEMENT ON FAR INFRARED RADIATION EXPOSURE PUBLISHED IN: HEALTH PHYSICS 91(6):630‐645; 2006 ICNIRP PUBLICATION – 2006 ICNIRP Statement ICNIRP STATEMENT ON FAR INFRARED RADIATION EXPOSURE The International Commission on Non-Ionizing Radiation Protection* INTRODUCTION the health hazards associated with these hot environ- ments. Heat strain and discomfort (thermal pain) nor- THE INTERNATIONAL Commission on Non Ionizing Radia- mally limit skin exposure to infrared radiation levels tion Protection (ICNIRP) currently provides guidelines below the threshold for skin-thermal injury, and this is to limit human exposure to intense, broadband infrared particularly true for sources that emit largely IR-C. radiation (ICNIRP 1997). The guidelines that pertained Furthermore, limits for lengthy infrared exposures would to infrared radiation (IR) were developed initially with an have to consider ambient temperatures. For example, an aim to provide guidance for protecting against hazards infrared irradiance of 1 kW mϪ2 (100 mW cmϪ2)atan from high-intensity artificial sources and to protect work- ambient temperature of 5°C can be comfortably warm- ers in hot industries. Detailed guidance for exposure to ing, but at an ambient temperature of 30°C this irradiance longer far-infrared wavelengths (referred to as IR-C would be painful and produce severe heat strain. There- radiation) was not provided because the energy at longer fore, ICNIRP provided guidelines to limit skin exposure wavelengths from most lamps and industrial infrared to pulsed sources and very brief exposures where thermal sources of concern actually contribute only a small injury could take place faster than the pain response time fraction of the total radiant heat energy and did not and where environmental temperature and the irradiated require measurement.
    [Show full text]
  • Glossary of Terms
    GLOSSARY OF TERMS Terminology Used for Ultraviolet (UV) Curing Process Design and Measurement This glossary of terms has been assembled in order to provide users, formulators, suppliers and researchers with terms that are used in the design and measurement of UV curing systems. It was prompted by the scattered and sometimes incorrect terms used in industrial UV curing technologies. It is intended to provide common and technical meanings as used in and appropriate for UV process design, measurement, and specification. General scientific terms are included only where they relate to UV Measurements. The object is to be "user-friendly," with descriptions and comments on meaning and usage, and minimum use of mathematical and strict definitions, but technically correct. Occasionally, where two or more terms are used similarly, notes will indicate the preferred term. For historical and other reasons, terms applicable to UV Curing may vary slightly in their usage from other sciences. This glossary is intended to 'close the gap' in technical language, and is recommended for authors, suppliers and designers in UV Curing technologies. absorbance An index of the light or UV absorbed by a medium compared to the light transmitted through it. Numerically, it is the logarithm of the ratio of incident spectral irradiance to the transmitted spectral irradiance. It is unitless number. Absorbance implies monochromatic radiation, although it is sometimes used as an average applied over a specified wavelength range. absorptivity (absorption coefficient) Absorbance per unit thickness of a medium. actinometer A chemical system or physical device that determines the number of photons in a beam integrally or per unit time.
    [Show full text]
  • Princeton University Laser Safety Training Guide
    Laser Safety Training Guide Environmental Health and Safety http://www.princeton.edu/ehs September 2007 LASER SAFETY TRAINING GUIDE TABLE OF CONTENTS SECTION 1: LASER FUNDAMENTALS 3 LASER Theory And Operation 4 Components Of A Laser 5 Types Of Lasers 6 SECTION 2: LASER HAZARDS 8 BEAM-RELATED HAZARDS 8 Types of Beam Exposure 9 Eye 9 Skin 12 NON-BEAM HAZARDS 12 Electrical Hazards 13 Laser Generated Air Contaminants -- The “Plume” 14 Collateral and Plasma Radiation 14 Fire Hazards 15 Compressed Gases 15 Laser Dyes 15 SECTION 3: LASER HAZARD CLASSIFICATION 17 SECTION 4: LASER CONTROL MEASURES 19 Maximum Permissible Exposure (MPE) 19 Accessible Exposrue Limit 19 Optical Density (OD) 19 Nominal Hazard Zone (NHZ) 20 Control Measures by Laser Classification 21 Protective Equipment 27 Protective Eyewear 27 Laser Eye Protection Selection Process 27 Other Protective Equipment 28 Special Controls for UltraViolet and Infrared Lasers 29 SECTION 5: LASER SAFETY AT PRINCETON UNIVERSITY 30 SECTION 6: GLOSSARY 33 APPENDIX A: SELECTED ANSI STANDARD TABLES 36 APPENDIX B: LASER SAFETY TIPS 43 APPENDIX C: LASER SAFETY CHECKLIST 44 2 Section 1: LASER FUNDAMENTALS Introduction The word laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Lasers are used as research aides in many departments at Princeton University. In this document, the word laser will be limited to electromagnetic radiation-emitting devices using light amplification by stimulated emission of radiation at wavelengths from 180 nanometers to 1 millimeter. The electromagnetic spectrum includes energy ranging from gamma rays to electricity. Figure 1 illustrates the total electromagnetic spectrum and wavelengths of the various regions.
    [Show full text]
  • Laser Terms Glossary
    LASER TERMS GLOSSARY Texas State University – San Marcos 2/25/07 Risk Management & Safety LASER TERMS GLOSSARY Introduction - This section lists information pertinent to laser safety. The definitions in this glossary will not cover every term associated with lasers but does cover a majority of the terms. If a term should be encountered in your work with lasers and is not in this glossary, consult your supervisor or call the Texas State University Risk Management and Safety Office. Laser Terms ABSORPTION: means the transformation of radiant energy to a different form by interaction with matter. ACCESS CONTROL: Entry must be restricted to authorized laser personnel during the operation of laser equipment. ACCESSIBLE EMISSION LIMIT (AEL): - means the maximum accessible emission level permitted within a particular class. WAVELENGTH DURATION CLASS 1 CLASS 2 CLASS 3a CLASS 3b CLASS 4 (μm) (s) (W) (W) (W) (W) (W) Ultraviolet 0.18 to 0.302 3x104 ≤ 9.6x10-9 - Between 1 to 5 > Class 3a but > 0.5 0.302 to 0.4 3x104 ≤ 3.2x10-6 times Class 1 ≤ 0.5 Visible > Class 1 Less than 5 > Class 3a but 0.4 to 0.7 10 ≤ 0.4x10-3 > 0.5 but < 0.001 times Class 2 ≤ 0.5 Near IR ≤ 0.4x10-3 Between 1 to 5 > Class 3a but 0.7 to 1.05 ≥ 10 - > 0.5 to <1.9x10-3 times Class 1 ≤ 0.5 IR 1.05 to 1.15 ≤ 1.9x10-3 ≤ 1.9x10-3 Between 1 to 5 > Class 3a but 1.15 to 1.2 ≥ 10 - > 0.5 to 1.5x10-2 times Class 1 ≤ 0.5 1.2 to 1.4 ≤ 1.5x10-2 Far IR Between 1 to 5 > Class 3a but 1.4 to 100 ≥ 10 ≤ 9.6x10-3 - > 0.5 times Class 1 ≤ 0.5 AGENCY: means the Texas Department of State Health Services Radiation Control agency.
    [Show full text]
  • Radiometry and Photometry
    Radiometry and Photometry Wei-Chih Wang Department of Power Mechanical Engineering National TsingHua University W. Wang Materials Covered • Radiometry - Radiant Flux - Radiant Intensity - Irradiance - Radiance • Photometry - luminous Flux - luminous Intensity - Illuminance - luminance Conversion from radiometric and photometric W. Wang Radiometry Radiometry is the detection and measurement of light waves in the optical portion of the electromagnetic spectrum which is further divided into ultraviolet, visible, and infrared light. Example of a typical radiometer 3 W. Wang Photometry All light measurement is considered radiometry with photometry being a special subset of radiometry weighted for a typical human eye response. Example of a typical photometer 4 W. Wang Human Eyes Figure shows a schematic illustration of the human eye (Encyclopedia Britannica, 1994). The inside of the eyeball is clad by the retina, which is the light-sensitive part of the eye. The illustration also shows the fovea, a cone-rich central region of the retina which affords the high acuteness of central vision. Figure also shows the cell structure of the retina including the light-sensitive rod cells and cone cells. Also shown are the ganglion cells and nerve fibers that transmit the visual information to the brain. Rod cells are more abundant and more light sensitive than cone cells. Rods are 5 sensitive over the entire visible spectrum. W. Wang There are three types of cone cells, namely cone cells sensitive in the red, green, and blue spectral range. The approximate spectral sensitivity functions of the rods and three types or cones are shown in the figure above 6 W. Wang Eye sensitivity function The conversion between radiometric and photometric units is provided by the luminous efficiency function or eye sensitivity function, V(λ).
    [Show full text]
  • EL for Broadband Optical Radiation Karl Schulmeister ICNIRP SC-IV Member Seibersdorf Laboratories, Austria
    ICNIRP 7th International NIR Workshop Edinburgh, United Kingdom, 9-11 May 2012 EL for Broadband Optical Radiation Karl Schulmeister ICNIRP SC-IV Member Seibersdorf Laboratories, Austria Broadband Optical Radiation Karl Schulmeister ICNIRP 7th International NIR Workshop Edinburgh, United Kingdom, 9-11 May 2012 100 nm ~400 nm 780 nm 1 mm UV vis IR Broadband Optical Radiation Karl Schulmeister ICNIRP 7th International NIR Workshop Edinburgh, United Kingdom, 9-11 May 2012 Exposure Limits •UV –s() • UV-A • Retina photochemical • Retina thermal •Infraredeye • Skin (vis. and IR) Photographs courtesy of P Söderberg JP Cesarini and Univ. Michigan, Kellogg Eye Center Broadband Optical Radiation Karl Schulmeister ICNIRP 7th International NIR Workshop Edinburgh, United Kingdom, 9-11 May 2012 Exposure Limits •UV –s() • UV-A • Retina photochemical • Retina thermal • Infrared eye • Skin (vis. and IR) Broadband Optical Radiation Karl Schulmeister ICNIRP 7th International NIR Workshop Edinburgh, United Kingdom, 9-11 May 2012 Current Guidelines: ICNIRP Guidelines on limits of exposure to broad-band incoherent optical radiation (0.38-3µm) Health Phys. 73: 539-554; 1997 New Edition of Guidelines for visible and IR: Open Consultation 2011 Health Physics Publication: End 2012/Beginning 2013 Product Standards updated in parallel: CIES009/ IEC 62471 (Lamp Product Safety Standard) IEC 60825-1 (Laser Product Safety Standard) Broadband Optical Radiation Karl Schulmeister ICNIRP 7th International NIR Workshop Edinburgh, United Kingdom, 9-11 May 2012 Absorption location and mechanism overview •UV-C, B •UV-A P H O T O- •vis C H E M I C A L E = h * •IR-A •IR-B, C T H E R M A L Broadband Optical Radiation Karl Schulmeister ICNIRP 7th International NIR Workshop Edinburgh, United Kingdom, 9-11 May 2012 Changes in Guidelines .
    [Show full text]
  • Radtech Buyers Guide
    UV Glossary Feature of Terms Terminology Used for Ultraviolet (UV) Curing Process Design and Measurement This glossary of terms has been assembled in order to provide users, formulators, suppliers and researchers with terms that are used in the design and measurement of UV-curing systems. It was prompted by the scattered and sometimes incorrect terms used in industrial UV-curing technologies. It is intended to provide common and technical meanings as used in and appropriate for UV process design, measurement and specification. General scientific terms are included only where they relate to UV Measurements. The object is to be “user-friendly,” with descriptions and comments on meaning and usage, and minimum use of mathematical and strict definitions, but technically correct. Occasionally, where two or more terms are used similarly, notes will indicate the preferred term. For historical and other reasons, terms applicable to UV curing may vary slightly in their usage from other sciences. This glossary is intended to “close the gap” in technical language, and is recommended for authors, suppliers and designers in UV-curing technologies. absorbance had small amounts of metal halide(s) wavelengths (IR) are called “cold An index of the light or UV absorbed added to the mercury within the bulb. mirrors,” while reflectors having by a medium compared to the light These materials will emit their character- enhanced reflectance to long transmitted through it. Numerically, it is istic wavelengths in addition to the wavelengths are called “hot mirrors.” the logarithm of the ratio of incident mercury emissions. [This term is diffuse spectral irradiance to the transmitted preferred over doped lamps.] A characteristic of a surface that spectral irradiance.
    [Show full text]
  • Glossary of Laser Terms Absorb to Transform Radiant Energy Into a Different Form, with a Resultant Rise in Temperature. Absorpt
    Glossary of Laser Terms Absorb To transform radiant energy into a different form, with a resultant rise in temperature. Absorption Transformation of radiant energy to a different form of energy by the interaction with matter, depending on temperature and wavelength. Accessible Emission Level The magnitude of accessible laser (or collateral) radiation of a specific wavelength or emission duration at a particular point as measured by appropriate methods and devices. Also means radiation to which human access is possible in accordance with the definitions of the laser's hazard classification. Accessible Emission Limit (AEL) The maximum accessible emission level permitted within a particular class. In ANSI Z 136.1, AEL is determined as the product of accessible emission Maximum Permissible Exposure limit (MPE) and the area of the limiting aperture (7 mm for visible and near-infrared lasers). Aperture An opening through which radiation can pass. Argon A gas used as a laser medium. It emits blue-green light primarily at 448 and 515 nm. Attenuation The decrease in energy (or power) as a beam passes through an absorbing or scattering medium. Aversion Response Movement of the eyelid or the head to avoid an exposure to a noxious stimulant, bright light. It can occur within 0.25 seconds, and it includes the blink reflex time. Beam A collection of rays that may be parallel, convergent, or divergent. Beam Diameter The distance between diametrically opposed points in the cross section of a circular beam where the intensity is reduced by a factor of e-1 (0.368) of the peak level (for safety standards).
    [Show full text]
  • LUXEON IR Family Eye Safety Assembly and Handling Guidelines
    INFRARED LUXEON IR Family Eye Safety Assembly and Handling Guidelines Introduction Light Emitting Diodes (LEDs) are becoming the standard light source for illumination infrared (IR) applications. High power LEDs have a high optical radiating power and a small light emitting surface, resulting in brightness of the light emission surface that is significant with respect to the lamps safety standard. The IEC-62471:2006 standard “Photobiological safety of lamps and lamp systems” is applicable when considering the eye and skin safety impact by LEDs. This application brief covers LEDs and lamps with IR wavelengths. The standard (IEC-62471:2006) defines exposure limits (EL) for eye and skin which depend on exposure duration and on whether a lamp emits in continuous or pulsed mode. Depending on the radiating power and brightness, lamps and LEDs are categorized into risk groups. Depending on the risk group classification, the manufacturer may need to put warning labels on products and\or packaging and include instructions for users. In this application brief some examples are given on how to classify the risk group. It gives an overview of the IEC-62471 standard and does not necessarily cover all application conditions. For final product classification and eye safety certification, the manufacturer should check with accredited laboratories that can assist in the exact classification of the product with IR LEDs. This application brief will focus on IR-A (700nm-1000nm) radiation and contains examples of exposure limit calculations. As the focus is on IR exposure, the photochemical hazards from UV, blue light and retinal blue hazard are assumed to be negligible.
    [Show full text]
  • Radiometric Quantities and Units Used in Photobiology And
    Photochemistry and Photobiology, 2007, 83: 425–432 Radiometric Quantities and Units Used in Photobiology and Photochemistry: Recommendations of the Commission Internationale de l’Eclairage (International Commission on Illumination) David H. Sliney* International Commission on Illumination (CIE), Vienna, Austria and Laser ⁄ Optical Radiation Program, US Army Center for Health Promotion and Preventive Medicine, Gunpowder, MD Received 14 November 2006; accepted 16 November 2006; published online 20 November 2006 DOI: 10.1562 ⁄ 2006-11-14-RA-1081 ABSTRACT The International Commission on Illumination, the CIE, has provided international guidance in the science, termi- To characterize photobiological and photochemical phenomena, nology and measurement of light and optical radiation since standardized terms and units are required. Without a uniform set 1913. The International Lighting Vocabulary (parts of which of descriptors, much of the scientific value of publications can be are also issued as an ISO or IEC standard) has been an lost. Attempting to achieve an international consensus for a international reference for photochemists and photobiolo- common language has always been difficult, but now with truly gists for many decades; and the next revision is due to be international scientific publications, it is all the more important. published later this year or next (2). Despite its stature, As photobiology and photochemistry both represent the fusion of many research scientists are unfamiliar with some of the several scientific disciplines, it is not surprising that the physical subtle distinctions between several widely used radiometric terms used to describe exposures and dosimetric concepts can terms. Tables 1–4 provide several standardized terms that vary from author to author.
    [Show full text]
  • Terms and Units of Itfeasure · the International System of Units'(SI}
    AppendlxA Terms and Units of Itfeasure · The International System of Units'(SI} The International System of Units, abbreviated SI, as defmed in International Standard ISO 1000, is described in this appendix. International Standard ISO 1000 was approved by International Organization of Standards (ISO) Member Bodies from 30 countries including the United States. The SI consists of the following: 1. Seven base units 2. AlI the derived units 3. Two supplementary units 4. The series of approved prefixes for multiples and submultiples of units. The units which apply to optical safety, their defmitions, their symbols, and the for­ mation of multiple and submultiple units are presented in this appendix. Informa­ tion related to style, use, and format is also provided. A.l TIlE TIlREE CLASSES OF UNITS IN TIlE SI The units of the International System of Units are divided into three classes: 1. Base units 2. Derived units 3. Supplementary units. Scientifically and technical1y this classification is partially arbitrary. The 10th General Conference of Weights and Measures (1954) adopted as base units ofthe SI the units of the quantities: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity which by convention are regarded as dimensional1y independent. Associated with these quantities are seven well-defmed units. This action was taken in the interest of achieving the advantages of having a single, practical, internationally accepted system for trade, education, science, and technology. The derived units are the units of quantities that can be formed by combining base quantities and other derived quantities according to the rules of algebra.
    [Show full text]
  • The International System of Units (SI) in Oceanography; Unesco Technical
    Unesco technical papers in marine science 45 IAPSO Publication Scientifique No. 32 The International System of Units (SI) in Oceanography Report of IAPSO Working Group on Symbols, Units and Nomenclature in Physical Oceanography (SUN) This report was prepared under the auspices of the Inter­ national Association for the Physical Sciences of the Ocean (IAPSO). The first part is a revised version of IAPSO Publication Scientifique No. 31 (SUN Report). Unesco 1985 ' - i Published in 1985 by the United Nations Educational, Scientific and Cultural Organization, Place de Fontenoy, 75700 Paris. Printed in Unesco’s workshops. © Unesco 1985 Printed in France Reproduction authorized, providing that appropriate mention is made of Unesco Technical Papers in Marine Science and voucher copies are sent to the Division of Marine Sciences. PREFACE This series, the Unesco Technical Papers in Marine Science, is produced by the Unesco Division of Marine Sciences as a means of informing the scientific community of recent developments in oceanographic research and marine science affairs. Many of the texts published within the series result from research activities of the Scientific Committee on Oceanic Research (SCOR) and are submitted to Unesco for printing following final approval by SCOR of the relevant working group report. Unesco Technical Papers in Marine Science are distributed free of charge to various institutions and governmental authorities. Requests for copies of individual titles or additions to the mailing list should be addressed, on letterhead stationery if possible, to : Division of Marine Sciences, Unesco, Place de Fontenoy, 75700 Paris, France. XVI GENERAL ASSEMBLY OF THE INTERNATIONAL ASSOCIATION FOR THE PHYSICAL SCIENCES OF THE OCEAN (IAPSO) GRENOBLE, FRANCE, AUGUST 1975 RESOLUTION No 6 - 1975 IAPSO recommends the use of SI units and symbols in physical oceanography.
    [Show full text]