List of TablesTable 2.1 Chronology of definitions of the metre since 1795 5 Table 2.2 Adoption and compulsory implementation dates for the metric system 7 Table 2.3 Timetable of the majo
Trang 2Francois Cardarelli
Encyclopaedia of Scientific Units, Weights and
Measures
Their SI Equivalences and Origins
English translation by MJ Shields, FIInfSc, MITI
Springer
Trang 3Member of ACS, AlChE, ASM, TMS, and OCQ
Principal Chemist, Materials
RIO TINTO Iron & Titanium Inc.
Consultant in Electrochemical Engineering
44, rue de Ia Cosarde F-94240 L'Hay-les-Roses, France
1966-Encydopaedia of scientific units, weights and measures:
their SI equivalences and origins
1 Mensuration Conversion tables 2 Metric system
1966-Encydopaedia of scientific units, weights, and measures: their SI equivalences and
origins / Francois Cardarelli.
p cm.
Includes bibliographical references.
ISBN 1-85233-682-X (alk paper)
1 Metric system-Conversion tables-Handbooks, manuals, etc 2 Units-Handbooks,
manuals, etc I Title.
QC94.C295 2003
530.8'12-dc21 2003045428
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency Enquiries concerning reproduction outside these terms should be sent to the publishers.
ISBN 1-85233-682-X
Springer Science+Business Media
springeronline.com
© Springer-Verlag London Limited 2003
Printed in the United States of America
4th printing 2006
The use of registered names, trademarks, etc in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore free for general use The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made.
Typeset by T&A Typesetting Services, Rochdale, England
69/3830-543 Printed on acid-free paper SPIN 11525592
Trang 4Encyclopaedia of Scientific Units, Weights and Measures is dedicated to my parents
Antonio and Claudine, to my sister Elsay and to Louise Saint-Amour, for their love and
support
Francois Cardarelli
Acknowledgments
Mr Jean-Etienne Mittelmann, Mr Nicholas Pinfield and Mr Nicolas Wilsony are gratefully
acknowledged for their valued assistance, patience, and advice.
Many thanks to the numerous readers of the first and second editions who provided me with their useful comments and remarks by returning the bookmarks filled with their suggestions.
Trang 5Author Biography
Francis Cardarelli
Born in Paris XV, France, February 17, 1966
Academic Background
Ph.D in Chemical Engineering (Univ Paul Sabatier, Toulouse III, 1996)
M.Sc in Electrochemical Engineering (Univ P & M Curie, Paris VI, 1992)
B.Sc in Physical Chemistry and Nuclear Engineering (Univ P & M Curie/CNAM, Paris VI, 1990)
Associate Degree in Geophysics and Geology (Univ P & M Curie, Paris VI, 1987) Baccalaureate C (Maths-Physics-Chem.) (CNEC, Versailles, 1985)
Working Areas
The successive working areas since 1990 are in chronological order: (1) Research scientist
at the Laboratory of Electrochemistry (University P & M Curie, Paris, France) for the development of a nuclear detector used for electrochemical experiments involving radio- labelled compounds (2) Research scientist at the Institute of Marine Biogeochemistry (CNRS & Ecole Normale Superieure, Paris, France) for the environmental monitoring of heavy metals in natural waters by electroanalytical techniques (3) Research scientist for the preparation by molten salts electrochemistry of tantalum coatings for the chemical process industries and for the preparation and characterization of industrial electrodes at the Laboratory of Chemical Engineering (Univ Paul Sabatier, Toulouse, France) (spon- sored by Electricite de France) (4) Registered consultant in electrochemical engineering (Toulouse, France) (5) Materials expert and industrial electrochemist at the Lithium Dept.
of ARGOTECH Productions, Inc (Boucherville, Canada) involved in the metallurgy and processing of lithium metal anodes and for the development of a recycling process for spent lithium metal solid polymer electrolyte batteries (6) Materials expert and industrial electrochemist at the Technology Dept of AVESTOR (Boucherville, Canada) in charge of the sourcing and qualification of strategic raw materials entering in the fabrication of lithium metal solid polymer electrolyte batteries (7) Materials specialist in the Pyrome- tallurgy group at the Technology Dept of RIO TINTO Iron & Titanium Inc (Sorel-Tracy, Canada) (8) Principal chemist in the TiO2 products group at the Technology Dept of RIO TINTO Iron & Titanium Inc (Sorel-Tracy, Canada).
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Contents
Dedication v
Acknowledgments v
Author Biography vi
Academic Background vi
Working Areas vi
List of Tables xvii
1 Introduction 1
1.1 Why a Conversion Handbook? 1
1.2 How to Use This Book 2
2 The International System of Units 3
2.1 History 3
2.2 The General Conference on Weights and Measures 6
2.3 Organization of the SI 10
2.3.1 SI Base Units 10
2.3.2 SI Supplementary Units 12
2.3.3 SI Derived Units 13
2.3.4 Non-SI and SI Units Used in Combination 14
2.3.4.1 Commonly Used Legal Non-SI Units 14
2.3.4.2 Non-SI Units Defined by Experiment 14
2.3.4.3 Non-SI Units Temporarily Maintained 15
2.3.4.4 Non-SI Units Which Must Be Discontinued 15
2.4 SI Prefixes 15
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3 Other Systems of Units 19
3.1 MTS, MKpS, MKSA 19
3.1.1 The MKpS System 19
3.1.2 The MTS System 19
3.1.3 The MKSA (Giorgi) System 20
3.2 Cgs, Gauss, IEUS, a.u 20
3.2.1 The cgs System 20
3.2.1.1 The esu Subsystem 21
3.2.1.2 The emu Subsystem 21
3.2.2 The Gauss System 22
3.2.3 International Electrical Units 25
3.2.4 Atomic Units (a.u.) 25
3.3 British and American Systems of Units 26
3.3.1 Imperial Units 26
3.3.1.1 Imperial Units of Length 28
3.3.1.1.1 UK Linear Measure 29
3.3.1.1.2 UK Nautical Measure 29
3.3.1.1.3 UK Surveyors’ Measure 31
3.3.1.2 Imperial Units of Area 31
3.3.1.2.1 UK Measures of Area 32
3.3.1.2.2 UK Surveyors' Measure 32
3.3.1.2.3 Circular Units 32
3.3.1.3 Imperial Units of Volume and Capacity 33
3.3.1.3.1 UK Measures of Volume 33
3.3.1.3.2 UK Liquid Measure 34
3.3.1.3.3 UK Dry Measure 34
3.3.1.4 Imperial Units of Weight 34
3.3.1.4.1 UK Avoirdupois Weight 34
3.3.1.4.2 UK Apothecaries’ Weight 38
3.3.1.4.3 UK Troy Weight 38
3.3.2 The American System of Measures (US Customary Units) 39
3.3.2.1 US Customary Units of Length 39
3.3.2.1.1 US Linear Measure 39
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This page has been reformatted by Knovel to provide easier navigation 3.3.2.1.2 US Nautical Measure 40
3.3.2.1.3 US Surveyors’ Measure 40
3.3.2.2 US Customary Units of Area 40
3.3.2.2.1 US Measures of Area 40
3.3.2.2.2 US Surveyors’ Measure 41
3.3.2.2.3 Circular Units 42
3.3.2.3 US Units of Volume and Capacity 42
3.3.2.3.1 US Measures of Volume 42
3.3.2.3.2 US Liquid Measure 42
3.3.2.3.3 US Dry Measure 42
3.3.2.3.4 US Apothecaries’ Measures of Capacity 44
3.3.2.4 US Customary Units of Weight 44
3.3.2.4.1 US Avoirdupois Weight 44
3.3.2.4.2 US Apothecaries’ Weight 44
3.3.2.4.3 US Troy Weight 45
3.3.3 Obsolete Weight and Capacity Measures 46
3.3.3.1 UK Units of Weight for Butter and Cheese 46
3.3.3.2 UK Units for Beer, Wines, and Spirits 46
3.3.3.3 UK Units of Weight for Coal 47
3.3.3.4 UK Units for Clothes 47
3.3.3.5 UK and US Hay and Straw Weights 49
3.3.3.6 UK Weight for Wool 49
3.3.3.7 US Units of Capacity Used in Food Recipes 49
3.3.3.8 US Units of Capacity for Wine 49
3.3.3.9 Modern UK and US Dimensionless Units for Numbers of Paper Sheets 51
3.3.3.10 Old UK and US Dimensionless Units for Numbers of Paper Sheets 51
3.3.3.11 Old US Units for Measuring the Volume of Stacked Firewood 51
3.3.3.12 UK and US Dimensionless Counting Units 51
3.4 The Foot-pound-second (FPS) System 51
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3.5 Ancient and Obsolete Systems of Weights and Measures 55
3.5.1 Systems from Antiquity 56
3.5.1.1 The Chinese System 57
3.5.1.1.1 Old Chinese Units of Length 57
3.5.1.1.2 Old Chinese Units of Area 57
3.5.1.1.3 Old Chinese Units of Weight 57
3.5.1.1.4 Old Chinese Units of Capacity 57
3.5.1.2 The Indian System 61
3.5.1.2.1 Old Indian Units of Length 61
3.5.1.2.2 Indian Units of Weight 61
3.5.1.2.3 Indian Units of Capacity 61
3.5.1.3 The Egyptian System 61
3.5.1.3.1 Egyptian Units of Length 61
3.5.1.3.2 Egyptian Units of Area 61
3.5.1.3.3 Egyptian Units of Weight 65
3.5.1.3.4 Egyptian Units of Capacity 65
3.5.1.4 The Assyrio-Chaldean-Persian System 65
3.5.1.4.1 Persian Units of Length 65
3.5.1.4.2 Persian Units of Area 65
3.5.1.4.3 Persian Units of Weight 67
3.5.1.4.4 Persian Units of Capacity 67
3.5.1.5 The Hebrew System 67
3.5.1.5.1 Hebrew Units of Length 67
3.5.1.5.2 Hebrew Units of Weight (Sacred System) 67
3.5.1.5.3 Hebrew Units of Weight (Talmudic or Rabbinical System) 68
3.5.1.5.4 Hebrew Units of Capacity (Dry) 68
3.5.1.5.5 Hebrew Units of Capacity (Liquids) 68
3.5.1.6 The Greek System (Attic) 68
3.5.1.6.1 Greek Units of Length 68
3.5.1.6.2 Greek Units of Weight 70
3.5.1.6.3 Greek Units of Capacity (Dry) 70
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This page has been reformatted by Knovel to provide easier navigation 3.5.1.6.4 Greek Units of Capacity (Liquids) 70
3.5.1.7 The Roman System 70
3.5.1.7.1 Roman Units of Length 70
3.5.1.7.2 Roman Units of Area 70
3.5.1.7.3 Roman Units of Weight 73
3.5.1.7.4 Roman Units of Capacity (Dry) 73
3.5.1.7.5 Roman Units of Capacity (Liquids) 73
3.5.1.8 The Arabic System 73
3.5.1.8.1 Arabic Units of Length 73
3.5.1.8.2 Arabic Units of Area 73
3.5.1.8.3 Arabic Units of Weight (System of the Prophet) 73
3.5.1.8.4 Arabic Units of Capacity 73
3.5.2 Obsolete National and Regional Systems 73
3.5.2.1 Western and Southern Europe 73
3.5.2.1.1 Old French System (Ancien Regime) 73
3.5.2.1.2 Old French System (1812-1840) 83
3.5.2.1.3 Old Belgian System 83
3.5.2.1.4 Old Swiss System 84
3.5.2.1.5 Old Scottish System 85
3.5.2.1.6 Old Irish System 86
3.5.2.1.7 Old Italian System 87
3.5.2.1.8 Old Spanish System (Castillian) 88
3.5.2.1.9 Old Portuguese System 90
3.5.2.1.10 Old Maltese System 93
3.5.2.1.11 Old Balearic Islands System 94
3.5.2.1.12 Old Greek System 95
3.5.2.1.13 Old Cypriot System 96
3.5.2.1.14 Old Turkish System 97
3.5.2.2 Central and Northern Europe 99
3.5.2.2.1 Old Austrian System 99
3.5.2.2.2 Old German System (Prussian) 100
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3.5.2.2.3 Old Yugoslavian System 103
3.5.2.2.4 Old Czechoslovakian System 104
3.5.2.2.5 Old Hungarian System 105
3.5.2.2.6 Old Romanian System 105
3.5.2.2.7 Old Dutch System 106
3.5.2.2.8 Old Danish System 107
3.5.2.2.9 Old Polish System 109
3.5.2.2.10 Old Swedish System 112
3.5.2.2.11 Old Norwegian System 116
3.5.2.2.12 Old Finnish System 116
3.5.2.2.13 Old Icelandic System 117
3.5.2.2.14 Old Estonian System 117
3.5.2.2.15 Old Latvian System 119
3.5.2.2.16 Old Russian System 120
3.5.2.3 Africa 122
3.5.2.3.1 Old Moroccan System 122
3.5.2.3.2 Old Algerian System 125
3.5.2.3.3 Old Tunisian System 126
3.5.2.3.4 Old Libyan System 127
3.5.2.3.5 Old Egyptian System 128
3.5.2.3.6 Old Abyssinian System 130
3.5.2.3.7 Old Eritrean System 131
3.5.2.3.8 Old Ethiopian System 131
3.5.2.3.9 Old Somalian System 132
3.5.2.3.10 Old Guinean System 132
3.5.2.4 Middle East and Asia 135
3.5.2.4.1 Old Saudi-Arabian System 135
3.5.2.4.2 Old Persian System 136
3.5.2.4.3 Old Syrian System 138
3.5.2.4.4 Old Turkmenian System 138
3.5.2.4.5 Old Indian System 139
3.5.2.4.6 Old Burmese System 139
3.5.2.4.7 Old Ceylonese and Madrasian System 143
3.5.2.4.8 Old Annamese System 144
3.5.2.4.9 Old Cambodian System 144
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This page has been reformatted by Knovel to provide easier navigation 3.5.2.4.10 Old Thai System 146
3.5.2.4.11 Old Indonesian System 151
3.5.2.4.12 Old Philippine System 151
3.5.2.4.13 Old Japanese System 153
3.5.2.5 Central and South America 156
3.5.2.5.1 Old Cuban System 156
3.5.2.5.2 Old Haitian System 156
3.5.2.5.3 Old Honduran, Costa-Rican, Nicaraguan, Salvadoran, and Guatemalan System 157
3.5.2.5.4 Old Venezuelan System 158
3.5.2.5.5 Old Colombian System 158
3.5.2.5.6 Old Brazilian System 159
3.5.2.5.7 Old Paraguayan System 160
3.5.2.5.8 Old Argentinian System 161
3.5.2.5.9 Old Chilean System 162
3.5.2.5.10 Old Peruvian System 163
3.5.2.6 North America 164
3.5.2.6.1 Old Mexican System 164
4 Conversion Tables 167
4.1 Units in Alphabetical Order 167
4.1.1 a.u of Action to Acetabulum (Roman) 171
4.1.2 Achir (Qasaba) to Akey (Guinean) 174
4.1.3 Ako (Hungarian) to Ampere per Square Inch 179
4.1.4 Ampere per Square Metre to Ardeb (Abyssinian, Long) 185
4.1.5 Ardeb (Egyptian) to Atmosphere Cubic Foot per Min 190
4.1.6 Atmosphere Cubic Metre per Hour to Baker's Dozen 196
4.1.7 Bale (Brazilian, Cotton) to Baromil 202
4.1.8 Barony (US) to Batman (Turkish) 207
4.1.9 Batman (Turkmenian) to Bes (Roman) 213
4.1.10 Bigha (India) to Bokard (Saudi Arabian) 219
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4.1.11 Bole to Brig 224
4.1.12 Brill to Button (UK) (UK Line) 229
4.1.13 Button (US) (US Line) to Calemin (Spanish, Dry) 236
4.1.14 Calibre (Centiinch) to Cantaro (Tunisian, Attari) 241
4.1.15 Cantaro (Tunisian, Khaddari) to Celo 248
4.1.16 Celsius Degree to Chain (Scottish) 254
4.1.17 Chain (UK, Nautical) Tochopine (Provence, Wine) 260
4.1.18 Chopine (Scottish, liq.) to Coefficient of Performance 265
4.1.19 Coffee Measure (US) to Covid (Ceylon) 270
4.1.20 Covid (Indian, Bombay) to Cubic Foot per UK Ton 275
4.1.21 Cubic Gigametre to Daneq (Arabic) 281
4.1.22 Daniell to Dextre (Montpellier) 288
4.1.23 Dha (Burmese) to Dots (Points) per Inch 296
4.1.24 Double Pace (US, Military) to Duime (Russian Inch) 302
4.1.25 Dung (Persian) to Endere (Romanian) 309
4.1.26 Energy Efficiency Rating to Fanega (Cuban) 315
4.1.27 Fanega (Guatemalan) to Fen (Chinese) 322
4.1.28 Feralin (Icelandic) to Fod (Norwegian) 328
4.1.29 Foot to Fotmal (UK, Lead) 336
4.1.30 Fourier to Gallon (US, Liq.) 343
4.1.31 Gallon (US) per Day per Capita to Gill (US, Liq.) 350
4.1.32 Giornata (Italian) to Guz (Indian, Bombay) 357
4.1.33 Guz (Indian, Calcutta) to Hekatomb (Greek) 364
4.1.34 Hektos (Greek, Attic) to Inch of Mercury (60°F) 371
4.1.35 Inch of Rainfall to Jun (Chinese) (Kwan) 379
4.1.36 Jungfru (Swedish) to Khous (Greek Gallon) 387
4.1.37 Kieselgur Unit to Kiyak-kin (Japanese) 395
4.1.38 Klafter (Austrian) [Austrian Fathom] to Kwarta (Polish) 401
4.1.39 Kwarterka (Polish) to Legua (Mexican) 407
4.1.40 Legua (Paraguayan) to Light-year (Annee-lumiere) 414
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This page has been reformatted by Knovel to provide easier navigation 4.1.41 Ligne (de Paris) (French Line) to Lockie (Polish, Cracow) 420
4.1.42 Lockie (Polish, New) to Mach 426
4.1.43 Mache Unit to Marok (Hungarian) 432
4.1.44 Marta (Libyan) to Mesh 438
4.1.45 Mesh to Mignonette (French) 444
4.1.46 Mignonne to Millia (Roman) [Roman Mile] 450
4.1.47 Milliampere per Square Centimetre to Miner's Inch 456
4.1.48 Mingelen (Dutch) to Mole per Litre 462
4.1.49 Momme to Nautical Mile (International) 468
4.1.50 Nautical Mile (UK) to Nox 474
4.1.51 Noy to Ohm (Mechanical, SI) 480
4.1.52 Ohm (Prussian) to Ottingkar (Danish, Dry) 486
4.1.53 Oukia (Arabic) to Palestra (Greek, Attic) [Greek Palm] 492
4.1.54 Paletz (Russian) to Payok (Russian, Dry) 498
4.1.55 Pe (Brazilian) to Perm (23°C) 504
4.1.56 Perm-inch (0°C) to Picul (Chinese) 510
4.1.57 Picul (Indonesian) to Pipa (Spanish) 516
4.1.58 Pipe (Danish, Liq.) to Pond (Amsterdam) 522
4.1.59 Pond (Dutch) [Dutch Pound] to Pound (UK, Straw) 528
4.1.60 Pound (UK, Mercantile) to Pulgada (Spanish) 534
4.1.61 Pulgada (Venezuelan) to Quart (US, Dry) 540
4.1.62 Quart (US, Liquid) to Quinto (Guinean) 546
4.1.63 Quinze-seize (de Paris) to Register Ton (UK) 552
4.1.64 Rehoboam (Rehoboam) to Rottolo (Somalian) 558
4.1.65 Rottolo (Syrian) to Salinity of Seawater 565
4.1.66 Salma (Maltese) to Scruple (Swiss, Apothecary) 571
4.1.67 Scruple (UK Fluid) to Sextarius (Roman, Liq.) 577
4.1.68 Sextarius (Roman, Dry) to Sir (Turkmenian) 583
4.1.69 Siriometre to Square (UK, US) 589
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4.1.70 Square (Cubic Metre) per Square Mole to Square
Picometre 596
4.1.71 Square Plethron (Attic) to Stang (Welsh) 602
4.1.72 Stapp to Stringene (Romanian) 608
4.1.73 Strob to Tarri (Algerian) 614
4.1.74 Tassoo (Indian, Bombay) to Thang (Cambodian) 620
4.1.75 That (Annamese) to Toise (Swiss) 627
4.1.76 Toise Cube (Haitian) to Tonelada (Spanish) 633
4.1.77 Tonelada (Venezuelan) to Tun (UK, Beer) 639
4.1.78 Tun (US, Liq.) to Vara (Argentinian) 645
4.1.79 Vara (Brazilian) to Volume Unit 651
4.1.80 Voxel to Wloka (Polish, Warsaw) 657
4.1.81 Woebe (Persian) to Yen (Annamese) 663
4.1.82 Yin (Chinese) [Yan] to Zuzah (Hebrew) [Talmudic System] 669
4.2 Conversion Tables Listed by Physical Quantities 674
4.2.1 Conversion Tables for Units of Mass 674
4.2.2 Conversion Tables for Units of Length 684
Table 4.2.2.1 Conversion Table: Units of Length: Multiples and Submultiples (SI) 684
Table 4.2.2.2 Conversion Table: Units of Length (>1 m) 686
Table 4.2.2.3 Conversion Table: Units of Length (<1 m) 690
Table 4.2.2.4 Conversion Table: Units of Length (Typography) 694
4.2.3 Conversion Tables for Units of Area 695
4.2.4 Conversion Tables for Units of Volume and Capacity 702
4.2.5 Conversion Table for Units of Linear Density 708
4.2.6 Conversion Table for Units of Surface Mass Density 709
4.2.7 Conversion Table for Units of Mass Density 710
4.2.8 Conversion Table for Units of Specific Gravity 712
4.2.9 Conversion Table for Units of Time 714
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This page has been reformatted by Knovel to provide easier navigation 4.2.10 Conversion Table for Units of Dynamic Viscosity 716
4.2.11 Conversion Table for Units of Kinematic Viscosity 717
4.2.12 Conversion Table for Units of Linear Velocity 718
4.2.13 Conversion Table for Units of Angular Velocity 720
4.2.14 Conversion Table for Units of Force 722
4.2.15 Conversion Table for Units of Pressure and Stress 724
4.2.16 Conversion Table for Units of Energy, Heat and Work 728
4.2.17 Conversion Table for Units of Power 730
4.2.18 Conversion Table for Units of Plane and Solid Angle 734
4.2.19 Conversion Table for Units of Thermal Conductivity 736
4.2.20 Conversion Tables for Units of Concentration 738
4.2.21 Conversion Table for Units of Temperature 740
4.2.22 Conversion Table for Electrical Units 741
4.2.23 Conversion Table for Units Used in Magnetism 742
4.2.24 Conversion Table for Photometric Units 743
4.2.25 Conversion Table for Units Used in Nuclear Sciences 744
4.2.26 Conversion Table for Energy Equivalents for Electromagnetic Radiation 745
4.2.27 Conversion Table for Ideal Gas Constant in Various Units 746
4.2.28 Conversion Table for Dimensions for Permeability Coefficients 747
4.2.29 Conversion Table for International Kinematic Viscosity Indices 748
4.2.30 Conversion Table for Standard Sieve Designation Series 751
4.2.31 Conversion Table for International Standard Wire and Sheet Gauges 755
4.2.32 Conversion Table for Normal Pipe Sizes 759
4.2.32.1 Nominal Pipe Sizes: 1/8 to 12 759
4.2.32.2 Nominal Pipe Sizes: 14 to 42 765
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5 Fundamental Constants 771
5.1 Fundamental Mathematical Constants 771
5.2 Fundamental Physical Constants 772
6 Appendices 781
6.1 Greek Alphabet 781
6.2 Roman Numerals 781
6.3 Rules about Large Numbers (>1 000 000) 782
6.4 Date and Time Numerical Representation 783
6.5 National, Regional and International Standardization Bodies 783
6.5.1 International Standards Bodies 784
6.5.2 National Standards Bodies Worldwide 785
6.5.2.1 National Standards Bodies 785
6.5.2.1.1 ABBS to INDECOPI 785
6.5.2.1.2 INEN to ZSM 792
6.5.2.2 US Standards and Standardizations Bodies, Technical Associations and Societies 800
6.5.2.2.1 AA to CDA 800
6.5.2.2.2 DIS to USPTO 806
6.6 Acceleration Due to Gravity at any Latitude and Elevation 811
6.7 International Practical Temperature Scale (IPTS, 1968) 812
6.8 International Temperature Scale (ITS-90) 813
6.9 French-English Lexicon for Units 814
6.10 French-English Lexicon for Physical Quantities 816
6.11 International Clothing and Shoe Sizes (US, UK, Europe, and Japan) 819
6.12 Common Time Acronyms 822
6.13 Old Alchemical Symbols Used in Astronomy, Chemistry, and Biology 822
6.14 International Geological Time Scale 823
6.15 Old Symbols Used in the British System 826
6.16 Electromagnetic Spectrum 827
6.17 Standard Paper Sizes (ISO and US) 827
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This page has been reformatted by Knovel to provide easier navigation 6.18 International Country Code Designations 829
6.19 International Currency Codes 836
7 Bibliography 839
7.1 Specific References 839
7.2 References about the Metric System and the SI 841
7.3 References of General Interest 842
7.4 Historical References 843
7.5 International and National Standards 845
Trang 19List of Tables
Table 2.1 Chronology of definitions of the metre since 1795 5 Table 2.2 Adoption and compulsory implementation dates for the metric
system 7 Table 2.3 Timetable of the major decisions of the CGPM 9 Table 2.4 The seven SI base units 10 Table 2.5 The two supplementary SI units 12 Table 2.6 Comparison of dimension equation for several quantities in
photometry with and without symbol of solid angle 12 Table 2.7 SI derived units with special names and symbols 13 Table 2.8 Commonly used non-SI units 15 Table 2.9 Commonly used legal non-SI units defined by experiment 15 Table 2.10 Temporarily-maintained non-SI units 16 Table 2.11 Non-SI units to be discontinued 16 Table 2.12 The twenty SI prefixes 17 Table 2.13 Non-SI discontinued metric prefixes 17 Table 2.14 Prefixes for computer science units 18 Table 2.15 New binary prefixes for powers of two 18 Table 3.1 Exact conversion factors between SI and cgs practical, emu,
and esu electrical and magnetic units 23 Table 3.2 Organization of Gaussian units 22 Table 3.3 Equivalence between SI and cgs electromagnetic quantities 25 Table 3.4 Basic IEUS units 25 Table 3.5 Base and derived units of the a.u system 27 Table 3.6 UK linear measures 30 Table 3.7 UK nautical measures of length 29 Table 3.8 UK surveyors' measures of length 31 Table 3.9 UK measures of area 32 Table 3.10 UK surveyors' measure 32 Table 3.11 Circular units 33 Table 3.12 UK geometric measures of volume 33 Table 3.13 UK liquid measures of capacity 35 Table 3.14 UK dry measures 36 Table 3.15 UK avoirdupois weight 37 Table 3.16 UK apothecaries' weight 38 Table 3.17 UK troy weight 39 Table 3.18 US linear measure 40 Table 3.19 US nautical measure 40 Table 3.20 US surveyors' measure 41 Table 3.21 US measures of area 41 Table 3.22 US surveyors' measure 41 Table 3.23 US measures of volume 42 Table 3.24 US fluid measure 43 Table 3.25 US dry measure 44 Table 3.26 US apothecaries' measures of capacity 44 Table 3.27 US avoirdupois weight 45 Table 3.28 US apothecaries' weight 45 Table 3.29 US troy weight 45 Table 3.30 UK units of weight for butter and cheese 46
Trang 20Table 3.31 UK units for alcohols and spirits 46 Table 3.32 UK units of capacity for beer 47 Table 3.33 UK units of capacity for wine 47 Table 3.34 UK units of weight for coal 48 Table 3.35 UK clothes units of length 47 Table 3.36 UK and US hay and straw weights 49 Table 3.37 UK weight for wool 49 Table 3.38 US units of capacity used in food recipes 50 Table 3.39 US units of capacity for wine 49 Table 3.40 Modern UK and US dimensionless units for numbers of
paper sheets 51 Table 3.41 Old UK and US dimensionless units for numbers of
paper sheets 51 Table 3.42 US units of volume for stacked firewood 52 Table 3.43 UK and US dimensionless counting units 53 Table 3.44 FPS derived units in common use 55 Table 3.45 Old Chinese units of length 58 Table 3.46 Old Chinese units of area 57 Table 3.47 Old Chinese units of weight 57 Table 3.48 Old Chinese units of capacity 59 Table 3.49 Indian units of length 61 Table 3.50 Indian units of weight 60 Table 3.51 Indian units of capacity (measured by weight) 62 Table 3.52 Egyptian units of length (System of the Pharaon) 63 Table 3.53 Egyptian units of area 61 Table 3.54 Egyptian units of weight 65 Table 3.55 Egyptian units of capacity (measured by weight) 65 Table 3.56 Persian units of length 66 Table 3.57 Persian units of area 65 Table 3.58 Persian units of weight 67
Table 3.59 Persian units of capacity (measured by weight) 67
Table 3.60 Hebrew units of length 67 Table 3.61 Hebrew units of weight (sacred system) 67 Table 3.62 Hebrew units of weight (Talmudic or Rabbinical system) 68 Table 3.63 Hebrew units of capacity (measured by weight) (Dry products) 68 Table 3.64 Hebrew units of capacity (measured by weight) (Liquids) 68 Table 3.65 Greek (Attic) units of length 69 Table 3.66 Greek (Attic) units of weight 70 Table 3.67 Greek (Attic) units of capacity (Dry products) 70 Table 3.68 Greek (Attic) units of capacity (Liquids) 70 Table 3.69 Roman units of length 71 Table 3.70 Roman units of area 72 Table 3.71 Roman units of weight 74 Table 3.72 Roman units of capacity (Dry materials) 73 Table 3.73 Roman units of capacity (Liquids) 75 Table 3.74 Arabic units of length 76 Table 3.75 Arabic units of area 77 Table 3.76 Arabic units of weight 77 Table 3.77 Arabic units of capacity (measured by weight) 78 Table 3.78 Old French units of length 79 Table 3.79 Old French nautical units of length 79 Table 3.80 Old French units of area 79 Table 3.81 Old French units of area (regional variations) 80 Table 3.82 Old French units of capacity (Liquids) 81 Table 3.83 Old French units of capacity (Dry materials) 80 Table 3.84 Old French units of weight 82 Table 3.85 Old French units of weight (Charlemagne) 82
Trang 21Table 3.86 Old French units of length (metric) 83 Table 3.87 Old French units of weight (metric) 83 Table 3.88 Old Belgian units of length 83 Table 3.89 Old Belgian units of weight 84 Table 3.90 Old Swiss units of length 84 Table 3.91 Old Swiss units of weight (Ordinary) 84 Table 3.92 Old Swiss units of weight (Apothecary) 84 Table 3.93 Old Scottish units of length 85 Table 3.94 Old Scottish units of area 85 Table 3.95 Old Scottish units of capacity (Liquids) 85 Table 3.96 Old Scottish units of capacity (Dry) 86 Table 3.97 Old Scottish units of weight 86 Table 3.98 Old Irish units of length 86 Table 3.99 Old Irish units of capacity (Liquids) 87 Table 3.100 Old Italian units of length 87 Table 3.101 Old Italian units of weight 87 Table 3.102 Old Italian measures (regional variations) 88 Table 3.103 Old Spanish units of length 89 Table 3.104 Old Spanish units of area 88 Table 3.105 Old Spanish units of weight 91 Table 3.106 Old Spanish units of capacity (Liquids) 92 Table 3.107 Old Spanish units of capacity (Dry) 90 Table 3.108 Old Portuguese units of length 92 Table 3.109 Old Portuguese units of area 90 Table 3.110 Old Portuguese units of weight 93 Table 3.111 Old Portuguese units of capacity (Dry) 93 Table 3.112 Old Portuguese units of capacity (Liquids) 93 Table 3.113 Old Maltese units of length 94 Table 3.114 Old Maltese units of capacity (Liquids) 94 Table 3.115 Old Maltese units of weight 94 Table 3.116 Old Balearic units of length 94 Table 3.117 Old Balearic units of capacity (Liquids) 94 Table 3.118 Old Balearic units of capacity (Dry) 95 Table 3.119 Old Balearic units of weight 95 Table 3.120 Old Greek units of length 95 Table 3.121 Old Greek units of capacity (Liquids) 95 Table 3.122 Old Greek units of weight 96 Table 3.123 Old Cypriot units of length and area 96 Table 3.124 Old Cypriot units of capacity 96 Table 3.125 Old Cypriot units of weight 96 Table 3.126 Old Turkish units of length 97 Table 3.127 Old Turkish units of area 97 Table 3.128 Old Turkish units of capacity 97 Table 3.129 Old Turkish units of weight 98 Table 3.130 Old Austrian units of length 99 Table 3.131 Old Austrian units of area 99 Table 3.132 Old Austrian units of capacity (Liquids) 99 Table 3.133 Old Austrian units of capacity (Dry) 100 Table 3.134 Old Austrian units of weight (Ordinary) 101 Table 3.135 Old Austrian units of weight (Apothecary) 100 Table 3.136 Old German units of length 100 Table 3.137 Old German units of weight 102 Table 3.138 Old German units of capacity (Dry) 103 Table 3.139 Old German units of capacity (Liquids) 103 Table 3.140 Old Yugoslavian units of length 103 Table 3.141 Old Yugoslavian units of area 103 Table 3.142 Old Yugoslavian units of weight 104
Trang 22Table 3.143 Old Czechoslovakian units of length
(Bohemia, Silesia, Moravia, and Praha) 104 Table 3.144 Old Czechoslovakian units of area 104 Table 3.145 Old Czechoslovakian units of capacity 104 Table 3.146 Old Hungarian units of length 105 Table 3.147 Old Hungarian units of area 105 Table 3.148 Old Hungarian units of capacity 105 Table 3.149 Old Romanian units of length 105 Table 3.150 Old Romanian units of capacity (Liquids) 105 Table 3.151 Old Romanian units of capacity (Dry) 106 Table 3.152 Old Romanian units of weight 106 Table 3.153 Old Dutch units of length 106 Table 3.154 Old Dutch units of weight 106 Table 3.155 Old Dutch units of capacity (Dry) 107 Table 3.156 Old Dutch units of capacity (Liquids) 108 Table 3.157 Old Danish units of length 107 Table 3.158 Old Danish units of area 107 Table 3.159 Old Danish units of capacity (Liquids) 110 Table 3.160 Old Danish units of capacity (Dry) 109 Table 3.161 Old Danish units of weight I l l Table 3.162 Old Polish units of length 109 Table 3.163 Old Polish units of area 109 Table 3.164 Old Polish units of capacity 112 Table 3.165 Old Polish units of weight 112 Table 3.166 Old Swedish units of length (decree of 1665) 113 Table 3.167 Old Swedish units of area (decree of 1665) 113 Table 3.168 Old Swedish units of weight (decree of 1665) 114 Table 3.169 Old Swedish units of capacity (Dry) 115 Table 3.170 Old Swedish units of capacity (Liquids) 116 Table 3.171 Miscellaneous old Norwegian units 116 Table 3.172 Old Finnish units of capacity 116 Table 3.173 Old Icelandic units of length 117 Table 3.174 Old Icelandic units of area 118 Table 3.175 Old Icelandic units of capacity (Dry) 118 Table 3.176 Old Icelandic units of weight 117 Table 3.177 Old Estonian units of length 117 Table 3.178 Old Estonian units of area 119 Table 3.179 Old Estonian units of capacity 119 Table 3.180 Old Estonian units of weight 119 Table 3.181 Old Latvian units of length 119 Table 3.182 Old Latvian units of area 120 Table 3.183 Old Latvian units of capacity 120 Table 3.184 Old Latvian units of weight 120 Table 3.185 Old Russian units of length 121 Table 3.186 Old Russian units of weight (Ordinary) 122 Table 3.187 Old Russian units of weight (Apothecary) 122 Table 3.188 Old Russian units of capacity (Dry) 123 Table 3.189 Old Russian units of capacity (Liquids) 124 Table 3.190 Old Moroccan units of length 122 Table 3.191 Old Moroccan units of capacity 125 Table 3.192 Old Moroccan units of weight 125 Table 3.193 Old Algerian units of length 125 Table 3.194 Old Algerian units of capacity 125 Table 3.195 Old Algerian units of weight 126 Table 3.196 Old Tunisian units of length 126 Table 3.197 Old Tunisian units of capacity 126 Table 3.198 Old Tunisian units of weight 126
Trang 23Table 3.199 Old Libyan units of length 127 Table 3.200 Old Libyan units of area 127 Table 3.201 Old Libyan units of capacity (Liquids) 127 Table 3.202 Old Libyan units of capacity (Dry) 127 Table 3.203 Old Libyan units of weight 128 Table 3.204 Old Egyptian units of length 128 Table 3.205 Old Egyptian units of area 128 Table 3.206 Old Egyptian units of capacity 129 Table 3.207 Old Egyptian units of weight 130 Table 3.208 Old Abyssinian units of length 130 Table 3.209 Old Abyssinian units of capacity 130 Table 3.210 Old Abyssinian units of weight 130 Table 3.211 Old Eritrean units of length 131 Table 3.212 Old Eritrean units of capacity 131 Table 3.213 Old Eritrean units of weight 131 Table 3.214 Old Ethiopian units of length 131 Table 3.215 Old Ethiopian units of weight 133 Table 3.216 Old Somalian units of length 132 Table 3.217 Old Somalian units of capacity 132 Table 3.218 Old Somalian units of weight 132 Table 3.219 Old Guinean units of length 132 Table 3.220 Old Guinean units of weight 134 Table 3.221 Old Saudi-Arabian units of length 135 Table 3.222 Old Saudi-Arabian units of capacity (Liquids) 135 Table 3.223 Old Saudi-Arabian units of capacity (Dry) 135 Table 3.224 Old Saudi-Arabian units of weight 136 Table 3.225 Old Persian units of length 136 Table 3.226 Old Persian units of capacity 136 Table 3.227 Old Persian units of weight 137 Table 3.228 Old Syrian units of length 138 Table 3.229 Old Syrian units of capacity 138 Table 3.230 Old Syrian units of weight 138 Table 3.231 Old Turkmenian units of length 138 Table 3.232 Old Turkmenian units of weight 138 Table 3.233 Old Indian units of length 140 Table 3.234 Old Indian units of area 139 Table 3.235 Old Indian units of capacity 141 Table 3.236 Old Indian units of weight 142 Table 3.237 Old Burmese units of length 139 Table 3.238 Old Burmese units of capacity 143 Table 3.239 Old Burmese units of weight 143 Table 3.240 Old Ceylonese and Madrasian units of length 143 Table 3.241 Old Ceylonese and Madrasian units of weight 143 Table 3.242 Old Annamese units of length 144 Table 3.243 Old Annamese units of area 144 Table 3.244 Old Annamese units of capacity 144 Table 3.245 Old Annamese units of weight 145 Table 3.246 Old Cambodian units of length 146 Table 3.247 Old Cambodian units of capacity 146 Table 3.248 Old Cambodian units of weight 147 Table 3.249 Old Thai units of length 148 Table 3.250 Old Thai units of area 146 Table 3.251 Old Thai units of capacity 149 Table 3.252 Old Thai units of weight 150 Table 3.253 Old Indonesian units of length 151 Table 3.254 Old Indonesian units of capacity 151 Table 3.255 Old Indonesian units of weight 152
Trang 24Table 3.256 Old Philippine units of area 151 Table 3.257 Old Philippine units of capacity 151 Table 3.258 Old Philippine units of weight 153 Table 3.259 Old Japanese units of length 154 Table 3.260 Old Japanese units of area (land measures) 153 Table 3.261 Old Japanese units of capacity 153 Table 3.262 Old Japanese units of weight 155 Table 3.263 Old Cuban units of area 156 Table 3.264 Old Cuban units of capacity 156 Table 3.265 Old Haitian units of length 156 Table 3.266 Old Haitian units of capacity 156 Table 3.267 Old Honduran, Costa-Rican, Nicaraguan, Salvadoran,
and Guatemalan units of length 157 Table 3.268 Old Honduran, Costa-Rican, Nicaraguan, Salvadoran,
and Guatemalan units of area 157 Table 3.269 Old Honduran, Costa-Rican, Nicaraguan, Salvadoran,
and Guatemalan units of capacity 157 Table 3.270 Old Honduran, Costa-Rican, Nicaraguan, Salvadoran,
and Guatemalan units of weight 158 Table 3.271 Old Venezuelan units of length 158 Table 3.272 Old Venezuelan units of weight 158 Table 3.273 Old Colombian units of length 159 Table 3.274 Old Colombian units of weight 159 Table 3.275 Old Brazilian units of length 159 Table 3.276 Old Brazilian units of capacity 160 Table 3.277 Old Brazilian units of weight 160 Table 3.278 Old Paraguayan units of length 160 Table 3.279 Old Paraguayan units of capacity 161 Table 3.280 Old Paraguayan units of weight 161 Table 3.281 Old Argentinan units of length 161 Table 3.282 Old Argentinan units of capacity (Liquids) 162 Table 3.283 Old Argentinan units of capacity (Dry) 162 Table 3.284 Old Argentinan units of weight 162 Table 3.285 Old Chilean units of length 162 Table 3.286 Old Chilean units of capacity 163 Table 3.287 Old Chilean units of weight 163 Table 3.288 Old Peruvian units of length and area 163 Table 3.289 Old Peruvian units of weight 163 Table 3.290 Old Mexican units of length 164 Table 3.291 Old Mexican units of area 164 Table 3.292 Old Mexican units of capacity (Liquids) 164 Table 3.293 Old Mexican units of capacity (Dry) 164 Table 3.294 Old Mexican units of weight 165 Table 4.1 Units in alphabetical order 171 Table 4.2.1.1 Conversion table: units of mass: multiples and submultiples (SI) 674 Table 4.2.1.2 Conversion table: units of mass (>1 kg) 676 Table 4.2.1.3 Conversion table: units of mass (<1 kg) 678 Table 4.2.1.4 Conversion table for atomic units of mass 682 Table 4.2.2.1 Conversion table: units of length, multiples and submultiples (SI) 684 Table 4.2.2.2 Conversion table: units of length (>1 m) 686 Table 4.2.2.3 Conversion table: units of length (<1 m) 690 Table 4.2.2.4 Conversion table: units of length (Typography) 694 Table 4.2.3.1 Conversion table: units of area: multiples and submultiples (SI) 695
Table 4.2.4.1 Conversion table: units of volume: multiples and submultiples (SI) 702 Table 4.2.4.2 Conversion table: units of volume (>1 L) 704
Trang 25Table 4.2.4.3 Conversion table: units of volume (<1 L) 706 Table 4.2.5 Conversion table: units of linear mass density 708 Table 4.2.6 Conversion table: units of surface mass density 709 Table 4.2.7 Conversion table: units of mass density 710 Table 4.2.8 Conversion table: hydrometer degrees 712 Table 4.2.9 Conversion table: units of time 714 Table 4.2.10 Conversion table: units of dynamic viscosity 716 Table 4.2.11 Conversion table: units of kinematic viscosity 717 Table 4.2.12 Conversion table: units of linear velocity 718 Table 4.2.13 Conversion table: units of angular velocity 720 Table 4.2.14 Conversion table: units of force and weights 722 Table 4.2.15 Conversion table: units of pressure and stress 724 Table 4.2.16 Conversion table: units of energy, heat and work 728 Table 4.2.17 Conversion table: units of power 730 Table 4.2.18 Conversion table: units of plane and solid angle 734 Table 4.2.19 Conversion table: units of thermal conductivity 736 Table 4.2.20.1 Conversion table: units of concentration 738 Table 4.2.20.2 Conversion table: equations between various quantities used
to measure concentration 739 Table 4.2.21 Conversion table: units of temperature 740 Table 4.2.22 Conversion table: units used in electricity 741 Table 4.2.23 Conversion table: units used in magnetism 742 Table 4.2.24 Conversion table: units used in photometry 743 Table 4.2.25 Conversion table: units used in nuclear sciences 744 Table 4.2.26 Conversion table: energy equivalents for
electromagnetic radiation 745 Table 4.2.27 Conversion table: ideal gas constant in various units 746 Table 4.2.28 Conversion table: dimensions for permeability coefficients
(example of non-SI units) 747 Table 4.2.29 Conversion table: international kinematic viscosity coefficients 748 Table 4.2.30 Conversion table: standard sieve designation series
(ISO, ASTM, CSA, Tyler, AFNOR, BS, and DIN) 751 Table 4.2.31 Conversion table: international standard wire and sheet gauges 755 Table 4.2.32 Conversion table: normal pipe sizes (NPS) 759 Table 5.1 Fundamental mathematical constants 771 Table 5.2 Universal constants 772 Table 5.3 Physico-chemical constants 773 Table 5.4 Electromagnetic and atomic constants 774 Table 5.5 Electron constants 775 Table 5.6 Proton constants 776 Table 5.7 Neutron constants 777 Table 5.8 Muon (+) constants 778 Table 5.9 Deuteron constants 778 Table 5.10 Helion constants (CODATA, 1998) 779 Table 5.11 Alpha particle constants (CODATA, 1998) 779 Table 6.1 The Greek alphabet 781 Table 6.2 Roman numerals 782 Table 6.3 International standards bodies 784 Table 6.4 National standards bodies worldwide 785 Table 6.5 US and international standards bodies, technical associations
and societies 800 Table 6.6 International Practical Temperature Scale of 1968 812 Table 6.7 Fixed points in the International Temperature Scale
of 1990 (ITS-90) 813 Table 6.8 French-English lexicon for units 814 Table 6.9 French-English lexicon for physical quantities 817 Table 6.10 International clothing and shoe sizes 819
Trang 26Table 6.11 Common time acronyms 822 Table 6.12 Old alchemical symbols 822 Table 6.13 International geological time scale 823 Table 6.14 Obsolete symbols for British apothecaries' units 826 Table 6.15 Electromagnetic spectrum 827 Table 6.16 ISO standard paper sizes: designation and formulae 828 Table 6.17 ISO standard paper sizes (rounded to the nearest mm) 828 Table 6.18 US paper sizes 828 Table 6.19 International country code designations
(ISO, IANA, UN, and IOC) 829 Table 6.20 International currency codes with approximate exchange rates
in US dollars 836
Trang 271.1 Why a Conversion Handbook?
Books on the conversion of scientific units into their SI equivalents are relatively rare in
scientific literature There are several specialized treatises (see Bibliography) on the subject
as applied to certain areas of science and technology, which contain sections on the subject, supported by conversion tables However, these tables are anything but exhaustive, and it
is often necessary to consult sources in several very different areas in order to obtain the desired information.
This practical manual aims to be the most comprehensive work on the subject of unit conversion It contains more than 20 000 precise conversion factors, and around 5000 definitions of the units themselves The units included, and their conversions, are grouped into imperial and US units, conventional metric units, older or out-of-date units, ancient units, and SI units The subject areas involved are: pure and applied science, technology, medicine, and economics Some examples of individual sciences covered are mechanical, electrical, chemical, and nuclear engineering, civil and mining engineering, chemistry, physics, biology, medicine, economics, and computer sciences In other words, this book places unit conversion at the disposal of everyone It saves working time, and should be available in all research libraries and design offices It has been kept as small as possible in order to facilitate consultation in all circumstances, whether in the office, on the produc- tion line, or on the move.
The aim of this book is to ensure rapid and accurate conversion of scientific units to their SI equivalents However, the reader should be aware that it does not provide rules and advice for writing the names, nor the recommended symbols for physical quantities used in
This book is suitable for researchers, scientists, engineers and technologists, economists, doctors, pharmacists, and patent lawyers, but is equally suitable for teachers and students.
Encyclopaedia of Scientific Units, Weights and Measures is the product of many years
spent collecting information spread across scientific and technical literature Each item of information has been carefully checked and verified Additionally, certain pieces of information have been extracted from books or standards for the most part published
by national and international bodies (e.g ISO, AFNOR, BSI, DIN, IEC, ANSI, NACE, NIST) Every effort has been made to supply conversion factors as precisely as possible to an accuracy of nine decimal places.
1
Mills, L, Cvitas, T., Homann, K., Kallay, N and Kuchitsu, K (eds.)> Quantities, Units and Symbols in Physical Chemistry, 2nd ed, IUPAC, Blackwell Scientific Publications, Oxford, 1993.
Trang 281.2 How to Use This Book
Chapter 2 contains a brief history of the metric system, including the organization and a
complete description of SI Units (Systeme International d'Unites).
Chapter 3 gives a detailed description of a considerable number of other systems of measurement This includes several alternative modern systems of measurement, some of which are still in widespread use (e.g imperial, US, cgs, MTS, FPS) Finally, there is a description of systems used in antiquity (e.g ancient Chinese, Indian, Egyptian, Persian, Hebrew, Greek, Roman, Arabic), as well as older national or regional systems (e.g French, Italian, German, Japanese).
Chapter 4, which forms the most important part of the book, consists of an exhaustive set of conversion tables This chapter covers the units in alphabetical order Each unit is fully described as follows: name, symbol(s), physical quantity, dimension, conversion factor, notes and definitions The section covers some 5000 units, each with a precise conversion factor.
Chapter 5 enables a unit to be identified from its area of application For this purpose, units are classed in groups It contains thirty five conversion tables ranging from mass to nuclear quantities.
In order to facilitate use of this manual, several supplementary sections have been added
to aid the researcher These include tables of fundamental mathematical and physical constants to allow very precise calculation of conversions These form the sixth chapter of the book.
Appendices contain a list of many national and international bodies in the area of standardization, rules of nomenclature for large numbers, notation for times and dates, and a brief French-English glossary of names of units and associated physical quantities Finally, a detailed bibliography (e.g national and international standards, textbooks, specialized engineering handbooks) is presented at the end of the book in order to allow the reader to go further in their investigations.
This practical manual provides rapid answers to all questions concerning the conversion
of scientific units Some examples of the sort of questions that can be answered more rapidly thanks to this manual, along with the chapters where their answers can be found, are given below:
• What is the history of SI units? (2)
• What are the base units of the SI? (2)
• What were the ancient systems of measurement? (3)
• How is the imperial system organized? (3)
• What is a kip? (4)
• Which unit has the abbreviation pcu? (4)
• What are the dimensions of the rontgen? (4)
• What is the conversion factor from spats to steradians? (4)
• What are the different kinds of units of pressure and stress? (4)
• What is the exact value of the velocity of light in vacuum? (5)
• What are the old symbols for imperial units? (6)
• What are the addresses of standards bodies in the US? (6)
• What are the ISO and AFNOR standards for quantities in nuclear physics? (7)
Trang 29The International System of Units
2.1 History
The origin of the metric system, and of its later version, the International System (Systeme International, SI) of units, goes back a long way into French history Before that, the old
French measures had presented two serious problems:
• units with the same name varied from one region to the next and had to be defined accordingly (e.g., pied de Paris)
• subdivisions were not decimal, which increased the complexity of commercial tions
transac-As early as 1670, the Abbe Gabriel Mouton proposed one thousandth of a minute of arc (or 1/1000) at the meridian as a rational standard of length This represents a length of
divided it decimally into three multiple units, named respectively centuria, decuria, and
the Abbe died before seeing his ideas adopted.
Over the years, the English mathematician and architect Sir Christopher Wren (1667), the French astronomer Abbe Jean Picard (1671), the Dutch scientist Christiaan Huygens (1673), and the French geodesist Charles Marie de Ia Condamine (1746) proposed the length of the seconds pendulum as a unit of length Finally, in 1789, there came a general call for the use of the same measures throughout France.
Soon afterwards, on March 9th, 1790, at the instigation of Charles Maurice de Talleyrand,
project for weights and measures The project was adopted on May 8th, 1790, and the Academy of Sciences was given the task of studying the matter A commission of French mathematicians was made responsible for establishing the base unit; its members were Count Louis de Lagrange, Gaspard Monge, Charles de Borda, and Marie Jean Antoine de Condorcet, plus the astronomer the Marquis Pierre Simon de Laplace On March 19th,
1791, this commission decided on a unit of length equal to one ten millionth of the distance
between the equator and the pole This unit was called the metre, from the Greek word, metron, for measure, and it is of course the origin of the name to the system itself.
In 1795, according to the text of the organic law of 18 Germinal year III (in terms of the revolutionary calendar then in force - equivalent to April 7th, 1795), the Systeme Metrique
2
Name of the French Revolutionary Assembly from July 9th, 1789 until September 30th, 1791.
Trang 30Decimal was instituted in France This decimal metric system established a new set of units,
the are (Latin area) for area, the litre (Greek litray a 12-ounce weight) for volume, and for mass the gram (Greek grammay the weight of a pea).
In 1795, Jean-Baptiste Delambre and Pierre Mechain, who had spent almost seven years measuring the geodetic distances between Rodez and Barcelona, and Rodez and Dunker- que, respectively, determined the length of the quarter meridian through Paris The law
established the length of the metre at 0.513074 toises de Paris, and prototype standards of
dense pure platinum for the metre and kilogram, made by Jeannetty from agglomerated platinum sponge, were adopted in June 1799 It is easy to imagine that the substitution of these new metric measures for the old units in use until then was not achieved without a lot
of problems and objections.
In 1812, the former units were re-established by the Emperor Napoleon However, metric units were reinstated by the Law of July 4th, 1837 which declared the Decimal Metric System obligatory in France from January 1840, and instituted penalties for the use of other weights and measures.
After that, the system slowly extended its application beyond the borders of France, and even became legal, though not compulsory, in the United States in 1866 However, the main
launching pad for its internationalization was the meeting of the Commission
Internatio-nale du Metre (International Metric Commission) in Paris on August 8th-13th, 1872 The
treaty known as the Convention du Metre (International Metric Convention) was signed on
May 20th, 1875 by an assembly of representatives of 17 countries including the USA It
established the Conference Generate des Poids et Mesures (General Conference on Weights and Measures, CGPM), and the Bureau International des Poids et Mesures (International
Bureau of Weights and Measures, BIPM) The headquarters of the International Bureau, which is maintained by all the national members, was established at the Pavilion de Breteuil, at Sevres, near Paris, in consideration of the role of France as the birthplace of the metric system The first General Conference on Weights and Measures (1st CGPM), held in 1889, organized the distribution of copies of the international standard prototype metre to the 21 member states of the International Metric Convention The copies of the
new standard prototype called metre international were built from platinum-iridium alloy
(Pt90-Irl0) which is an outcome of the work of Sainte-Claire Deville et al.3'4 The secondary standards were a typical bar with X cross-section having a side of 2 cm.
A summary of definitions of the metre is given in Table 2-L
The Systeme International d'Unites (SI) is the ultimate development of the metric
system Previous versions included the cgs (centimetre-gram-second), the MTS tonne-second), the MKS (metre-kilogram-force-second), and the MKSA (metre-kilogram- second-ampere) or Giorgi systems.
(metre-In 1954, the 10th CGPM adopted a set of base units for the following physical quantities: length, mass, time, electric current, thermodynamic temperature, and luminous intensity The 11th CGPM, in 1960, by its Resolution 2, adopted the name Systeme International d'Unites, to be known by its international abbreviation SI This system established rules for prefixes, for derived units, for supplementary units, as well as an overall control of units of measurement Since then, the SI has evolved and developed via the various CGPMs.
3 Sainte-Claire Deville, H., Broch et Stas, De Ia regie en forme de X en platine iridie pur a 10 pour cent
d'iridium Ann Chim Phys., 22 (1881) 120-144.
4
Sainte-Claire Deville, H., et Mascart, E., Ann Ecole Normale, 8 (1879) 9.
Trang 31Table 2-1 Chronology of definitions of the metre since 1795
On appellera metre Ia mesure
de longueur egale a Ia millionieme partie de Tare de meridien terrestre compris entre Ie pole boreal et Pequateur
dix-Le metre et Ie kilogramme en platine deposes Ie 4 Messidor dernier au Corps legislatif par l'lnstitut national des sciences et des arts sont les etalons definitifs des mesures
de longueur et de poids dans toute Ia Republique Les 18 Etats signataires de Ia Convention du metre sanctionnent a l'unanimite Ie Prototype du metre choisi par Ie Comite international; ce prototype representera desormais, a Ia temperature de Ia glace fondante, l'unite metrique de longueur.
L'unite de longueur Ie metre, defini par Ia distance a OC, des axes des deux traits medians traces sur Ia barre
de platine iridie deposee au BIPM1 et declaree Prototype
du metre par Ia lere CGPM, cette regie etant soumise a Ia pression atmospherique normale et supportee par deux rouleaux d'au moins un centimetre de diametre, situes symetriquement dans
un meme plan horizontal et a
Ia distance de 571 mm Tun
de Tautre [7eme CGPM (1927)]
Le metre est Ia longueur egale a 1650763.73 longueurs d'onde dans Ie vide de Ia radiation correspondante a Ia transition entre les niveaux 2p 10 et 5d 5 de l'atome de krypton 86 [lleme CGPM (I960)]
Le metre est Ia longueur du trajet parcouru dans Ie vide par Ia lumiere pendant une duree de 1/299792458 de seconde [17eme CGPM (1983), Resolution 1]
Date April 7th, 1795
June 22nd 1799
September 26th, 1889
September 30th, 1927
October 14th, 1960
October 20th, 1983
Absolute error 0.5-0.1 mm
0.05-0.01 mm
0.2-0.1 urn
n.a.
0.01-0.005 um
0.1 nm?
Relative error
Trang 32In France, the SI became mandatory in 1961 The 14th CGPM, in 1972, defined a new unit, the mole, for amount of substance, to be adopted as the seventh SI base unit Figure 2-1 charts the advance of metric usage throughout the world Table 2-2 gives the dates of adoption and compulsory implementation for individual countries.
The SI possesses several advantages First, it is both metric and decimal Second, fractions have been eliminated, multiples and submultiples being indicated by a system
of standard prefixes, thus greatly simplifying calculations Each physical quantity is expressed by one unique unit, and derived SI units are defined by simple equations relating two or more base units Some derived units have been given individual names.
In the interests of clarity, SI provides a direct relationship between mechanical, electrical, nuclear, chemical, thermodynamic, and optical units, thus forming a coherent system There is no duplication of units for the same physical quantity, and all derived units are obtained by direct one-to-one relationships between base or other derived units The same system of units can be used by researchers, engineers, or technologists.
2.2 The General Conference on Weights and Measures
The General Conference on Weights and Measures (CGPM) is an international tion made up of the delegates of all member states In October 1985, the number of member states was 47 The remit of this organization is to take all necessary measures to ensure the propagation and the development of the SI, and to adopt various international scientific resolutions relative to new and fundamental developments in metrology.
organiza-Under the authority of the CGPM, the International Committee for Weights and Measures (CIPM) is responsible for the establishment and control of units of measurement.
A permanent organization, the International Bureau of Weights and Measures (BIPM) created by the Metric Convention and signed by the 17 nations in Paris in 1875, operates
in the Saint-Cloud Park at Sevres, has the remit of ensuring unification of measurements throughout the world, specifically:
• to establish fundamental standards and scales of the main physical quantities, and to preserve international prototypes
• to carry out comparisons of national and international standards
• to ensure co-ordination of appropriate measurement techniques
• to carry out and co-ordinate determination of physical constants involved in the above activities
A timetable of the major decisions of the CGPM is given in Table 2-3.
5
Subsequent to the statutory order no 61-501 of May 3rd, 1961, which appeared in the Journal Officiel de
Ia Republique Frangaise of May 20th, 1961 (Lois et Decrets, Ministere de Plndustrie, pp 4584-4593).
6 Le Pavilion de Breteuil at Sevres is an enclave which has international status.
Trang 33Table 2-2 Adoption and compulsory implementation dates for the metric system Acores 1852 Gambia 1979 Panama 1916
Afghanistan 1926 Germany 1871 (1872) Papua-New
Albany 1951 Ghana 1972 (1975) Guinea 1970
Algeria 1843 Gibraltar 1970 Paraguay 1899
Angola 1905 (1910) Greece 1836 (1959) Netherlands 1816 Argentina 1863 (1887) Guatemala 1910 (1912) (1832)
Australia 1961 ; 1970 Guinea 1901-06 Peru 1862 (1869) Austria 1871 (1876) Guinea-Bissau 1905 Philippines 1906 Bahrein (1969) (1910) (1973-75)
Barbados 1973 Guyana 1971 Poland 1919
Belgium 1816(1820) Haiti 1920(1922) Portugal 1852(1872) Benin 1884-91 Honduras 1910 (1912) Puerto Rico 1849 Bermuda 1971 Hungary 1874 (1876) Romania 1864 (1884) Bolivia 1868(1871) Iceland 1907 Russia 1899; 1918 Botswana 1969-70 India 1920 (1956) (1927)
(1973) Indonesia 1923(1938) San-Marino 1907 Brazil 1862(1874) Iran 1933(1935-49) Saudi Arabia 1962 Brunei (1986-91) Iraq 1931; 1960 (1964)
Bulgaria 1888(1892) Ireland 1897(1968-69) Salvador 1910(1912) Burkina 1884-1907 Israel 1947 (1954) Senegal 1840
Cambodia 1914 Italy 1861 (1863) Seychelles 1880
Cameroun 1894 Ivory Coast 1884-90 Singapore 1968-70 Canada 1871 (1976) Jamaica 1973 Slovakia 1871 (1876) Cap-Vert 1891 Japan 1893; 1951 Solomon (British
Central African (1959-66) Islands) 1970
(Rep.) 1884-1907 Jordan 1953 (1954) Somalia 1950 (1972) Chile 1848 (1865) Kenya 1951; 1967-68 South Africa 1922; 1967 China 1929 (1930) Korea (South) 1949 (1974)
Colombia 1853 (1854) Korea (Dem Rep Spain 1849 (1871) Comores 1914 of) 1947 Sri Lanka 1970 (1974) Congo 1884-1907 Kuwait 1961 (1964) Sudan 1955
(1910) Lebanon 1935 Surinam 1871 (1916) Costa Rica 1881 (1912) Lesotho 1970 Swaziland 1969 (1973) Cuba 1882 (1960) Libya 1927 Sweden 1878 (1889) Cyprus 1972-74 Liechtenstein 1875 Switzerland 1868 (1877) Czech Republic 1871 (1876) Syria 1935
(1876) Luxemburg 1816 (1820) Taiwan 1954
Denmark 1907 (1912) Macao 1957 Tanzania 1967-69 Djibouti 1898 Madagascar 1897 Tchad 1884-1907 Dominican (Rep.) 1849 Madeira 1852 Thailand 1923(1936) (1942-55) Malawi 1979 Timor 1957
Dutch Antilles 1875 Malaysia 1971-72 Togo 1924
(1876) Mali 1884-1907 Tonga Islands 1975 Ecuador 1865-71 Malta 1910(1921) Trinidad and
Egypt 1939 (1951-61) Mauritania 1884-1907 Tobago 1970-71
El Salvador 1910 (1912) Mauritius 1876 (1878) Tunisia 1895
Ethiopia 1963 Mexico 1857 (1896) Turkey 1869; 1931 Fiji 1972 Monaco 1854 (1933)
Finland 1886 (1892) Morocco 1923 Uganda 1950 (1967-69) France 1795 (1840) Mozambique 1905 United Kingdom 1897 (Guadalupe 1844) (1910) (1995)
(French Namibia 1967 United States of
Guyana 1840) Nauru 1973-80 America 1866 (Martinique 1844) Nepal 1963 (1966-71) Uruguay 1862 (1894) Reunion 1839) New Zealand 1925 Venezuela 1857
(New (1969) (1912-14)
Caledonia 1862) Nicaragua 1910(1912) Vietnam 1911(1950) (Polynesia 1847) Niger 1884-1907 Yugoslavia 1873 (1883) (St-Pierre-et- Nigeria 1971-73 Zambia 1937(1970) Miquelon 1824-39) Norway 1875 (1882) Zimbabwe 1969
Gabon 1884-1907 Pakistan 1967-72
Important note: In 2002, the remaining non-metric countries are the USA, Myanmar (ex-Burma), and Sierra Leone.
Trang 34Figure 2.1 Advance of metric usage throughout the world ( © U.S Metric Association,
Central African Rep.
Mali, Malagasy Rep.
Dahomey, Mauretania
Niger, Senegal, Togo
Upper Volta, Somalia
Note: To the best of our knowledge the dates shown are accurate Information in the
graph is based upon certain indicators which gauge metric usage or upon official government policy regarding usage.
Trang 35Table 2-3 Timetable of the major decisions of the CGPM
Declaration concerning the definition of the litre as the
volume occupied by 1 kg of pure water at the temperature ofits maximum density (abroged in 1964) Declaration of the
kilogram as the unit of mass The weight was defined as a
quantity with the dimension of a force Adoption of the con
ventional value of standard acceleration due to gravity* i.e.,
Definition of the metre by the international Prototype
Definitions of photometric units: the new candle, and new
lumen Definitions of mechanical units which enter the
definitions of electrical units: joule, watt Definitions of
electric units: ampere, volt, ohm, coulomb, farad, henry, and weber (CIPM, 1946).
Replacement of the melting point of ice by the triple point of water for thermometric reference Thermodynamic scale with
a single fixed point Adoption of the joule as unit of quantity
of heat Adoption of degree Celsius to denote the degree of temperature.
Definition of the thermodynamic temperature scale by choosing the triple point of water as the fundamental fixed point Definition of the standard atmosphere: 101325 N/m2.
Adoption of six base units of the future SI: metre, kilogram, second, ampere, kelvin, and candela Definition of the unit of
time (CIPM, 1956).
New definitions of the metre, and of the second Adoption of the Systeme International d'unites with the acronym SI The litre is exactly defined as one cubic decimetre (CIPM, 1961).
Atomic standard of frequency Standardization of the curie to
exactly 3.7 x 1010 s"1 Introduction of new SI prefixes femto
and otto.
New definition for the second, the kelvin, and the candela.
Abrogation of obsolete units: micron, and new candle.
Multiples and submultiples of the unit of mass (CIPM, 1967).
Rules of application of the SI (CIPM, 1969).
Definition of the SI unit of the amount of a substance: mole, and adoption of two new SI derived units: the pascal and the Siemens, International atomic time (TAI).
Recommended values for the velocity of light in vacuum, and new names and units for ionizing radiation quantities:
becquerel; gray, and two new SI prefixes peta and exa.
Universal coordinated time (UTC).
New definition of the candela Special name for the SI derived unit of the dose equivalent: sievert The symbol L for litre in
addition to the lower case letter 1 Introduction of two
supplementary units: radian and steradian (CIPM, 1980).
New definition of the metre as unit of length based on the
velocity of light in vacuum New SI prefixes: zetta, zepto, yotta, and yocto (CIPM, 1990).
Abrogation of the two supplementary units Hence radian and steradian are now considered as SI derived units with special names.
Adoption of a new SI derived unit of enzymatic activity: the katal.
Next Page
Trang 362.3 Organization of the SI
The International System of Units (Systeme International dVnitesy SI) consists of three
classes of units:
• seven base units
• two supplementary units
• a number of derived units
In total, they form a coherent system of units officially known as SI units Those unitswhich do not form part of this system are known as out-of-system units
It is recommended that only SI units should be used in scientific and technologicalapplications, with SI prefixes where appropriate The use of some out-of-system units (e.g.nautical mile, hectare, litre, hour, ampere-hour, bar) remains legal and they are tempora-rily retained because of their importance or their usefulness in certain specialized fields.Nevertheless, they should always be defined in terms of SI units, and SI units should beused wherever possible in order to maintain coherence in calculations
2.3.1 SI Base Units
The seven SI base units are listed in Table 2-4 below:
Table 2-4 The seven SI base units
Physical quantity Dimension Name Symbol
Mass M kilogram kg
Length L metre m
Time T second s
Temperature 0 kelvin K
Amount of substance N mole mol
Electric current intensity I ampere A
Luminous intensity J candela cd
These seven SI base units are officially and bilingually (French-English) defined asfollows:
metre Le metre est Ia longueur du trajet parcouru dans Ie vide par Ia lumiere
pendant une duree de 1/299792 458 s [17*rae CGPM (1983),Resolution I]
The metre is the length of the path travelled by light in vacuum during atime interval of 1/299792458 s [17th CGPM (1983), Resolution I]
kilogramme Le kilogramme est l'unite de masse; il est egal a Ia masse du prototype
international du kilogramme [l*re CGPM (1889), 3*me CGPM (1901)].The kilogram is the unit of mass; it is equal to the mass of theinternational prototype of the kilogram [1st CGPM (1889), 3rd CGPM(1901)]
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Trang 37seconde La seconde est Ia duree de 9 192631 770 periodes de Ia radiation
corre-spondant a Ia transition entre les deux niveaux hyperfins (F = 4, nip = 0
a F = 3, mF = 0) de Tetat fondamental de Tatome de cesium 133 [13*mcCGPM (1967)].
The second is the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels (F = 4,
mF = 0 to F = 3, mF = 0) of the ground state of the cesium 133 atom [13th CGPM (1967)].
ampere L'ampere est l'intensite d'un courant electrique constant qui maintenu
dans deux conducteurs paralleles, rectilignes, de longueur infinie, de section circulaire negligeable et places a une distance de 1 metre Tun de Pautre dans Ie vide, produit entre ces conducteurs une force egale a
2 x 10~7 newton par metre de longueur [9*me CGPM (1948), Resolution
2 et 7].
The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-sec- tion, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2 x 10~7 newton per metre of length [9th CGPM (1948), Resolution 2 and 7].
kelvin Le kelvin, unite de temperature thermodynamique, est Ia fraction 1/
273,16 de Ia temperature thermodynamique du point triple de Teau [13*rae CGPM (1967), Resolution 4].
The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16
of the thermodynamic temperature of the triple point of water [13th CGPM (1967), Resolution 4].
mole (i) La mole represente Ia quantite de matiere totale d'un systeme qui
contient autant d'entites elementaires que 0,012 kg de carbone 12 (ii) Lorsque Ton emploie Ia mole, les entites elementaires doivent etre specifiers et peuvent etre des atomes, des ions, des electrons, d'autres particules ou des groupements specifies de telles particules [14emeCGPM (1971), Resolution 3], Dans cette definition, il est sous-entendu que les atomes de carbone 12 sont libres, au repos et dans leur etat fondamental.
(i) The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kg of carbon 12 (ii) When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particules, or specified groups of such particles [14th CGPM (1971), Resolution 3].
In this definition, it is understood that the carbon 12 atoms are unbound, at rest and in their ground state.
Trang 38candela La candela est l'intensite lumineuse, dans une direction donnee, d'une
source qui emet un rayonnement monochromatique de frequence
The candela is the luminous intensity, in a given direction, of a source
that has a radiant intensity in that direction of 1/683 watt per steradian [16th CGPM (1979), Resolution 3].
2.3.2 SI Supplementary Units
In addition to the seven base units, the SI has two supplementary units, the radian for
plane angle and the steradian for solid angle (see Table 2-5) These two units are
dimensionless (i.e in a dimension equation they have the value unity) However, forclarity, they are sometimes included in dimensional equations using an arbitrary dimen-
sional symbol, for example the Greek letter a or a Roman capital 1A* for plane angle, andthe Greek capital Q for solid angle Equally, because of the non-official nature of thisnotation, it is possible to omit these symbols from a dimensional equation in cases wherethis does not cause ambiguity
As an example, the expression for angular velocity could be equally well be written aseither [oc.T"1] or [T"1]
However, for physical quantities in specialist areas such as particle transfer in stastisticalphysics or luminous transfer in photometry, it is usual to include solid angle in dimen-sional equations in order to avoid confusion
Example: depending on whether the area of photometric work involves measurement ofenergy, visible light, or particle emissions, luminous intensity can be defined in three ways
(see Table 2-6) It is clear that confusion can be avoided by introduction of a symbol for the
steradian in the dimensional equation
Note: since Resolution 8 from the 20th CGPM (Oct 1995) the radian and the steradianare defined as common dimensionless SI derived units
Table 2-5 The two supplementary SI units
Physical quantity Dimension Name Symbol
Plane angle a radian rad
Solid angle Cl steradian sr
Table 2-6 Comparison of dimension equation for several quantities in photometry with and without symbol of solid angle
Photometry Quantity Dimensions SI unit
without symbol with symbol
Visible Luminous intensity [J] [J] c d
Trang 392.3.3 SI Derived Units
The SI derived units are defined by simple equations relating two or more base units The names and symbols of some derived units may be substituted by special names and symbols The twenty (since the adoption of the katal) derived units with special names and
symbols are listed in Table 2-7 These derived units may themselves by used in
combina-tion to form further derived units.
Table 2-7 SI derived units with special names and symbols
H Hz J kt Im Ix NaPa Po
S Sv T V
W Wb
Physical quantity radioactivity quantity of electricity, electric charge electric capacitance absorbed dose of radiation, kerma, specific energy imparted electric inductance frequency energy, work, heat enzymatic activity luminous flux illuminance force, weight electric resistance pressure, stress absolute viscosity, dynamic viscosity electric conductance dose equivalent, dose equivalent index induction field, magnetic flux density electric potential, electromotive force, potential difference power, radiant flux induction magnetic flux
Dimension
IT M- 1 L- 2 T 4 I 2
L 2 T- 2
ML 2 T- 2 I" 2
ML 2 T" 2 NT" 1
JOL" 2 MLT" 2
ML 2 T- 3 I" 2 ML- 1 T" 2 ML- 1 T" 1
Trang 40Figure 2.2 Relationships of the SI derived units with special names and the SI base units (© NIST)
SOLID LINES INDICATE MULTIPLICATION BROKEN LINES INDICATE DIVISION
SI BASE UNITS SI DERIVED UNITS WITH SPECIAL NAMES
FREQUENCY ACTIVITY
(OFARADIO NUCUDE)
POWER, HEATFLOWRATE CAPACITANCE
ELECTRIC CHARGE
coulomb farad ACCELERATION
DENSITY CELSIUS
TEMPERATURE
steradian radian
2.3.4 Non-SI and SI Units Used in Combination
For consistency and clarity, it is a general rule of SI that the use of non-SI units should be discontinued However, there are some important instances where this is either impractic- able or inadvisable The SI therefore recognizes four categories of out-of-system units which may be used in combination with SI.
2.3.4.1 Commonly Used Legal Non-SI Units
The CIPM (1969) recognized that users of SI would wish to employ certain units that are important and widely used, but which do not properly fall within the SI The special names
and symbols for these units, and their definitions in terms of SI units, are listed in Table
2-8.
2.3.4.2 Non-SI Units Defined by Experiment
This class incorporates units accepted for use, the values of which are obtained by
experiment; they are listed in Table 2-9 opposite These are important units widely used
for special problems, and were accepted by the CIPM (1969) for continuing use in parallel with SI units.