Guide for the Use of the International System of Units (SI)

Guide for the Use of the International System of Units (SI) 
 
ix 
9 Rules and Style Conventions for Spelling Unit Names ..................................................................... 31 
 9.1 
 
Capitalization...................................................................................................................... 31 
 9.2 
 
Plurals 
.............................................................................................................................. 31 
9.3 Spelling unit names with prefixes ...................................................................................... 31 
9.4 Spelling unit names obtained by multiplication ................................................................. 31 
9.5 Spelling unit names obtained by division ........................................................................... 32 
9.6 Spelling unit names raised to powers ................................................................................ 32 
9.7 Other spelling conventions ................................................................................................ 32 
9.8 Unacceptability of applying mathematical operations to unit names ................................ 32 
10 More on Printing and Using Symbols and Numbers in Scientific and Technical Documents ........ 32 
 10.1 
 
Kinds 
of symbols ............................................................................................................... 33 
10.1.1 
 
Standardized 
quantity symbols ............................................................................ 33 
10.1.2 Standardized mathematical signs and symbols .................................................... 33 
 10.2 
 
Typefaces for symbols........................................................................................................ 33 
10.2.1 
 
Quantities 
and 
variables—italic .......................................................................... 34 
10.2.2 Units— roman ..................................................................................................... 35 
10.2.3 
 
Descriptive terms—roman ................................................................................... 35 
10.2.4 
 
Sample 
equations 
showing correct type .............................................................. 35 
10.3 Greek alphabet in roman and italic type ............................................................................. 35 
 10.4 
 
Symbols 
for the elements .................................................................................................. 36 
10.4.1 Typeface and punctuation for element symbols ................................................... 36 
10.4.2 Subscripts and superscripts on element symbols.................................................. 36 
 10.5 
 
Printing numbers ................................................................................................................ 37 
10.5.1 
 
Typeface 
for numbers .......................................................................................... 37 
10.5.2 
 
Decimal 
sign or marker ....................................................................................... 37 
10.5.3 
 
Grouping digits..................................................................................................... 37 
10.5.4 
 
Multiplying numbers ........................................................................................... 37 
Appendix A. Definitions of the SI Base Units...................................................................................... 39 
 A.1 
 
Introduction ........................................................................................................................ 39 
 A.2 
 
Meter 
................................................................................................................................. 39 
 A.3 
 
Kilogram............................................................................................................................. 39 
 A.4 
 
Second 
............................................................................................................................... 39 
 A.5 
 
Ampere 
.............................................................................................................................. 39 
 A.6 
 
Kelvin 
 
............................................................................................................................... 39 
 A.7 
 
Mole.................................................................................................................................... 39 
 A.8 
Candela............................................................................................................................... 39 
Appendix B. Conversion Factors ......................................................................................................... 40 
 B.1 
Introduction ....................................................................................................................... 40 
 B.2 
 
Notation 
............................................................................................................................. 40 
B.3 Use of conversion factors ................................................................................................... 40 
B.4 Organization of entries and style ....................................................................................... 41 
B.5 Factor for converting motor vehicle efficiency ................................................................. 42 
B.6 U.S. survey foot and mile ................................................................................................... 42 
B.7 Rules for rounding numbers and converted numerical values of quantities ...................... 43 
B.7.1 Rounding numbers .................................................................................................. 43 
B.7.2 Rounding converted numerical values of quantities ............................................... 43 
B.8 Factors for units listed alphabetically ................................................................................. 45 
B.9 Factors for units listed by kind of quantity or field of science ........................................... 57 

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