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APPENDIX A. METRIC (SI) SYSTEM
A.6 Use of SI Units in Technical Writing
Several style guidelines should be followed when using SI units, symbols,
and prefixes.
1. Use lowercase letters for SI unit symbols unless the unit is
derived from a proper name (Newton, Hertz, etc.).
2. When the unit name is spelled out in unabbreviated form,
it is not capitalized. This is true for all cases (e.g., newtons,
hertz).
3. The SI symbols for all prefixes in Table A.3, with the exception of M for mega-, are written in lowercase letters.
4. SI symbols are always written in singular form (e.g., 14.2
kg). When spelling out units, form plurals in the usual
manner (e.g., 14.2 kilograms).
5. Periods are used in SI symbols only at the end of sentences.
6. No space or hyphen is used between the prefix and the SI
unit name (e.g., kilometer, millimeter).
7. A space is left between the numerical value and the unit
(e.g., 0.26 kPa).
8. Multiplication of units is given by a raised dot (e.g., N m),
and division by a diagonal line or by a negative power (e.g.,
N/m or N-m-1).
9. In writing numbers having four or more digits, the digits
should be placed in groups of three separated by a space
and formed by counting both to the left and the right of the
decimal point. In the case of exactly four digits the spacing
is optional (e.g., 12 345.678; 1234 or 1 234; 0.123 456).
A.7 Metric (SI) Conversion Factors
Table A.4 contains conversion factors which are to be used when converting numerical values expressed in English units to their equivalent values
expressed in metric (SI) units. The information contained in Table A.4 has
been condensed from the references and includes only those conversions
most likely to occur in coastal engineering.
The conversion factors have been given to an accuracy of six significant
digits, except in cases when an exact value can be given. To find the
metric equivalent of an English value, simply multiply the English value by
APPENDIX A. METRIC (SI) SYSTEM
A.6 Use of SI Units in Technical Writing
Several style guidelines should be followed when using SI units, symbols,
and prefixes.
1. Use lowercase letters for SI unit symbols unless the unit is
derived from a proper name (Newton, Hertz, etc.).
2. When the unit name is spelled out in unabbreviated form,
it is not capitalized. This is true for all cases (e.g., newtons,
hertz).
3. The SI symbols for all prefixes in Table A.3, with the exception of M for mega-, are written in lowercase letters.
4. SI symbols are always written in singular form (e.g., 14.2
kg). When spelling out units, form plurals in the usual
manner (e.g., 14.2 kilograms).
5. Periods are used in SI symbols only at the end of sentences.
6. No space or hyphen is used between the prefix and the SI
unit name (e.g., kilometer, millimeter).
7. A space is left between the numerical value and the unit
(e.g., 0.26 kPa).
8. Multiplication of units is given by a raised dot (e.g., N m),
and division by a diagonal line or by a negative power (e.g.,
N/m or N-m-1).
9. In writing numbers having four or more digits, the digits
should be placed in groups of three separated by a space
and formed by counting both to the left and the right of the
decimal point. In the case of exactly four digits the spacing
is optional (e.g., 12 345.678; 1234 or 1 234; 0.123 456).
A.7 Metric (SI) Conversion Factors
Table A.4 contains conversion factors which are to be used when converting numerical values expressed in English units to their equivalent values
expressed in metric (SI) units. The information contained in Table A.4 has
been condensed from the references and includes only those conversions
most likely to occur in coastal engineering.
The conversion factors have been given to an accuracy of six significant
digits, except in cases when an exact value can be given. To find the
metric equivalent of an English value, simply multiply the English value by