IEEE 280:1985 pdf download.IEEE Standard Letter Symbols for Quantities Used in Electrical Science and Electrical Engineering.
IEEE 280 covers letter symbols used to represent physical quantities in the field of electrical science and electrical engineering. These symbols are independent of the units (see ANSI/IEEE Sid 260-1978 j2]) employed or special values assigned. Also included are selected symbols for mathematics and for physical constants.
2. References
When the following American National Standards referred to in this standard are superseded by a revision approved by the American National Standards Institute, the latest vision shall be used.
all ANSI YlO.17-196l (R1973). American National Standard Guide for Selecting Greek Letters Used as Letter Symbols ft)r Engineering Mathematics.
[2] ANSI/IEEE Std 260-1978. IEEE Standard Letter Symbols for Units of Measurement.
[31 ANSI/IEEE Std 268-1982, American National Standard Metric Practice.
3. General Principles of Letter Symbol Standardization
3.1 Letter Symbols
Letter symbols2 include symbols for physical quantities (quani liv symbols) and symbols for the units in which these quantities are measured (unit symbols).
A quantity symbol is, in general, a single letter3 (for example, I for electric current) specified as to general form of type, and modified when appropriate by one or more subscripts or superscripts. In a given work the same letter symbol
1The numbers in brackets correspond to those of the references in Section 2..
2Leuer symbol as a technical term does not have the same meaning as either name or abbreviation. An abbreviation is a letter or a combination of letters (plus sometimes an apostrophe or a full stop) which by convention represents a word or a name in a particular language: hence an abbreviation may be different in a different language. A symbol represents a quantity or a unit and is, therefore, independent of language.
EXAMPLE: For electromotive force, the symbol is F. whereas the abbreviation is emf in English, fern in French, and EMK in German. The word ampere is sometimes abbreviated amp: the symbol for this unit is A.
should appear throughout for the same physical quantity, regardless of the units employed or of special values assigned.
A unit symbol4 is a letter or group of letters (for example, mm for millimeter), or in a few cases a special sign. that may be used in place of the name of a unit.
3.2 Alphabets and Typography
Letter symbols are mainly restricted to the English and Greek alphabets.5 The type families that are used for text in modern book and journal publishing all include italic (sloping) type faces and related roman (upright) type faces. The former are used for quantity symbols, and the latter, for unit symbols—the distinctions are discussed more fully in the following paragraphs. (In the context of this standard, the term ivinwi is used simply to mean upright in contrast with sloping and carries no connotation regarding serifs, line widths, or the like.) In situations where roman and italic are not both available, care shall be taken to avoid confusion between quantities and units. For example, an underline is frequently used to indicate italic type, and where an underline can be provided, as in manual typewriting, this practice is often helpful.IEEE 280 pdf download.