Abbreviations for scientific and engineering terms

A Subcommittee on Abbreviations of the Sectional Committee on Scientific and Engineering Symbols and Abbreviations has been working on the development of American Standards for abbreviations for scientific and engineering terms. The work of the subcommittee has now reached the point where it is possible to print their report as the proposed Tentative American Standard. The American Society of Mechanical Engineers, one of the joint sponsors with the Institute and three other groups, has issued the report in page proof form for the purpose of criticism and comment. Abbreviations of electrical terms form a part of the report. Probably the most notable feature of the proposed abbreviations is the omission of period except where the abbreviation forms a complete word, as (arm. for armature). The Sectional Committee has made
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the following distinction between symbols and abbreviations: A symbol is a letter or sign used in a formula as a substitute for any numerical value. A shortened expression for a name or a unit is an abbreviation and not a symbol.