subpart_subject: "Definitions and Other Reference Material"
section_number: "1066.1005"
section_subject: "Symbols, abbreviations, acronyms, and units of measure."
cfr_reference: "40 CFR 1066.1005"
title_name: "Title 40"
title_subject: "Protection of Environment"
parts_covered: "Part 1060 to End"
revised_date: "Revised as of July 1, 2019"
publication_date: "As of July 1, 2019"
contains_description: "Containing a codification of documents of general applicability and future effect"
publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"
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The procedures in this part generally follow either the International System of Units (SI) or the United States customary units, as detailed in NIST Special Publication 811, which we incorporate by reference in § 1066.1010. See 40 CFR 1065.20 for specific provisions related to these conventions. This section summarizes the way we use symbols, units of measure, and other abbreviations.
(a)Symbols for quantities. This part uses the following symbols and units of measure for various quantities:
(b)Symbols for chemical species. This part uses the following symbols for chemical species and exhaust constituents:
(c)Superscripts. This part uses the following superscripts to define a quantity:
(d)Subscripts. This part uses the following subscripts to define a quantity:
(e)Other acronyms and abbreviations. This part uses the following additional abbreviations and acronyms:
(f)This part uses the following densities of chemical species:
(g)Constants. (1) This part uses the following constants for the composition of dry air:
(2)This part uses the following molar masses or effective molar masses of chemical species:
(3)This part uses the following molar gas constant for ideal gases:
(h)Prefixes. This part uses the following prefixes to define a quantity: