§1066.1005. Symbols, abbreviations, acronyms, and units of measure.
40 C.F.R. § 1066.1005
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.
Symbols for quantities. This part uses the following symbols and units of measure for various quantities:
Symbols for chemical species. This part uses the following symbols for chemical species and exhaust constituents:
Superscripts. This part uses the following superscripts for modifying quantity symbols:
Subscripts. This part uses the following subscripts for modifying quantity symbols:
Subscripts. This part uses the following subscripts to define a quantity:
Other acronyms and abbreviations. This part uses the following additional abbreviations and acronyms:
Densities of chemical species— . This part uses the following densities of chemical species:
Constants.
This part uses the following constants for the composition of dry air—
This part uses the following molar masses or effective molar masses of chemical species—
This part uses the following molar gas constant for ideal gases—
Prefixes. This part uses the following prefixes to define a quantity:
Notes, amendments, and revision history
Amendments
[79 FR 23823, Apr. 28, 2014, as amended at 80 FR 9124, Feb. 19, 2015; 81 FR 74215, Oct. 25, 2016; 86 FR 34585, June 29, 2021; 87 FR 64866, Oct. 26, 2022; 88 FR 4710, Jan. 24, 2023]
Authority
Authority: 42 U.S.C. 7401-7671q.
Source
Source: 79 FR 23823, Apr. 28, 2014, unless otherwise noted.
Amendments
[79 FR 23823, Apr. 28, 2014, as amended at 80 FR 9124, Feb. 19, 2015; 81 FR 74215, Oct. 25, 2016; 86 FR 34585, June 29, 2021; 87 FR 64866, Oct. 26, 2022; 88 FR 4710, Jan. 24, 2023]