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40 CFR §1065.1005

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The procedures in this part generally follow the International System of Units (SI), as detailed in NIST Special Publication 811, which we incorporate by reference in § 1065.1010. See § 1065.20 for specific provisions related to these conventions. This section summarizes the way we use symbols, units of measure, and other abbreviations.
  1. (a)Symbols for quantities. This part uses the following symbols and units of measure for various quantities:
  2. (b)Symbols for chemical species. This part uses the following symbols for chemical species and exhaust constituents:
  3. (c)Prefixes. This part uses the following prefixes for units and unit symbols:
  4. (d)Superscripts. This part uses the following superscripts for modifying quantity symbols:
  5. (e)Subscripts. This part uses the following subscripts for modifying quantity symbols:
  6. (f)Constants.
    1. (1)This part uses the following constants for the composition of dry air:
    2. (2)This part uses the following molar masses or effective molar masses of chemical species:
    3. (3)This part uses the following molar gas constant for ideal gases:
    4. (4)This part uses the following ratios of specific heats for dilution air and diluted exhaust:
  7. (g)Other acronyms and abbreviations. This part uses the following additional abbreviations and acronyms: