Term: flow rate https://doi.org/10.1351/goldbook.F02440 Definition: The volume rate of one component, X (e.g. air, O2 ), of the unburnt gas mixture (such as C2H2, O2, etc.) in the burner tip. Ambient temperature and pressure must be stated. Related Terms: 1) volume rate (http://doi.org/10.1351/goldbook.CT01101). Source: PAC, 1986, 58, 1737. 'Quantities and units in clinical chemistry: Nebulizer and flame properties in flame emission and absorption spectrometry (Recommendations 1986)' on page 1742 (https://doi.org/10.1351/pac198658121737) Citation: 'flow rate' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.F02440 License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.