{"term":{"id":"04270","title":"observation height","longtitle":"IUPAC Gold Book - observation height","doi":"10.1351\/goldbook.O04270","code":"O04270","status":"current","definitions":[{"id":1,"text":"The difference in height between the axis of the observed space (optical axis) and the burner tip (in \\(\\mathrm{mm}\\)). The optical axis of the instrument should be the same as the optical axis of the observation space. Other definitions which express the observation height as a fraction of the whole flame height are not recommended because the height to the tip of the flame is not well defined. The observation height should be stated in the method.","contexts":[],"sources":["PAC, 1986, 58, 1737. 'Quantities and units in clinical chemistry: Nebulizer and flame properties in flame emission and absorption spectrometry (Recommendations 1986)' on page 1741 (https:\/\/doi.org\/10.1351\/pac198658121737)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/O04270\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/O04270\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/O04270\/plain"},"citation":"Citation: 'observation height' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.O04270","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.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","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.","accessed":"2026-05-15T09:12:54+00:00"}}