{"term":{"id":"04305","title":"optical-beam error","longtitle":"IUPAC Gold Book - optical-beam error","doi":"10.1351\/goldbook.O04305","code":"O04305","status":"current","definitions":[{"id":1,"text":"For wavelength-scanning spectrometers, an error may be introduced if the image position on the photodetector changes. Reflection of the incident radiation, e.g. between the cell walls, is another source of error and results in a measured absorbance slightly higher than the true absorbance. These errors are collectively termed optical-beam errors.","contexts":[],"links":[{"term":"absorbance","url":"https:\/\/goldbook.iupac.org\/terms\/view\/A00028"},{"term":"wavelength","url":"https:\/\/goldbook.iupac.org\/terms\/view\/W06659"}],"sources":["PAC, 1988, 60, 1449. 'Nomenclature, symbols, units and their usage in spectrochemical analysis - VII. Molecular absorption spectroscopy, ultraviolet and visible (UV\/VIS) (Recommendations 1988)' on page 1457 (https:\/\/doi.org\/10.1351\/pac198860091449)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/O04305\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/O04305\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/O04305\/plain"},"citation":"Citation: 'optical-beam error' 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.O04305","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":"2026-06-30T14:14:15+00:00"}}