Principle of Flame Photometry:

Flame photometry is a technique used for the determination of elements that could be simply excited for instance, alkali and alkaline earth metals. This technique is based upon the measurement of intensity of radiation emitted, within the visible region, while a metal atom is introduced inside a flame. The wavelength of the radiation (or the colour), emitted tells us what the element is, and the intensity of the radiation tells us how much of the element is to be present. Here The International Union of Pure and Applied Chemistry that was also denoted by (IUPAC) Committee on Spectroscopic Nomenclature has recommended abbreviation FAES (flame atomic emission spectrometry) for this technique.