Atomic emission and atomic absorption spectrometry:

Basic difference between atomic emission (AES) and atomic absorption (AAS) spectrometry is the source of radiation and the measured parameter. In AES, the source of radiation is sample itself where the energy for excitation of analyte atoms is supplied through plasma, a flame, an oven or an electric spark or arc. The signal is the measured intensity of the source at the wavelength of interest. On the other hand in that case of AAS, a source of radiation is a line source such as hollow cathode lamp. A signal is in terms of absorbance calculated from the radiant power of the source and the resulting power after the radiation has passed through the atomised sample.