appearance temperature, \(T_{\text{app}}\)

in electrothermal atomization
The temperature of the atomization surface at which the analyte signal/@N04175@ (S/N) ratio reaches a value of 3 when the quantity of analyte in the atomizer is one hundred times the characteristic mass for peak high absorption.
PAC, 1992, 64, 253. (Nomenclature, symbols, units and their usage in spectrochemical analysis - XII. Terms related to electrothermal atomization (IUPAC Recommendations 1992)) on page 257 [Terms] [Paper]