The integrated Peak Area, also called the power spectral density (PSD), is exactly what it sounds like: it is the integrated area under a peak in a spectrum. This gives a scalar value with a meaning that depends on the units of the spectrum. For example, in SpectraWiz’s Scope Mode, the units are counts, so the area is countsᐧnm. The absolute number doesn’t mean much, but it can be used to calculate relative concentrations. For example, doubling the concentration of an emitter will double the peak area. This is generally more accurate than using the peak height.
When using radiometric units, this integrates out the spectral component. For example, if the units are spectral irradiance (W·m-2·nm-1), the integrated peak area is irradiance (W·m-2) for the wavelength range of the peak.
