In the broader sense, optical emission spectrometry includes ICP optical emission spectrometry, which uses an inductively coupled plasma (ICP) as the excitation source. The terms "optical emission spectrometry" and "photoelectric optical emission spectrometry," however, generally refer to optical emission spectrometry using spark discharge, direct-current arc discharge, or glow discharge for generating the excitation discharge.
Shimadzu optical emission spectrometers feature Pulse Distribution Analysis (PDA) to enhance the measurement reproducibility (accuracy). This method involves statistical processing of the spark pulse-generated emission spectra obtained from spark discharges in an argon atmosphere. The optical emission spectrometer offers rapid elemental analysis of solid metal samples, making it indispensable for quality control in steel making and aluminum metallurgy processes.