The modelling of inductively coupled plasmas spectroscopic emission (ICP-OES) has been developed for the diagnostic of plasmas used in spectrochemical analysis or in material processing. The modelling of the plasma was coupled with the complete modelling of the spectroscopic emission assuming local thermodynamic equilibrium (LTE). Through integration of phenomena over the spatial range of optical measurements, one can predict the characteristics of the collected signals with a simplified measurement set-up, making the approach suitable for industrial environments. To validate this modelling, the spectroscopic signals predicted by the model have been compared with experimental data collected in laboratory on a low power (1-2 kW) plasma source at 27 MHz used for spectrochemical analysis. Some discrepancies are noted between predicted and observed data but are low in pure argon plasmas. These features enables one to monitor industrial processes with simplified spectroscopic devices.