The soot emission has been the focus of many studies due to applications in industry and the prejudicial effects caused to the environment. The presence of soot is important to the heat transfer in boilers and combustion chambers, contributing significantly to efficiency increases. In controversy, the inhaled soot may cause respiratory system damage and even cancer. Another important point is the contribution to the greenhouse effect. Therefore, the aim of this work is to analyse the soot emission in laminar diffusion flames produced from commercial fuels stabilized on a burner representative of industrial applications. Methane, vehicular natural gas and liquid petroleum gas are considered as fuels. An experimental setup was constructed to implement the technique of laser light extinction and laser-induced incandescence. These non-intrusive techniques provide instant information, in real time, about soot volume fraction. The measurements were calibrated and validated using methods and results of studies available in the literature, and also the uncertainty is analysed and suitably minimized. The results will contribute to the database for projects of combustion systems optimization, aiming to increase the efficiency and soot emissions control.