METHOD AND SYSTEM FOR THE OPTICAL MEASUREMENT OF A PROPERTY OF PARTICLES PRESENT IN A GASEOUS MEDIUM

The invention relates to a method and a system for the measurement of at least one property of particles present in a gaseous medium (10), such as the measurement of the number concentration or the average size of particles of soot present in an exhaust gas, by means of at least one light source (41) and a spectrometer (44). The source emits UV radiation through the gaseous medium within a measurement zone (21). The spectrometer detects at least a portion of said UV radiation having passed through the gaseous medium and generates a digital signal of the luminous intensity (50) depending on the wavelength of the portion of the UV radiation having passed through the gaseous medium. The property of the particles is then determined based on the digital signal of the luminous intensity and a reference model of variations of the Beer-Lambert Law extinction coefficient depending on the wavelength and at least the property.