Microwave sensor for injected footwear soles, specifically developed to detect the level of degradation of the components of such soles in real-time and in a non-intrusive way.

The sensor is based on a partially filled cylindrical resonant cavity in which the fluid to be analysed flows through a duct made of a material with low microwave absorption. An electrical probe introduces energy into the resonant cavity and excites the appropriate resonant mode of operation in the cavity. The response of the resonant cavity varies as the dielectric properties of the fluid flowing within it change, resulting in a shift of the resonant frequency and a variation of the quality factor.

The measurement of these electromagnetic parameters makes it possible to characterise the physicochemical properties of the circulating fluid, monitoring its degradation and acting on a series of alarms if necessary.