Design of a slim-line integrated probe using optical fibre technology that is suitable for microwave environments and measures reflection spectroscopy and temperature

The work presented describes the development of a novel integrated optical sensor system for the simultaneous and online measurement of colour and temperature of food as it cooks in a large-scale microwave and hybrid oven systems. The integrated probe contains two different sensor concepts, one to monitor temperature, based on Fibre Bragg Grating (FBG) technology and a second for food quality, based on reflection spectroscopy in the visible wavelength range. The in-house designed probe was used to obtain measurements of product temperature in a conventional and microwave oven. The performance of the FBG temperature sensor within the combined optical probe was thus evaluated for use in conventional and microwave ovens.