Highly sensitive, all solid state fibre optic oxygen sensor based on the sol-gel coating technique

A fibre optic sensor probe based on the fluorescence quenching of an optically active sol-gel coating is demonstrated. The simplified probe design includes a blue LED light source, a photodiode silicon detector and a bifurcated optical fibre. The sensor performance was characterised by a detection limit of <1 ppm of oxygen vapour, a response time of <10 s and a linear dynamic range for oxygen concentrations extending from 1 to 1000 ppm