A novel multiparameter and portable turbidity sensor based on polymer optical fibre is presented. For instance, the transmission and scattering of a multiwavelength light in water, allows to detect the presence of suspended particles and their optical properties. It is well known that the absorption and scattering mechanisms depend in the incident wavelength and in the defined type (refractive index), size, colour and shape of the evaluated material. Therefore the device proposed here presents one head with three separated measurements cells, corresponding to the operating wavelengths of 870 nm, 660 nm and 530 nm.
The sensor was calibrated to measure the concentration of suspended sediment and distinguish various materials, matching the real interest for post-fire erosion studies of raw run-off sample analysis device. The possibility of exploring the different optical properties of these samples to determine partial concentrations was also studied. The sensor proved to be capable of simultaneously measure the concentration of suspended sediment [1 - 10] gL−1 and to distinguish the type of particles (white, grey, yellow and red clays).