Abstract

A novel fibre optic sensor has been developed, which is capable of accurately measuring yeast concentrations in suspension over a range of 0 to 16 g/1. To date a solution for on-line measurement of suspended particulate masses such as yeast has proved difficult and expensive for many industrial users. The sensor reported in this paper relies upon light being radiated through the cladding of one fibre and detected at the end of an adjacent receiving fibre (Fig. 1). Some light is coupled with no yeast present, but the received intensity grows as yeast concentration increases and more light is scattered into the receiving fibre (Fig. 1). The process of scattering is well understood for controlled laboratory conditions where small spherical particles of predetermined diameters have been employed.^1,2

© 1994 IEEE