Turbidity sensor for underwater applications

Turbidity is one of the main hindrances, when using optical methods, in achieving good imaging and ranging qualities in underwater applications of remote sensing, ROVs and instruments. The present paper gives the principles of operation and design of an optical turbidity meter. The operation of the meter is based on illuminating the medium with light of selected wavelengths and measuring the backscattered light. Many series of measurements were made with the sensor under discussion based on secondary standard calibration mediums of formazin. The experimental results in calibration mediums and from actual underwater applications are presented in this paper. Finally, the performance of the sensor system in practical applications is described. The main aspects of the sensor electronics is also presented.