The issues of development and optimization of cuvette turbidimeters for water turbidity control are considered. The principle of constructing a universal turbidimeter with a variable course of the liquid beam inside the cuvette is described. The problem of optimization of cuvette laser turbidimeters in the mode of the presence of a rigid coupling function between the varying value of the initial laser radiation intensity and the length of the beam path in the liquid in the cuvette is investigated. It is shown that a turbidimeter with a changing beam path in a cuvette and a changing radiation intensity can have the highest average integral sensitivity if a decrease in the beam path is accompanied by a proportional logarithmic increase in the radiation intensity.

A method of water turbidity control using ratio turbidimeters is proposed for the implementation of optimal distributed water purification. The problem of minimizing the total turbidity value in NTU units of readings generated at the outputs of ratio turbidimeters included in each subchannel of the water flow distribution network is substantiated and solved. In the subchannels, the water is purified using coagulation-flocculation technology. The optimal ratio of the turbidimeter signals of the ratio is obtained, at which the sum of the NTU readings of the subchannels reaches a minimum.