New method for measuring of refractive index in flow-ing liquid

The necessity of developing a new method for measuring the refractive index of a liquid in a turbulent mode of its flow in a pipeline is substantiated. A new method for measuring the refractive index of a medium $n$ is presented. For its practical implementation, a new design of a flow-through refractometer has been developed, which makes it possible to measure $n$ in both laminar and turbulent fluid flow. A new design of the optical part of the refractometer is considered. A new way of placing it on the vertical section of the pipeline for measuring $n$ is proposed. All this makes it possible to make insignificant the influence on the measurement result of $n$ flowing liquid of errors associated with multiple reflections of laser radiation from optical elements, with the formation of voids or vortex flows in the pipeline and with temperature fluctuations. In the design of a refractometer with a new method for measuring $n$, there are no restrictions on determining the value of $n$ of a flowing liquid, in contrast to the used industrial flow-through refractometers, the principle of which is based on the phenomenon of total internal reflection of laser radiation at the interface of two media. The results of experimental studies of various media are presented.