The issue of the development and creation of intelligent flow rate sensors of free-flowing and fluid substances carried on pipelines is considered timely during this era of digital conversion of production processes in industry and science. With this objective, this article presents new approaches to improving the measurement precision of microwave flow rate measuring units. Taking into account the characteristics of electromagnetic waves propagating along the pipeline, analysis was conducted of a wave scattered by the inhomogeneities of the medium being monitored. The features of the transformation of a polarized scattered wave, the limiting geometrical sizes of the pipeline, and optimization of the values of the true scattered signal, are revealed. The feasibility of picking up an information signal with orthogonal polarization of the scattered wave, and via a directional coupler, is substantiated. A methodology was developed to estimate measurement precision with an association to the signal-to-noise ratio at input to a processing unit. It has been shown that the results of the studies can be used in the cryogenic engineering industry to measure the volume and mass flow rates of liquid cryoproducts.