Measurement of Opaque Container Contents by an M-Sequence UWB Radar

This paper deals with the method for liquid or powder level measurement inside closed non-metallic opaque containers. The proposed method uses the progressive M-sequence short-range radar technology which achieves high measurement precision and according to previous publications, allows not only the localization of the desired material interface, but is capable to estimate material properties as well. In the first part of the article, the M-sequence radar system is described. Later, the measurement technique is proposed using a low-cost microstrip transmission line as a probe. In the final parts, simulations and measurement results are presented to confirm the viability of the proposed method. The measurements show that the proposed method is able to distinguish the liquid level changes of less than 1 mm in a simple measurement setup.