High Accuracy Thickness Measurements of Conducting Material with Single FMCW Radar Sensor

A novel quasi-optical measurement setup for measuring the thickness of conducting materials, e.g. steel sheets, is presented. It utilizes a single ultra wide band frequency-modulated continuous-wave (FMCW) radar, operating from 68 to 90 G Hz. To demonstrate the capabilities of the presented approach, we perform thickness measurements with spring steel sheets with thicknesses from 300 μm to 950 μm, The measurements show accuracies in the micrometer range and a measurement reproducibility of ±3.2 μm is achieved.