Non-contacting moisture sensing using a dedicated UWB time domain instrument

This paper presents a method for the moisture determination of small and irregularly shaped objects independent of their shape and orientation. The objects under test are illuminated by UWB-pulses and the scattered pulses are received by an array of antennas. A dedicated measurement set-up and time domain transmission instrument is proposed. The scattered pulses contain information about the geometric as well as the dielectric properties. In order to separate this information multivariate calibration is applied to the time domain data. The moisture content of the objects can be determined with an accuracy of prediction of 0.69% while the range of moisture is within about 5% to 24%.