New dielectric sensors and sensing techniques for soil and snow moisture measurements

Sensors (Basel). 2009;9(4):2951-67. doi: 10.3390/s90402951. Epub 2009 Apr 22.


Measurements of material moisture are essential in fields such as agriculture or civil engineering. Electromagnetic techniques, more precisely dielectric methods, have gained wide acceptance in the last decades. Frequency or Time Domain methods take advantage of the high dielectric permittivity of water compared to dry materials. This paper presents four new dielectric sensors for the determination of soil or snow water content. After a short introduction into the principles, both the hardware and operating mode of each sensor are described. Field test results show the advantages and potentials such as automatic measurement and profiling, state-of-ground detection or large-scale determination. From the results it follows that the presented sensors offer promising new tools for modern environmental research.

Keywords: Dielectrics; Electromagnetics (EM); Frequency Domain (FD); Time Domain Reflectometry (TDR); snow moisture; soil moisture (SM).