Ma. Malicki et al., IMPROVING THE CALIBRATION OF DIELECTRIC TDR SOIL-MOISTURE DETERMINATION TAKING INTO ACCOUNT THE SOLID SOIL, European journal of soil science, 47(3), 1996, pp. 357-366
The influence of soil's solid phase on the dielectric constant of the
soil over a range of moisture contents has been studied. Samples of so
il, soil-like, and also other porous materials were analysed using Tim
e Domain Reflectometry (TDR) to determine the contribution of bulk den
sity and porosity to the function that relates dielectric constant to
water content. The study showed that bulk density, and thus also poros
ity, substantially affects the relation between dielectric constant an
d water content. Two equivalent, empirical, normalized conversion func
tions were found, one accounting for bulk density and the other for po
rosity. Each of them reduced the root mean square error of the dielect
ric TDR determinations of moisture to 0.03, regardless of the material
's bulk density and porosity.