Premium
Measuring Soil Water Content, Electrical Conductivity, and Thermal Properties with a Thermo‐Time Domain Reflectometry Probe
Author(s) -
Ren T.,
Noborio K.,
Horton R.
Publication year - 1999
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1999.03615995006300030005x
Subject(s) - reflectometry , thermal diffusivity , thermal conductivity , soil water , materials science , soil thermal properties , water content , soil science , volumetric heat capacity , time domain , thermal , environmental science , composite material , hydraulic conductivity , geotechnical engineering , heat flux , heat transfer , thermodynamics , geology , computer vision , physics , computer science
Hydraulic and thermal regimes are coupled in surface soil. Accurate measurement of soil volumetric water content (θ) and thermal properties will improve our understanding of the hydraulic and thermal regimes. A thermo‐time domain reflectometry (TDR) probe was developed to simultaneously measure θ, bulk electrical conductivity (σ), thermal conductivity (λ), heat capacity (ρ c ), and thermal diffusivity (α). Time domain reflectometry was used to measure θ and σ, and the dual‐probe heat pulse (DPHP) method was used to determine λ, ρ c , and α. Laboratory tests on two soils showed that the probe determined θ accurately and the measured σ values of saturated soil correlated well with values determined by a four‐electrode probe. Measurements in agar‐immobilized water produced values of λ and ρ c that closely corresponded with standard values of these properties for water, an indication of the sensor's functionality in other media. Soil thermal properties as a function of θ also are presented. The results of these laboratory tests suggest that the thermo‐TDR probe can be a valuable tool for simultaneously monitoring θ, σ, and soil thermal properties.