scholarly journals Applications of Thermo-TDR Sensors for Soil Physical Measurements

2021 ◽  
Author(s):  
Yili Lu ◽  
Wei Peng ◽  
Tusheng Ren ◽  
Robert Horton
Keyword(s):  
Electrical Properties ◽  
Time Domain ◽  
Structural Parameters ◽  
Time Domain Reflectometry ◽  
State Variables ◽  
Physical Measurements ◽  
Bulk Electrical Conductivity ◽  
Potential Applications ◽  
Thermal And Electrical Properties ◽  
Ice Content

Advanced sensors provide new opportunities to improve the understanding of soil properties and processes. One such sensor is the thermo-TDR sensor, which combines the functions of heat pulse probes and time domain reflectometry probes. Recent advancements in fine-scale measurements of soil thermal, hydraulic, and electrical properties with the thermo-TDR sensor enable measuring soil state variables (temperature, water content, and ice content), thermal and electrical properties (thermal diffusivity, heat capacity, thermal conductivity, and bulk electrical conductivity), structural parameters (bulk density and air-filled porosity) and fluxes (heat, water, and vapor) simultaneously. This chapter describes the theory, methodology, and potential applications of the thermo-TDR technique.

scholarly journals A new thermo-time domain reflectometry approach to quantify soil ice content at temperatures near the freezing point

2020 ◽  
Vol 174 ◽  
pp. 103060 ◽  
Author(s):  
Yuki Kojima ◽  
Yuta Nakano ◽  
Chihiro Kato ◽  
Kosuke Noborio ◽  
Kohji Kamiya ◽  
...  
Keyword(s):  
Time Domain ◽  
Freezing Point ◽  
Time Domain Reflectometry ◽  
Ice Content ◽  
Soil Ice Content

Accuracy of Bulk Electrical Conductivity Measurements with Time Domain Reflectometry

2008 ◽  
Vol 7 (2) ◽  
pp. 426-433 ◽  
Author(s):  
J. A. Huisman ◽  
C. P. Lin ◽  
L. Weihermüller ◽  
H. Vereecken
Keyword(s):  
Electrical Conductivity ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Conductivity Measurements ◽  
Bulk Electrical Conductivity

scholarly journals TEOR DE POTÁSSIO NA SOLUÇÃO DO SOLO COM USO DA TÉCNICA DE REFLECTOMETRIA NO DOMÍNIO DO TEMPO

Irriga ◽  
2005 ◽  
Vol 10 (4) ◽  
pp. 409-418
Author(s):  
Tibério Santos Martins da Silva ◽  
Eugênio Ferreira Coelho ◽  
Vital Pedro da Silva Paz ◽  
Lucas Melo Vellame ◽  
Gessionei Da Silva Santana
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Soil Solution ◽  
Time Domain ◽  
Potassium Concentration ◽  
Soil Disturbance ◽  
Time Domain Reflectometry ◽  
Ion Concentration ◽  
Bulk Electrical Conductivity ◽  
Water Sampler

TEOR DE POTÁSSIO NA SOLUÇÃO DO SOLO COM USO DA TÉCNICA DE REFLECTOMETRIA NO DOMÍNIO DO TEMPO  Tibério Santos Martins da Silva1; Eugênio Ferreira Coelho2; Vital Pedro da Silva Paz3; Lucas Melo Vellame1; Gessionei da Silva Santana41Universidade Federal da Bahia, Cruz das Almas, BA tibé[email protected] Mandioca e Fruticultura, Cruz das Almas, BA3Departamento de Engenharia Agrícola, Universidade Federal da Bahia, Cruz das Almas, BA4Universidade Federal de Viçosa, Viçosa, MG  1 RESUMO A avaliação do teor de íons no solo no manejo da fertirrigação é complexa devido a dificuldade de obtenção em tempo real e com o mínimo de alterações na estrutura do solo. Este trabalho teve como objetivo estimar o teor de potássio na solução do solo, a partir de modelos matemáticos ajustados, em função da condutividade elétrica da solução do solo (CEw) coletada por extrator de solução, da umidade (q) e da condutividade elétrica aparente do solo (CEa) obtidas por um equipamento de reflectometria no domínio do tempo (TDR). Os modelos estimaram razoavelmente a Cew e a reflectometria no domínio do tempo mostrou-se adequada para o monitoramento da concentração de potássio na solução do volume de solo molhado. UNITERMOS: TDR.  SILVA, T. S. M. da.; COELHO, E. F.; PAZ, V. P. da. S.; VELLAME, L. M.; SANTANA, G. da. S.; POTASSIUM CONCENTRATION IN SOIL SOLUTION USING TIME DOMAIN REFLECTOMETRY TECHNIQUE  2 ABSTRACT The evaluation of ion concentration in the soil under fertirrigation is complex due to the difficulty of obtaining it in real time, with a minimum of soil disturbance. This work aimed to estimate potassium concentration in soil solution as a function of soil solution electrical conductivity (CEw) collected by using water sampler, soil water content (q) and bulk electrical conductivity (CEa) obtained using a time domain reflectometry equipment (TDR). The models estimated reasonably CEw and time domain reflectometry was suitable for potassium concentration monitoring of wet soil volume solution. KEYWORDS: TDR. 

Measurement of soil state variables using Spatial Time Domain Reflectometry (Spatial TDR)

2013 ◽  
pp. 309-315
Author(s):  
A Scheuermann ◽  
R Becker ◽  
S Schlaeger
Keyword(s):  
Time Domain ◽  
Time Domain Reflectometry ◽  
State Variables

Laboratory Approach to Determine Roller Compacted Concrete Mixture Electrical Characteristics Using a New Time-Domain Reflectometry Interpretation Method

2021 ◽  
pp. 036119812110363
Author(s):  
Issa M. Issa ◽  
Dan G. Zollinger ◽  
Ibrahim Onifade ◽  
Robert L. Lytton
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Moisture Content ◽  
Transmission Line ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Test Configuration ◽  
Roller Compacted Concrete ◽  
Line Theory

This work deals with using time-domain reflectometry (TDR) to measure the electrical properties of roller compacted concrete (RCC). It is well known that TDR provides a non-destructive method to measure the dielectric constant toward an estimation of moisture content for soil materials. However, few studies have used TDR to determine the moisture content in concrete because of the inability to obtain TDR traces after the concrete hardens. To obtain TDR traces, a transmission circuit is initiated where a wave signal moves through the medium and reflects back in accordance with transmission line theory. In the literature, the TDR waveform has been interpreted empirically to estimate the relative permittivity (or dielectric constant) and electrical conductivity in a given material relative to the determination of associated water content. However, empirical models tend to ignore certain aspects related to the electrical properties of a medium, which has made interpretation of TDR measurements prone to systematic errors. In this paper, a new approach of test configuration and TDR response interpretation has been developed. For the test setup, the approach uses disposable metal probes that can be embedded into the concrete at different depths to obtain the TDR traces. The approach also employs the transmission line equation to estimate the dielectric constant, electrical conductivity, and reflectivity of an instrumented RCC mixture. These properties will affect the understanding of the RCC pavement behavior, especially curling and warping behavior, placement density, and development of long-term distresses.

Evaluation of a Direct-Coupled Time-Domain Reflectometry for Determination of Soil Water Content and Bulk Electrical Conductivity

2016 ◽  
Vol 15 (1) ◽  
pp. vzj2015.08.0115 ◽  
Author(s):  
Robert C. Schwartz ◽  
Steven R. Evett ◽  
Scott K. Anderson ◽  
David J. Anderson
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Bulk Electrical Conductivity

scholarly journals Advances in thermo‐time domain reflectometry technique: Measuring ice content in partially frozen soils

2020 ◽  
Vol 84 (5) ◽  
pp. 1519-1526
Author(s):  
Zhengchao Tian ◽  
Yuki Kojima ◽  
Joshua L. Heitman ◽  
Robert Horton ◽  
Tusheng Ren
Keyword(s):  
Time Domain ◽  
Time Domain Reflectometry ◽  
Frozen Soils ◽  
Ice Content

Advances in Thermo-Time Domain Reflectometry Technique: Measuring Ice Content in Partially Frozen Soils

2019 ◽  
Vol 4 (1) ◽  
pp. 0 ◽  
Author(s):  
Zhengchao Tian ◽  
Yuki Kojima ◽  
Joshua L. Heitman ◽  
Robert Horton ◽  
Tusheng Ren
Keyword(s):  
Time Domain ◽  
Time Domain Reflectometry ◽  
Frozen Soils ◽  
Ice Content
Sign in / Sign up

Export Citation Format

Share Document