Transverse sample area of two- and three-rod time domain reflectometry probes: Electrical conductivity

Paul A Ferre, Henrik H. Nissen, John H. Knight, Per Moldrup

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Numerical models have been applied successfully to the analysis of the sensitivity and transverse spatial sample areas of time domain reflectometry (TDR) probes to lateral variations in dielectric permittivity (ε). However, no similar treatment has been presented for the spatial sensitivity of TDR to lateral variations in electrical conductivity (σ). The objective of this investigation was to examine the response of conventional two- and three-rod probes to sharp changes in σ within their sample areas. The spatial weighting, predicted numerically for probes of varying geometries with sharp ε boundaries and two different σ contrasts in the plane perpendicular to the direction of wave propagation, shows good agreement with the TDR-measured σ. For low-loss conditions the sensitivity distribution of TDR is shown to be independent of the value of σ. This demonstrates that the spatial sensitivities to dielectric permittivity and electrical conductivity are the same for these conditions and that TDR-measured water contents can be used to correct TDR-measured σ for water content effects.

Original languageEnglish (US)
JournalWater Resources Research
Volume39
Issue number9
StatePublished - Sep 2003

Fingerprint

time domain reflectometry
electrical conductivity
probe
Water content
Permittivity
permittivity
sampling
Wave propagation
Numerical models
water content
Geometry
wave propagation
Electric Conductivity
geometry

Keywords

  • Electrical conductivity
  • Monitoring
  • Sample area
  • Time domain reflectometry

ASJC Scopus subject areas

  • Environmental Science(all)
  • Environmental Chemistry
  • Aquatic Science
  • Water Science and Technology

Cite this

Transverse sample area of two- and three-rod time domain reflectometry probes : Electrical conductivity. / Ferre, Paul A; Nissen, Henrik H.; Knight, John H.; Moldrup, Per.

In: Water Resources Research, Vol. 39, No. 9, 09.2003.

Research output: Contribution to journalArticle

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