alexa Comparison of Three Methods to Obtain the Apparent Dielectric Constant from Time Domain Reflectometry Wave Traces
Environmental Sciences

Environmental Sciences

Hydrology: Current Research

Author(s): D J Timlin, Ya A Pachepsky

Abstract Share this page

A calibration of time domain reflectometry (TDR) probes to measure soil water in a particular soil is desirable since no consistent relationship between water content and apparent dielectric constant (Ka) has been found. We compared three procedures to compute Ka from TDR traces: a manual method that uses a plot of the wave trace, a derivative-based computer algorithm, and fitting a simulated TDR trace to a measured one with a simple multiple reflection model. We added a model of inertia to the multiple reflection model to approximate the rise time of the cable tester. The TDR traces were measured in situ with a Tektronix 1502B cable tester (Tektronix, Inc., Wilsonville, OR) on samples from two soils with contrasting textures, Beltsville silt loam (fine-loamy, mixed, mesic Typic Fragiudult) and Rumford loamy sand (coarse-loamy, siliceous, thermic Typic Normudult). Ten-centimeter probes with three rods were used. The water contents were measured gravimetrically with soil cores. Calibration with apparent dielectric constants obtained from the derivative-based algorithm had the smallest standard error for both soils, and the manual method was better than the wave simulation method. The intercepts and slopes of the calibration equations for the manual and derivative methods were not significantly different from each other for both soils. The wave simulation method, which gives physically meaningful values for Ka, and characteristic impedances can be a useful tool for theoretical studies.

  • To read the full article Visit
  • Subscription
This article was published in Soil Science Society of America Journal and referenced in Hydrology: Current Research

Relevant Expert PPTs

Relevant Speaker PPTs

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords