Literature : TDR (Time Domain Reflectometry) (sowacs Soil Water Content Sensors and Measurement)

sowacs.com
					Literature collection TDR (Time Domain Reflectometry) Soil Water Content Sensors

contents
HOME
SENSORS
COMPARISONS
SUPPLIERS

ABOUT
CONTACT
SITE MAP
ADVERTS

NEW ENTRIES

FEATURE
HOSTED PAGES
LITERATURE

Tensiometers
TDR
VDD
FDR
Gypsum Blocks
Watermark
Heat Dissipation
Conductivity
voltammetric
Psychrometry
Neutron Probes
SH3
Other
Aqua-tel
Acoustic methods
Phase Transmission method (virrib).
Infra red sensors

Other sensors

email discussion group
SUBSCRIBE INFO
ARCHIVES

related
WIRELESS
IRRIGATION
SCHEDULING

LINKS

OTHER SENSORS

On this page:

On line papers

Other papers

Papers with abstract

(See also)

the Comparison Papers

On line papers Top

Telemetric and Multiplexing Enhancement of Time Domain Reflectometry Measurements
by Fei-chiu Huang

WMRU USDA-Agricultural Research Service, Conservation and Production Research Laboratory, Bushland, TX provides the following online resources:
http://www.cprl.ars.usda.gov/programs/

Name             Size   Last Modified    Description

ENWATBLZ.EXE   271001  12-06-96 12:42p  Energy & Water Balance Model
    Self-extracting ZIP file with documentation,
       source code & example data files.
TR200TST.EXE    55370  12-05-96  3:00p  Controls TDR Multiplexer
TR200TST.BAS    27702  12-05-96  2:59p  BASIC source code
TR200TST.INI       72  12-05-96  1:58p  Initialization file
TACQ.EXE       447517  02-25-98  9:43a  TDR system control program
README.TAC       4646  02-05-98  1:51p  TACQ.EXE version history
TACQ_WPD.ZIP   606569  12-05-97  5:12p  TDR system documentation,
                                           Wordperfect 6.1

Online articles at the ITI TDR Clearing house (Northwestern University Infrastructure Technology Institute, Evanston IL)

General

Applications of time domain reflectometry in the mining industry (K.M. O'Connor and L.V. Wade)
HTML version only (31K)

Telemetric and multiplexing enchancement of time domain reflectometry measurements (Fei-chiu Huang and Charles H. Dowding)
HTML (27K) or PDF version (35K)

Theoretical background for the TDR methodology (Henrik H. Nissen and Per Moldrup)
HTML version only (27K)

Time domain reflectometry (J. R. Andrews)
HTML version only (21K)

Soil Moisture

Effect of bulk electrical conductivity on TDR measurement of water content in porous media (I. White, S. J. Zegelin, G. C. Topp, and A. Fish)
HTML version only (45K)
Effects of physical nonequilibrium conditions on calibration and interpretation of TDR for use in solute transport studies (D. Mallants, M. Vanclooster, J. Dield, and J. Feyen)
HTML version only (47K)
An indirect calibration procedure for using TDR in solute transport studies (Marnik Vanclooster, Carlos Gonzalez, Jan Vanderborght, Dirk Mallants, and Jan Diels)
HTML version only (34K)
Influence of iron and titanium on water content determination by TDR (D.A. Robinson, J.P. Bell, and C.H. Batchelor)
HTML version only (16K)
A new method of measuring density and moisture content of soil using the technique of time domain reflectometry (S.I. Siddiqui, V. P. Drnevich)

Stahli M and Stadler D (1997) Measurement of water and solute dynamics in freezing soil columns with time domain reflectometry Journal of Hydrology 195 352-369.

Persson M (1997) Soil solution electrical conductivity measurements under transient conditions using time domain reflectometry Division S1 Soil Physics Soil Science Society of America Journal 61 (4) 997-1003.

GeoApplications of Time Domain Reflectometry by Kevin M. O'Connor and Charles H. Dowding (first chapter in pdf format - the book is on sale).

References specifically covering CS615 probes.

Delin, G.N., and Herkelrath, W.N., 1998, Long-term monitoring of soil moisture using CS615 reflectometer probes, in 1998 Fall Meeting Supplement, San Francisco, California, December 6-10, 1998: EOS, Transactions, American Geophysical Union, v. 79, no. 45, p. F368. Abstract
Wyseure GCL Mojid MA and Malk MA (1997) Measurement of volumetric water content by TDR in saline soils European Journal of Soil Science 48 347-354.
Little KM Metelerkamp B Smith CW (1998) A comparison of three methods of soil water content determination S Afr Tydskr Plant Grond 15 (2) 80-89.
Spittlehouse D (1998) Time domain reflectometry (TDR) field experiences and new developments Joing technical session CSAM/CSSS (GET INFORMATION FROM Dave Spittlehouse at dave.spittlehouse@gems4.gov.bc.ca)
J. Bilskie. Using Dielectric Properties to Measure Soil Water Content. Sensors July 1997, pp26+

This good list of references courtesy
Jean-Paul Laurent, Chargé de Recherche au CNRS

List of references (loads well in Excell) BiblioTDR.csv

Thèse Pierre Lobel.zip, "Problèmes de diffraction inverse..., application à l'imagerie microondes", Université de Nice, 1996, (fichier Poscript lisible par Ghostview compressé avec Winzip, environ 3 Mo)

Thèse Luiz Pereira dos Santos.pdf, LTHE, 1997 (106 pages).

Thése Tarik Zakri.pdf, LTHE, 1997 (202 pages).

Thèse Pierre Todoroff.pdf, Université de la Réunion, 1998, (129 pages)

Resumé Thése Max Hilhorst.pdf, "Dielectric Characterization of Soil", Wageningen, 1998

98 AIEA paper.PDF : communication JPL au Meeting de consultants organisé par l'IAEA en Novembre 1998.

Other papers Top

Zakri T., Laurent J.P., “Time domain reflectometry techniques for water-content measurement“, High Temperatures - High Pressures, Vol. 29, 1997.

Tarik Zakri, ingénieur ENS-PG (INPG), thèse soutenue le 10 Octobre 1997, titre du mémoire : “Contribution à l’étude des propriétés électriques de matériaux poreux humides en vue de l’estimation de leur teneur en eau par mesures diélectriques : modèles de mélanges et résultats expérimentaux”.(PDF)

Luiz Pereira dos Santos, thèse soutenue le 28 novembre 1997, titre du mémoire : “Développement d’une nouvelle méthode de mesure des profils de teneurs en eau dans les sols par inversion d’un signal TDR“.(PDF)

Romeu Andrè Pieritz, thèse soutenue le 2 décembre 1998, titre du mémoire : “Modélisation et simulation de milieux poreux par réseaux topologiques “.

Calibration of the Aquaflex Soil Moisture-Monitoring Unit - Ryan Krake, Masters Project, University of Melbourne, Australia.

A laboratory comparison of some currently available soil moisture monitoring devices - J P Tyndale-Biscoe and H Malano. Agricultural Engineering Australia, Vol 22 Nos 1 & 2 (1993).

On farm irrigation scheduling decision making using weather forecast: Interim Report - ML Wood, HM Malano and TA McMahon (1996). International Conference on Agricultural Engineering, Madrid 23-26 September 1996, Vol 2

The Australian researchers also produced a series of very comprehensive reports on their findings for the project funders, Goulburn Murray Water and the Land and Water Research Development Corporation (Australia). I doubt there have been many more extensive and detailed investigations into soil moisture sensor performance. Hopefully, the final report will find its way into published papers soon.

Spatial averaging of water content by time domain reflectometry: Implications for twin rod probes with and without dielectric coatings. 1996. Ferre PA, Rudolph DL & Kachanoski RG.
Water Resources Research 32:2 271-279

Measurement of soil water content, heat capacity, and thermalk conductivity with a single TDR probe. 1996. Noborio K, McInnes KJ, & Heilman JL. Soil Science 161:1 22-28

Sheets, Keith R. Hendrickx, Jan M.H. Noninvasive soil water content measurement using electromagnetic induction (Paper 95WR01949). Water resources research. OCT 01 1995 v 31 n 10 Page:2401

The following list courtesy of the TDR clearing house:

Effect of bulk electrical conductivity on TDR measurement of water content in porous media (I. White, S. J. Zegelin, G. C. Topp, and A. Fish)
HTML version only (45K)

Effects of physical nonequilibrium conditions on calibration and interpretation of TDR for use in solute transport studies (D. Mallants, M. Vanclooster, J. Dield, and J. Feyen)
HTML version only (47K)

An indirect calibration procedure for using TDR in solute transport studies (Marnik Vanclooster, Carlos Gonzalez, Jan Vanderborght, Dirk Mallants, and Jan Diels)
HTML version only (34K)

Influence of iron and titanium on water content determination by TDR (D.A. Robinson, J.P. Bell, and C.H. Batchelor)
HTML version only (16K)

A new method of measuring density and moisture content of soil using the technique of time domain reflectometry (S.I. Siddiqui, V. P. Drnevich)

Effect of Slinity on TDR measurement

Can. Geotech Journal, 1985, No 22, pp 95-101, DE Pattersson & MW Smith. "Unfrozen water content in saline soils: results using time-domain reflectometry"

Temperature Dependance of TDR measurement

Verstricht, J., B. Neerdael, P. Meynendonckx, G. Volckaert. 1994. Clay Moisture Measurements in Radioactive Waste Disposal Research. Proceedings of the Symposium on Time Domain Reflectometry in Environmental, Infrastructure, and Mining Applications, Evanston, Illinois , Sept 7-9, U.S. Bureau of Mines, Special Publication SP 19-94, NTIS PB95-105789, pp. 337-348

"Based on linear regression we found the travel time to increase at the rate of 8.1 picoseconds per degree-C, so a temperature increase of 10 degrees-C has the same effect as an increase in water content of about 2%."

Alven-s, G., and M. Stenberg. 1995. Problems in estimating soil water content by TDR measurements. Paper in the Proceedings of the Symposium: Time-Domain Reflectometry Applications in Soil Science, (Foulum, Denmark, Sept 16, 1994) SP Report No. 11, June, Vol. 3, pp. 121-123.

"noticed a dependence of temperature on the estimated soil water content. In particular, the daily oscillation in estimated soil water content has been found to be synchronized with daily temperature oscillation. The difference between the highest and lowest water contents during a clear day could be as high as 5%."

Halbertsma, J., E. van den Elsen, H. Bohl, and W. Skierucha. 1995. Temperature effects on TDR determined soil water content. Paper in the Proceedings of the Symposium: Time-Domain Reflectometry Applications in Soil Science, (Foulum, Denmark, Sept 16, 1994) SP Report No. 11, June, Vol. 3, pp. 35-37.

"It found that for sand, loam, and peat there exists a clear temperature effect on the TDR-measured water content. This effect can be compensated for, using our model-based correction or the correction of Ledieu et al (1986). However, clay soils behave differently - the TDR-measured water content showed no temperature effect."

Papers with abstract Top

Topp, G. C., M. Yanuka, W. D. Zebchuk, and S. Zegelin. 1988. Determination of Electrical Conductivity Using Time Domain Reflectometry: Soil and Water Experiments in Coaxial Lines. Water Resources Research, Vol. 24, No. 7, July, pp. 945-952.

The simultaneous measurement of water content and electrical conductivity of soils and KCL solutions was achieved using time domain reflectometry (TDR). Coaxial transmission lines varying in length from 90 to 300 mm contained either KCL solutions or soil of varied water and salt content. The water content of soil or dielectric constant of the water solutions was determined from the travel time. The measured dielectric constant of KCL solutions was unchanged from that of pure water (81) at those concentrations where there was sufficient reflected signal for measurement. Two analyses were used for determination of electrical conductivity, one based on signal attenuation after one "round trip" and the second based on a thin sample approximation for the signal reflection and attenuation. Reference measurements of conductivity were made on the same samples using low frequency conductance bridge measurements. These analyses of the TDR traces showed that, for water solution, both the thin sample analysis and the analysis after a signal had traversed one round-trip yielded conductivity in agreement with bridge conductivity values. This indicated that the imaginary part of the complex dielectric constant was negligible. For soils, the thin sample was in general agreement with the bridge measurements. From the analysis of signal after one round-trip in soils there was indication that the imaginary part of the dielectric constant should not be assumed be negligible. Further investigation of the frequency dependence of the dielectric constant and attenuation will be required to identify the relative contributions of the real and imaginary parts of the dielectric constant to measurement by TDR. The effect of impedance-matching transformers on conductivity measurements in the field has yet to be ascertained.

Janoo, V., R. L. Berg, E. Simonsen, and A. Harrison. 1994. Seasonal Changes in Moisture Content in Airport and Highway Pavements. Proceedings of the Symposium on Time Domain Reflectometry in Environmental, Infrastructure, and Mining Applications, Evanston, Illinois, Sept 7-9, U.S. Bureau of Mines, Special Publication SP 19-94, NTIS PB95-105789, pp. 357-363

With the introduction of the Strategic Highway Research Program Long-Term Pavement Performance Study, there has been an increased effort to determine the influence of environmental factors such as temperature and moisture on pavement performance. The Federal Aviation Administration (FAA) continues to sponsor research to improve its pavement design and evaluation procedures; the effect of environmental factors is one of its considerations. The new Denver airport was instrumented for this study. The Corps of Engineers (COE) has instrumented other smaller airports to study the effect of freeze-thaw on pavement performance. The COE is also involved in the study of highway pavement performance subjected to freeze-thaw cycling in Vermont, Maine, New Hampshire, and Minnesota. The moisture content in the pavement structure is measured with the time domain reflectometry (TDR) method. We observed the seasonal changes not only in the soil but also in portland cement concrete pavements. Preliminary results show a few significant problems with this method in some types of soil and at high degrees of saturation. The paper presents some early results and discusses the problems observed at some of the test sites.

Stein, J. and D. L. Kane. 1983. Monitoring the Unfrozen Water Content of Soil and Snow Using Time Domain Reflectometry. Water Resources Research, Vol. 19, No. 6, Dec., pp. 1573-1584.

Time domain reflectometry is a technique that can be used to directly measure the insitu moisture content of soil. The principal objectives of this field investigation were, apply the TDR technique to monitor the unfrozen water content in the soil, utilize this technique to determine snowmelt infiltration into seasonally frozen soils, and explore the feasibility of using the TDR technique to monitor snowmelt percolation in the snowpack. An additional goal of this paper was to explain in a straightforward manner how to use the TDR technique to obtain the liquid water profile in a soil. Various configurations of parallel transmission lines were installed horizontally at various depths in the soil and also in the snowpack. This technique gave good delineation of the unfrozen water content with depth in frozen soils. Results looked promising in snow if insitu snow density measurements were taken along with the TDR measurements.

THIS SPACE COULD BE YOUR FEATURE ARTICLE

Campbell Scientific

supports Sowacs

Data Logging Application and Measurement Systems Engineers

Soil Moisture Meter

Remote data acquisition and control systems

PRISM - CMP by Irrigation Scheduling Methods, Inc.

Research, Products, Consultancy on Real-Time Water Dynamics

SIDEBAR

Comparison page feature article

Unsure where to start? ..
then read this overview and description of tensiometers and whether to choose these over other more advanced sensors. Also discussed are soil water sensor with respect to automated weather stations. By Tom A. Murphy. Then move on through the list.

» Some basic theory of soil water physics..

your company logo here

sowacs.com

the
web
resource
for

soil water content sensors

sowacs.com
	the web resource for
soil water content sensors

On this page: On line papers Other papers Papers with abstract

On line papers Other papers Papers with abstract