DOI QR코드

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Design, analyses, and evaluation of a spiral TDR sensor with high spatial resolution

  • Gao, Quan (Department of Civil Engineering, Case Western Reserve University) ;
  • Wu, Guangxi (Department of Electrical Engineering and Computer Science, Case Western Reserve University) ;
  • Yu, Xiong (Department of Civil Engineering, Case Western Reserve University)
  • 투고 : 2014.11.06
  • 심사 : 2015.04.30
  • 발행 : 2015.10.25

초록

Time Domain Reflectometry (TDR) has been extensively applied for various laboratory and field studies. Numerous different TDR probes are currently available for measuring soil moisture content and detecting interfaces (i.e., due to landslides or structural failure). This paper describes the development of an innovative spiral-shaped TDR probe that features much higher sensitivity and resolution in detecting interfaces than existing ones. Finite element method (FEM) simulations were conducted to assist the optimization of sensor design. The influence of factors such as wire interval spacing and wire diameter on the sensitivity of the spiral TDR probe were analyzed. A spiral TDR probe was fabricated based on the results of computer-assisted design. A laboratory experimental program was implemented to evaluate its performance. The results show that the spiral TDR sensor featured excellent performance in accurately detecting thin water level variations with high resolution, to the thickness as small as 0.06 cm. Compared with conventional straight TDR probe, the spiral TDR probe has 8 times the resolution in detecting the water level changes. It also achieved 3 times the sensitivity of straight TDR probe.

키워드

참고문헌

  1. Benson, C.H., and Bosscher, P.J. (1999), "Time-domain reflectometry (TDR) in geotechnics: a review", Nondestructive and Automated Testing for Soil and Rock Properties, ASTM STP, 1350, 113-136.
  2. Bin, Z., Xinbao, Y. and Xiong, Y. (2010), "Design and evaluation of a distributed TDR moisture sensor", Smart Struct. Sys., 6(9), 1007-1023. https://doi.org/10.12989/sss.2010.6.9.1007
  3. Bittelli, M., Flury, M., Campbell, G.S. and Schulz, V. (2004), "Characterization of a spiral-shaped time domain reflectometry probe", Water Resour Res., 40(9).
  4. Chen, G., Mu, H., Pommerenke, D. and Drewniak, J.L. (2004), "Damage detection of reinforced concrete beams with novel distributed crack/strain sensors", Struct. Health Monit., 3(3), 225-243. https://doi.org/10.1177/1475921704045625
  5. Drnevich, V.P., Siddiqui, S.I., Lovell, J. and Yi, Q. (2001), "Water content and density of soil insitu by the purdue TDR method", Proceedings of the 2nd International Symposium on Time Domain Reflectometry.
  6. Fagert, J., Zhang, B., Gao, Q. and Yu, X.B. (2014), Sensor for detection of earthquake induced void redistribution in multi-layered soil system.
  7. Ferre, P., Knight, J., Rudolph, D. and Kachanoski, R. (1998), "The sample areas of conventional and alternative time domain reflectometry probes", Water Resour Res., 34(11), 2971-2979. https://doi.org/10.1029/98WR02093
  8. Ferre, P., Knight, J., Rudolph, D. and Kachanoski, R. (2000), "A numerically based analysis of the sensitivity of conventional and alternative time domain reflectometry probes", Water Resour Res., 36(9), 2461-2468. https://doi.org/10.1029/2000WR900119
  9. Ferre, P., Rudolph, D. and Kachanoski, R. (1996), "Spatial averaging of water content by time domain reflectometry: Implications for twin rod probes with and without dielectric coatings", Water Resour Res., 32(2), 271-279. https://doi.org/10.1029/95WR02576
  10. Ferre, P.A., Nissen, H.H., Moldrup, P. and Knight, J.H. (2001), "The sample area of time domain reflectometry probes in proximity to sharp dielectric permittivity boundaries", Proceedings of the TDR 2001 2nd International Symposium and Workshop on Time Domain Reflectrometry for Innovative Geotechnical Applications, Infrastructure Technology Institute, Northwestern University, Evanston, IL.
  11. Hager III, N, and Domszy, R. (2004), "Monitoring of cement hydration by broadband time-domain-reflectometry dielectric spectroscopy", J. Appl. Phys., 96(9), 5117-5128. https://doi.org/10.1063/1.1797549
  12. Haridy, S.A., Persson, M. and Berndtsson, R. (2004), "Estimation of LNAPL saturation in fine sand using time-domain reflectometry/Estimation de la saturation en LPNAL dans du sable fin grace a la reflectometrie en domaine temporal", Hydrolog. Sci. J., 49(6).
  13. Katsura, S.Y., Kosugi, K.I. and Mizuyama, T. (2008), "Application of a coil-type TDR probe for measuring the volumetric water content in weathered granitic bedrock", Hydrol Process, 22(6), 750-763. https://doi.org/10.1002/hyp.6663
  14. Knight, J. (1992), "Sensitivity of time domain reflectometry measurements to lateral variations in soil water content", Water Resour Res., 28(9), 2345-2352. https://doi.org/10.1029/92WR00747
  15. Knight, J., Ferre, P., Rudolph, D. and Kachanoski, R. (1997), "A numerical analysis of the effects of coatings and gaps upon relative dielectric permittivity measurement with time domain reflectometry", Water Resour Res., 33(6), 1455-1460. https://doi.org/10.1029/97WR00435
  16. Lin, M.W., Thaduri, J. and Abatan, A.O. (2005), "Development of an electrical time domain reflectometry (ETDR) distributed strain sensor", Measurement Sci. Technol., 16(7), 1495. https://doi.org/10.1088/0957-0233/16/7/012
  17. Liu, Z., Yu, X., Yu, X. and Gonzalez, J. (2012), "Time domain reflectometry sensor-assisted freeze/thaw analysis in geomaterials", Cold Reg. Sci. Technol., 71, 84-89. https://doi.org/10.1016/j.coldregions.2011.10.002
  18. Lungal, M. and Si, B.C. (2008), "Coiled time domain reflectometry matric potential sensor", Soil. Sci. Soc. Am. J., 72(5), 1422-1424. https://doi.org/10.2136/sssaj2007.0166N
  19. Nissen, H.H., Ferre, T. and Moldrup, P. (2003), "Sample area of two-and three-rod time domain reflectometry probes", Water Resour Res., 39(10).
  20. Nissen, H.H., Moldrup, P. and Henriksen, K. (1998), "High-resolution time domain reflectometry coil probe for measuring soil water content", Soil. Sci. Soc. Am. J., 62(5), 1203-1211. https://doi.org/10.2136/sssaj1998.03615995006200050008x
  21. Noborio, K. (2001), "Measurement of soil water content and electrical conductivity by time domain reflectometry: a review", Comput. Electron. Agr., 31(3), 213-237. https://doi.org/10.1016/S0168-1699(00)00184-8
  22. O'Connor, K.M. and Dowding, C.H. (1999), Geomeasurements by pulsing TDR cables and probes, CRC Press.
  23. Selker, J.S., Graff, L. and Steenhuis, T. (1993), "Noninvasive time domain reflectometry moisture measurement probe", Soil. Sci. Soc. Am. J., 57(4), 934-936. https://doi.org/10.2136/sssaj1993.03615995005700040009x
  24. Siddiqui, S.I. and Drnevich, V. P. (1995), Use of Time Domain Reflectometry for Determination of Water Content and Density of Soil, Technical Report.
  25. Su, M.B. and Chen, Y.J. (1998), "Multiple reflection of metallic time domain reflectometry", Exper. Tech., 22(1), 26-29. https://doi.org/10.1111/j.1747-1567.1998.tb00584.x
  26. Topp, G.C. and Davis, J.L. (1985), "Measurement of Soil Water Content Using Time Domain Reflectometry (TDR): A Field Evaluation", Soil. Sci. Soc. Am. J., 49(3), 35-39.
  27. Vaz, C.M.P. and Hopmans, J.W. (2001), "Simultaneous measurement of soil penetration resistance and water content with a combined penetrometer-TDR moisture probe", Soil. Sci .Soc. Am. J., 65(1), 4-12. https://doi.org/10.2136/sssaj2001.6514
  28. White, I. and Zegelin, S.J. (1994), "Comments on 'Considerations on the use of time-domain reflectometry (TDR) for measuring soil water content'by WR Whalley", Eur. J. Soil. Sci., 45(4), 503-508. https://doi.org/10.1111/j.1365-2389.1994.tb00536.x
  29. Yu, X. (2009), Experimental Study of an Innovative Bridge Scour Sensor, Ph.D. Dissertation, Case Western Reserve University.
  30. Yu, X. and Drnevich, V.P. (2004), "Soil water content and dry density by time domain reflectometry", J. Geotech. Geoenviron., 130(9), 922-934. https://doi.org/10.1061/(ASCE)1090-0241(2004)130:9(922)
  31. Yu, X. and Yu, X. (2009), "Time domain reflectometry automatic bridge scour measurement system: principles and potentials", Struct. Health Monit., 8(6), 463-476. https://doi.org/10.1177/1475921709340965