volume | PIER Journals

Abstract

In this paper, the experimental validation of a time domain reflectometry (TDR)-based method for pinpointing water leaks in underground metal pipes is presented. The method relies on sensing the local change in the dielectric characteristics of the medium surrounding the leak point. The experimental validation of the method was carried out through measurements performed on a pilot plant (experimental case P1) and through on-the-field measurements performed on two `already-installed pipes', i.e., already operating and connected to the water distribution system (experimental cases P2 and P3). For the pilot plant, different leak conditions were imposed and the corresponding TDR responses were acquired and analyzed. For the onthe-field measurements, TDR measurements were performed on pipes for which a leak-detection crew had preliminarily individuated the possible presence of leaks (through traditional leak-detection methods). Finally, in view of the practical implementation of the proposed TDR-based leak-detection system, a data-processing procedure (which gives an automatic evaluation of the position of the leak) is also presented.

1. Farley, M. and S. Trow, Losses in Water Distribution Networks, 1st Ed., IWA Publishing, London, UK, 2003.

2. Puust, R., Z. Kapelan, D. A. Savic, and T. Koppel, "A review of methods for leakage management in pipe networks," Urban Water Journal, Vol. 7, No. 1, 25-45, 2010.
doi:10.1080/15730621003610878

3. Wang, G., D. Dong, and C. Fang, "Leak detection for transport pipelines based on autoregressive modeling," IEEE Transactions on Instrumentation and Measurement, Vol. 42, No. 1, 68-71, 1993.
doi:10.1109/19.206686

4. Bimpas, M., A. Amditis, and N. Uzunoglu, "Detection of water leaks in supply pipes using continuous wave sensor operating at 2.45 GHz," Journal of Applied Geophysics, Vol. 70, No. 3, 226-236, 2010.
doi:10.1016/j.jappgeo.2010.01.003

5. Cataldo, A., G. Cannazza, E. De Benedetto, and N. Giaquinto, "A new method for detecting leaks in underground water pipelines," IEEE Sensors Journal, Vol. 12, No. 6, 1660-1667, 2012.
doi:10.1109/JSEN.2011.2176484

6. Cataldo, A., G. Cannazza, E. De Benedetto, and N. Giaquinto, "Performance evaluation of a TDR-based system for detection of leaks in buried pipes," Proceedings of IEEE 2012 International Instrumentation and Measurement Technology Conference, 792-795, Graz, Austria, May 2012.

7. Apparatus and method for detection and localization of leaks and faults in underground pipes, WO Patent Pending BA2011A000034, 2011.

8. Cataldo, A., L. Catarinucci, L. Tarricone, F. Attivissimo, and A. Trotta, "A frequency-domain method for extending TDR performance in quality determination of fluids," Measurement Science and Technology, Vol. 18, No. 3, 675-688, 2007.
doi:10.1088/0957-0233/18/3/018

9. Hager, III and N. E., "Broadband time-domain-reflectometry dielectric spectroscopy using variable-time-scale sampling," Review of Scientific Instruments, Vol. 64, No. 4, 887-891, 1994.
doi:10.1063/1.1144917

10. Moradi, G. and A. Abdipour, "Measuring the permittivity of dielectric materials using STDR approach," Progress In Electromagnetics Research, Vol. 77, 357-365, 2007.
doi:10.2528/PIER07080201

11. Nozaki, R. and T. K. Bose, "Broadband complex permittivity measurements by time-domain spectroscopy," IEEE Trans. Instrum. Meas., Vol. 39, No. 6, 945-951, 1990.
doi:10.1109/19.65803

12. Cataldo, A., L. Catarinucci, L. Tarricone, F. Attivissimo, and E. Piuzzi, "A combined TD-FD method for enhanced re°ectometry measurements in liquid quality monitoring," IEEE Transactions on Instrumentation and Measurement, Vol. 58, No. 10, 3534-3543, 2009.
doi:10.1109/TIM.2009.2018009

13. Piuzzi, E., A. Cataldo, and L. Catarinucci, "Enhanced re°ectometry measurements of permittivities and levels in layered petrochemical liquids using an `in-situ' coaxial probe," Measurement, Vol. 42, No. 5, 685-696, 2009.
doi:10.1016/j.measurement.2008.11.002

14. Cataldo, A., E. Piuzzi, G. Cannazza, E. De Benedetto, and L. Tarricone, "Quality and anti-adulteration control of vegetable oils through microwave dielectric spectroscopy," Measurement, Vol. 43, No. 8, 1031-1039, 2010.
doi:10.1016/j.measurement.2010.02.008

15. Cataldo, A., E. Piuzzi, G. Cannazza, and E. De Benedetto, "Dielectric spectroscopy of liquids through a combined approach: evaluation of the metrological performance and feasibility study on vegetable oils," IEEE Sensors Journal, Vol. 9, No. 10, 1226-1233, 2009.
doi:10.1109/JSEN.2009.2029454

16. Cataldo, A., E. Piuzzi, G. Cannazza, and E. De Benedetto, "Classification and adulteration control of vegetable oils based on microwave reflectometry analysis," Journal of Food Engineering, Vol. 112, No. 4, 338-345, 2012.
doi:10.1016/j.jfoodeng.2012.04.012

17. Liu, Y., L. Tong, W.-X. Zhu, Y. Tian, and B. Gao, "Impedance measurements of nonuniform transmission lines in time domain using an improved recursive multiple reflection computation method ," Progress In Electromagnetics Research, Vol. 117, 149-164, 2011.

18. Bishop, J., D. Pommerenke, and G. Chen, "A rapid-acquisition electrical time-domain reflectometer for dynamic structure analysis," IEEE Transactions on Instrumentation and Measurement, Vol. 60, No. 2, 655-661, 2011.
doi:10.1109/TIM.2010.2058551

19. Furse, C., P. Smith, and M. Diamond, "Feasibility of reflectometry for nondestructive evaluation of prestressed concrete anchors," IEEE Sensors Journal, Vol. 9, No. 11, 1322-1329, 2009.
doi:10.1109/JSEN.2009.2019309

20. Griffiths, L. A., R. Parakh, C. Furse, and B. Baker, "The invisible fray: A critical analysis of the use of reflectometry for fray location," IEEE Sensors Journal, Vol. 6, No. 3, 697-706, 2006.
doi:10.1109/JSEN.2006.874017

21. Schuet, S., D. Timucin, and K. Wheeler, "A model-based probabilistic inversion framework for characterizing wire fault detection using TDR," IEEE Transactions on Instrumentation and Measurement, Vol. 60, No. 5, 1654-1663, 2011.
doi:10.1109/TIM.2011.2105030

22. Scheuermann, A. and C. Huebner, "On the feasibility of pressure prole measurements with time-domain reflectometry," IEEE Transactions on Instrumentation and Measurement, Vol. 58, No. 2, 467-474, 2009.
doi:10.1109/TIM.2008.928876

23. O'Connor, K. M. and C. H. Dowding, GeoMeasurements by Pulsing TDR Cables and Probes, CRC Press, UK, Jan. 1999.

24. Cataldo, A., G. Monti, E. De Benedetto, G. Cannazza, and L. Tarricone, "A noninvasive resonance-based method for moisture content evaluation through microstrip antennas," IEEE Transactions on Instrumentation and Measurement, Vol. 58, No. 5, 1420-1426, 2009.
doi:10.1109/TIM.2009.2014513

25. Cataldo, A., G. Monti, G. Cannazza, E. De Benedetto, and L. Tarricone, "A non-invasive approach for moisture measurements through patch antennas," Proc. IEEE Int. Instrum. Meas. Technol. Conf., 1012-1015, Victoria, BC, May 2008.

26. Serdyuk, V. M., "Dielectric study of bound water in grain at radio and microwave frequencies," Progress In Electromagnetics Research, Vol. 84, 379-406, 2008.
doi:10.2528/PIER08081103

27. Cataldo, A., G. Monti, E. De Benedetto, G. Cannazza, L. Tarricone, and L. Catarinucci, "Assessment of a TD-based method for characterization of antennas," IEEE Transactions on Instrumentation and Measurement, Vol. 58, No. 5, 1412-1419, 2009.
doi:10.1109/TIM.2008.2009199

28. Cataldo, A., G. Monti, E. De Benedetto, G. Cannazza, L. Tarricone, and L. Catarinucci, "A comparative analysis of reflectometry methods for characterization of antennas," Proc. IEEE Int. Instrum. Meas. Technol. Conf., 240-243, Victoria, BC, May 2008.

29. Cataldo, A., G. Monti, E. De Benedetto, and G. Cannazza, "A reliable low-cost method for accurate characterization of antennas in time domain ," Metrology and Measurement Systems, Vol. 15, No. 4, 571-583, 2008.

30. Okhovvat, M. and R. Fallahi, "Measurement of antenna reflection coe±cient in time domain," Proc. 11th International Conference on Mathematical Methods In Electromagnetic Theory, 328-330, Kharkiv, Ukraine, Jun. 2006.
doi:10.1109/MMET.2006.1689783

31. Cataldo, A. and E. De Benedetto, "Broadband reflectometry for diagnostics and monitoring applications," IEEE Sensors Journal, Vol. 11, No. 2, 451-459, 2011.
doi:10.1109/JSEN.2010.2060322

32. Dyer, S. A., Survey of Instrumentation and Measurement, John Wiley & Sons Inc., USA, 2001.

33. Mohamed, A. M. O., Principles and Applications of Time Domain Electrometry in Geoenvironmental Engineering, Taylor & Francis Group, Great Britain, 2006.

34. Robinson, D. A., S. B. Jones, J. M. Wraith, D. Or, and S. P. Friedman, "A review of advances in dielectric and electrical conductivity measurement in soils using time domain reflectometry," Vadose Zone Journal, Vol. 2, No. 4, 444-475, 2003.

35. Chung, C. C. and C. P. Lin, "Apparent dielectric constant and effective frequency of TDR measurements: Influencing factors and comparison," Vadose Zone Journal, Vol. 8, No. 3, 548-556, 2009.
doi:10.2136/vzj2008.0089

36. Robinson, D. A., M. G. Schaap, D. Or, and S. B. Jones, "On the effective measurement frequency of time domain reflectometry in dispersive and nonconductive dielectric materials ," Water Resources Research, Vol. 41, No. 2, W02 007.1-W02 007.9, 2005.
doi:10.1029/2004WR003816

37. Nicolson, A. M., "Forming the fast fourier transform of a step response in time-domain metrology," Electronic Letters, Vol. 9, No. 14, 317-318, 1973.
doi:10.1049/el:19730228

38. Cataldo, A., G. Cannazza, E. De Benedetto, L. Tarricone, and M. Cipressa, "Metrological assessment of TDR performance for moisture evaluation in granular materials," Measurement, Vol. 42, No. 2, 254-263, 2009.
doi:10.1016/j.measurement.2008.06.006

Prof. Andrea Cataldo

Dr. Giuseppe Cannazza

Dr. Egidio De Benedetto

Dr. Nicola Giaquinto