Commercial leak‐noise correlators were generally able to locate leaks in plastic pipe, but modifications could increase their effectiveness. Water utilities commonly use acoustic equipment to locate leaks. Although acoustic equipment is generally considered satisfactory for metallic pipes, its application to plastic pipes could be problematic. This study found that leaks in plastic pipes could be located using acoustic techniques; however, there were several difficulties. Professional leak detection teams using leak noise correlators rarely succeeded in locating leaks because the frequency range selected automatically by correlators (or manually by operators) was usually too high. The frequency content of leak signals from plastic pipes was mostly below 50 Hz. Listening devices were ineffective unless they were used very close to leaks. Acoustic leak detection methods can be made more effective by revising the automatic‐mode algorithms of correlators, using finely tunable noise filters, and measuring leak signals with hydrophones or highly sensitive vibration sensors. Nonacoustic methods such as radar, thermography, and tracer gases, appear promising.

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1016/S0003-682X(99) Applied Acoustics, 58, 3, pp. 235-254, 1999-07-01 Acoustical characteristics of leak signals in plastic water distribution pipes Hunaidi, O.; Chu, W. T. Acoustical Characteristics of Leak Signals in Plastic Water Distribution Pipes

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Abstract:Extensive measurements and detailed analysis of building vibration induced by road traffic in Montréal were carried out for nine representative complaint sites. Vibration levels were evaluated with reference to human annoyance and the potential for building damage using existing standards. The effects of road condition and seasonal variations in soil conditions on vibration levels were also investigated using vibration measurements before and after a road was resurfaced and at different seasons. Details of test methods, measurement and analysis procedures, and the major findings of the study are presented in this paper.Key words: vibrations, buildings, road traffic, site response, human annoyance, building damage.Résumé : Une étude détaillée ainsi que des mesures de la vibration de bâtiments causée par la circulation routière à Montréal furent effectuées pour neuf sites représentatifs où des plaintes ont été signalées. Les niveaux de vibration furent évalués en fonction du mécontentement de la population et du potentiel d'endommagement des bâtiments selon les standards existants. La vibration fut mesurée avant et après le repavage de la route et au cours des saisons afin d'étudier l'influence de la condition des routes et des variations saisonnières du sol sur les niveaux de vibration. Les détails sur les méthodes d'essais, les procédures d'analyse et de mesure, ainsi que les principales conclusions de cette étude sont présentées dans cet article.