ASTM_D_7240_-_18.pdf

Designation:D724018Standard Practice forElectrical Leak Location Using Geomembranes with anInsulating Layer in Intimate Contact with a ConductiveLayer via Electrical Capacitance Technique(Conductive-Backed Geomembrane Spark Test)1This standard is issued under the fixed designation D7240;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice is a performance-based standard for anelectrical method for locating leaks in exposed conductive-backed geomembranes.For clarity,this practice uses the term“leak”to mean holes,punctures,tears,knife cuts,seam defects,cracks,and similar breaches in an installed geomembrane(asdefined in 3.2.7).1.2 This practice can be used for conductive-backedgeomembranes installed in basins,ponds,tanks,ore and wastepads,landfill cells,landfill caps,canals,and other containmentfacilities.It is applicable for conductive-backed geomembranesmade of materials such as polyethylene,polypropylene,poly-vinyl chloride,chlorosulfonated polyethylene,bituminousgeomembrane,and any other electrically insulating materials.This practice is best applicable for locating conductive-backedgeomembrane leaks where the proper preparations have beenmade during the construction of the facility.1.3 For electrical leak location of conductive-backedgeomembranes using methods in lieu of or in addition to thespark testing method,the installation must be electricallyisolated(as defined in 3.2.5).1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 The spark test may produce an electrical spark andtherefore should only be used where an electrical spark wouldnot create a hazard.This standard does not purport to addressall of the safety concerns,if any,associated with its use.It isthe responsibility of the user of this standard to establishappropriate safety,health,and environmental practices anddetermine the applicability of regulatory limitations prior touse.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D4439 Terminology for GeosyntheticsD5641/D5641M Practice for Geomembrane Seam Evalua-tion by Vacuum ChamberD5820 Practice for Pressurized Air Channel Evaluation ofDual Seamed GeomembranesD6747 Guide for Selection of Techniques for Electrical LeakLocation of Leaks in Geomembranes3.Terminology3.1 Definitions:3.1.1 For general definitions used in this practice,refer toTerminology D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 conductive-backed geomembrane,na specialtygeomembrane manufactured using coextrusion technology,featuring an insulating layer in intimate contact with a conduc-tive layer.3.2.2 coupling pad,nan electrically conductive padplaced on top of the geomembrane and connected to the sparktesting apparatus used to induce electrical potential across theconductive-backed geomembrane.3.2.3 current,nthe flow of electricity or the flow ofelectric charge.3.2.4 electrical leak location,na method which useselectrical current or electrical potential to locate leaks in ageomembrane.1This practice is under the jurisdiction of ASTM Committee D35 on Geosyn-thetics and is the direct responsibility of Subcommittee D35.10 on Geomembranes.Current edition approved Feb.1,2018.Published February 2018.Originallypublished in 2006.Last previous edition approved 2011 as D7240 06(2011).DOI:10.1520/D7240-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 3.2.5 electrically isolated conductive-backed geomembraneinstallation,nan installation of conductive-backed geomem-brane that achieves a continuously conductive surface on thebottom layer,while electrically isolating the bottom conductivelayer from the top insulating layer of the entire geomembraneinstallation.3.2.6 false positive,nan alarm or spark,or both,generatedby the spark testing equipment on a feature that is not an actualbrea