ASTM_D_6273_-_20.pdf

Designation:D627320Standard Test Method forNatural Gas Odor Intensity1This standard is issued under the fixed designation D6273;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 test method covers the procedures for determiningthe threshold detection level,readily detectable level,and odorintensity of natural gas using instruments that dilute and mixthe sampled natural gas with air.The mixed gas stream is thensniffed by the operator for the purpose of determining any ofthese parameters for odorant in a natural gas stream.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3 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:2D4150 Terminology Relating to Gaseous FuelsD5287 Practice for Automatic Sampling of Gaseous FuelsE253 Terminology Relating to Sensory Evaluation of Mate-rials and Products2.2 Other Standard:349 CFR Part 192.625 Odorization of Gas3.Terminology3.1 For definitions of general terms used in D03 GaseousFuels standards,refer to Terminology D4150.3.2 For definitions of common usage sensory evaluation ofmaterials and products,refer to Terminology E253.3.3 Definitions of Terms Specific to This Standard:3.3.1 high pressure,nfor the purpose of this test method,high pressure refers to natural gas pressure greater than themaximum inlet pressure specified by the manufacturer of thegas dilution apparatus.3.3.2 intensity,nthe magnitude of odor perceived by theoperator.3.3.3 low pressure,nfor the purpose of this test method,low pressure refers to natural gas pressure less than or equal tothe maximum inlet pressure specified by the manufacturer ofthe gas dilution apparatus.3.3.4 olfactory fatigue,ndesensitization of the sense ofsmell through either prolonged exposure or repeated exposureover a short period of time to an odor,a mixture of odors,or aseries of odors.3.3.5 operator(s),nthe person(s)performing the testingdescribed in this test method.3.3.6 readily detectable level,nthe concentration of natu-ral gas and odorant mixture in air at which the operator is ableto detect and identify natural gas odor.3.3.7 sniff,vsmell or snuff with short,audible inhalations.3.3.8 threshold detection level,nthe concentration ofnatural gas and odorant mixture in air at which the operator isbarely able to detect an odor.4.Significance and Use4.1 Federal regulations(49 CFR Part 192.625)state:“Acombustible gas in a distribution line must contain a naturalodorant or be odorized so that at a concentration in air ofone-fifth of the lower explosive limit,the gas is readilydetectable by a person with a normal sense of smell.”Theseregulations state further that“To assure the proper concentra-tion of odorant with this section,each operator must conductperiodic sampling of combustible gases using an instrumentcapable of determining the percentage of gas in air at which theodor becomes readily detectable.”Additionally,a number ofstates have enacted legislation that requires natural gas to beodorized so that it is detectable at concentrations less than onefifth of the lower explosive limit.See Note 1.While regulations1This test method is under the jurisdiction ofASTM Committee D03 on GaseousFuels and is the direct responsibility of Subcommittee D03.05 on Determination ofSpecial Constituents of Gaseous Fuels.Current edition approved Nov.1,2020.Published November 2020.Originallyapproved in 1998.Last previous edition approved in 2014 as D6273 14.DOI:10.1520/D6273-20.2For 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.3Available from Standardization Documents Order Desk,DODSSP,Bldg.4,SectionD,700RobbinsAve.,Philadelphia,PA19111-5098,http:/www.dodssp.daps.mil.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