ASTM_E_2520_-_15.pdf

Designation:E252015Standard Practice forMeasuring and Scoring Performance of Trace ExplosiveChemical Detectors1This standard is issued under the fixed designation E2520;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 may be used for measuring,scoring,andimproving the overall performance of detectors that alarm ontraces of explosives on swabs.These explosive trace detectors(ETDs)may be based on,but are not limited to,chemicaldetection technologies such as ion mobility spectrometry(IMS)and mass spectrometry(MS).Technologies that usethermodynamic or optical detection are not specificallyaddressed,but may be adapted into future versions of thispractice.1.2 This practice considers instrumental(post-sampling)trace detection performance,involving specific chemical ana-lytes across eight types of explosive formulations in thepresence of a standard background challenge material.Thispractice adapts Test Method E2677 for the evaluation of limitof detection,a combined metric of measurement sensitivity andrepeatability,which requires ETDs to have numerical re-sponses.1.3 This practice considers the effective detection through-put of an ETD by factoring in the sampling rate,interrogatedswab area,and estimated maintenance requirements during atypical eight hour shift.1.4 This practice does not require,but places extra value on,the specific identification of targeted compounds and explosiveformulations.1.5 This practice requires the use of a single set of ETDoperational settings for calculating a system test score based onthe factors described in 1.2,1.3,and 1.4.A minimum accept-able score is derived from criteria established in PracticeE2520 07.1.6 Intended UsersETD developers and manufacturers,testing laboratories,and international agencies responsible forenabling effective deterrents to terrorism.1.7 Actual explosives as test samples would be preferable,but standard explosive formulations are not widely available,nor are methods for depositing these quantitatively and realis-tically on swabs.This practice considers sixteen compoundsthat are available from commercial suppliers.This does notimply that only these sixteen are important to trace detection.Most ETDs are able to detect many other compounds,but theseare either chemically similar(hence redundant)to the onesconsidered,or are unavailable from commercial suppliers forreasons of stability and safety.Under typical laboratorypractices,the sixteen compounds considered are safe to handlein the quantities used.1.8 This practice is not intended to replace any currentstandard procedure employed by agencies to test performanceof ETDs for specific applications.Those procedures may bemore rigorous,use different compounds or actual explosiveformulations,employ different or more realistic backgroundchallenges,and consider environmental sampling proceduresand other operational variables.1.9 This practice recommends one method for preparationof test swabs,pipetting,because this method is simple,reproducible,quantitative,documented,and applicable to mostcurrent detection technologies.Other methods,such as inkjetprinting and dry transfer,may generate more realistic analytedistributions and particle sizes,but these methods are notwidely available and less familiar.They may be used if theprocedures are validated and documented properly.1.10 With any deposition method,some compounds aredifficult to present to the ETD inlet quantitatively due tovolatility and loss during the swab preparation process.Prob-lematic issues pertinent to this practice are identified alongwith recommended instructions.The user should be aware ofthe possibility that untested scenarios may lead to failure in thedetermination of reliable test scores.1This practice is under the jurisdiction of ASTM Committee E54 on HomelandSecurity Applications and is the direct responsibility of Subcommittee E54.01 onCBRNE Sensors and Detectors.Current edition approved Feb.1,2015.Published February 2015.Originallyapproved in 2007.Last previous edition approved in 2007 as E2520 07.DOI:10.1520/E2520-15.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 1.11 UnitsThe values stated in SI units are to be regardedas standard.No other units of measurement are included in thisstandard.1.12 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E1154 Specification for Piston or Plunger Operated Volu-metric ApparatusE2677 Test Method for Determining Limits