ASTM_G_121_-_98_2015e1.pdf

Designation:G12198(Reapproved 2015)1Standard Practice forPreparation of Contaminated Test Coupons for theEvaluation of Cleaning Agents1This standard is issued under the fixed designation G121;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.1NOTEEditorial changes were made throughout in October 2015.1.Scope1.1 This practice describes the procedure for the preparationof single-and double-sided contaminated metallic test couponsfor the evaluation of cleaning agents.It is applicable for theevaluation of cleaning agents proposed for the cleaning ofoxygen-enriched systems and components.It also is applicableto other systems where contamination is a concern.1.2 Several classes of contaminants most likely to be foundin oxygen-enriched systems and components are identified.However,if the user of this practice has identified contami-nants not included in these classes,such identified contami-nants may be substituted for the preparation of the testcoupons.1.3 Preparation of nonmetallic substrates is not addressed,although similar methodology may be used.Solvent andcleaning agent compatibility with the nonmetallic substrateshould be verified prior to the preparation of the test coupons.Typical nonmetallic materials utilized in oxygen systems arecontained in Guide G63.1.4 This practice may involve hazardous materials,operations,and equipment.This practice does not purport toaddress all of the safety concerns associated with its use.It isthe responsibility of whomever uses this practice to consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE1235 Test Method for Gravimetric Determination of Non-volatile Residue(NVR)in Environmentally ControlledAreas for SpacecraftF303 Practices for Sampling for Particles in AerospaceFluids and ComponentsF312 Test Methods for Microscopical Sizing and CountingParticles from Aerospace Fluids on Membrane FiltersF324 Test Method for Nonvolatile Residue of VolatileCleaning Solvents Using the Solvent Purity Meter(With-drawn 1987)3F331 Test Method for Nonvolatile Residue of Solvent Ex-tract from Aerospace Components(Using Flash Evapora-tor)G63 Guide for Evaluating Nonmetallic Materials for Oxy-gen ServiceG94 Guide for Evaluating Metals for Oxygen Service2.2 ANSI:B 46.1 Surface Texture(Surface Roughness,Waviness,andLay)3.Terminology3.1 Definitions:3.1.1 contaminant,nunwanted molecular and particulatematter that could affect or degrade the performance of thecomponents upon which they reside.3.1.2 contamination,na process of contaminating.3.1.3 surface roughness,Ra,nthe arithmetic average de-viation of the surface profile from the centerline,normallyreported in micrometres.3.1.4 nonvolatile residue(NVR),nresidual molecular andparticulate matter remaining following the filtration of asolvent containing contaminants and evaporation of the solventat a specified temperature.3.1.5 particle(particulate contaminant),na piece of mat-ter in a solid state with observable length,width,and thickness.3.1.5.1 DiscussionThe size of a particle is usually definedby its great dimension and is specified in micrometres.1This practice is under the jurisdiction of ASTM Committee G04 on Compat-ibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and is thedirect responsibility of Subcommittee G04.02 on Recommended Practices.Current edition approved Sept.1,2004.Published October 2015.Originallyapproved in 1993.Last previous edition approved in 2010 as G121 98(2010)1.DOI:10.1520/G0121-98R15E01.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.6 molecularcontaminant(nonparticulatecontamination),nthe molecular contaminant may be in agaseous,liquid,or solid state.3.1.6.1 DiscussionIt may be uniformly or nonuniformlydistributed,or be in the form of droplets.Molecular contami-nants account for most of the NVR.3.1.7 blank,nthe contamination level of the fluid whenthe test coupon is omitted.3.1.7.1 DiscussionSometimes referred to as“background”level.3.1.8 control coupon(witness coupon),na coupon madefrom the same material as the test coupons,but in this testmethod is not coated with the contaminant.4.Summary of Practice4.1 A solution of the contaminant is applied to either oneside or both sides of the precleaned test coupons and driedunder sta