1、Designation:B82705(Reapproved 2014)Standard Practice forConducting Mixed Flowing Gas(MFG)Environmental Tests1This standard is issued under the fixed designation B827;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last re
2、vision.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 provides procedures for conducting envi-ronmental tests involving exposures to controlled quantities ofcorrosive gas
3、 mixtures.1.2 This practice provides for the required equipment andmethods for gas,temperature,and humidity control whichenable tests to be conducted in a reproducible manner.Repro-ducibility is measured through the use of control couponswhose corrosion films are evaluated by mass gain,coulometry,or
4、 by various electron and X-ray beam analysis techniques.Reproducibility can also be measured by in situ corrosion ratemonitors using electrical resistance or mass/frequency changemethods.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thi
5、sstandard.1.4 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 become familiarwith all hazards including those identified in the appropriateMaterial Safety Data Sheet(MSDS)for this product/mater
6、ialas provided by the manufacturer,to establish appropriatesafety and health practices,and determine the applicability ofregulatory limitations prior to use.See 5.1.2.4.2.Referenced Documents2.1 ASTM Standards:2B542 Terminology Relating to Electrical Contacts and TheirUseB765 Guide for Selection of
7、Porosity and Gross Defect Testsfor Electrodeposits and Related Metallic CoatingsB808 Test Method for Monitoring ofAtmospheric CorrosionChambers by Quartz Crystal MicrobalancesB810 Test Method for Calibration ofAtmospheric CorrosionTest Chambers by Change in Mass of Copper CouponsB825 Test Method for
8、 Coulometric Reduction of SurfaceFilms on Metallic Test SamplesB826 Test Method for Monitoring Atmospheric CorrosionTests by Electrical Resistance ProbesB845 Guide for Mixed Flowing Gas(MFG)Tests for Elec-trical ContactsD1193 Specification for Reagent WaterD2912 Test Method for Oxidant Content of th
9、e Atmosphere(Neutral Ki)(Withdrawn 1990)3D2914 Test Methods for Sulfur Dioxide Content of theAtmosphere(West-Gaeke Method)D3449 Test Method for Sulfur Dioxide in Workplace Atmo-spheres(Barium Perchlorate Method)(Withdrawn 1989)3D3464 Test Method for Average Velocity in a Duct Using aThermal Anemomet
10、erD3609 Practice for Calibration Techniques Using Perme-ation TubesD3824 Test Methods for Continuous Measurement of Ox-ides of Nitrogen in theAmbient or WorkplaceAtmosphereby the Chemiluminescent MethodD4230 Test Method of Measuring Humidity with Cooled-Surface Condensation(Dew-Point)HygrometerE902
11、Practice for Checking the Operating Characteristics ofX-Ray Photoelectron Spectrometers(Withdrawn 2011)3G91 Practice for Monitoring Atmospheric SO2DepositionRate for Atmospheric Corrosivity Evaluation3.Terminology3.1 Definitions relating to electrical contacts are in accor-dance with Terminology B54
12、2.4.Significance and Use4.1 Mixed flowing gas(MFG)tests are used to simulate oramplify exposure to environmental conditions which electricalcontacts or connectors can be expected to experience in variousapplication environments(1,2).41This practice is under the jurisdiction of ASTM Committee B02 on
13、NonferrousMetals and Alloys and is the direct responsibility of Subcommittee B02.11 onElectrical Contact Test Methods.Current edition approved Oct.1,2014.Published October 2014.Originallyapproved in 1992.Last previous edition approved in 2009 as B827 05(2009)2.DOI:10.1520/B0827-05R14.2For referenced
14、 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.o
15、rg.4The boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.2 Test samples which have been exposed to MFG testshave ranged from bare metal surfaces,t
16、o electrical connectors,and to complete assemblies.4.3 The specific test conditions are usually chosen so as tosimulate,in the test laboratory,the effects of certain represen-tative field environments or environmental severity levels onstandard metallic surfaces,such as copper and silver couponsor porous gold platings(1,2).4.4 Because MFG tests are simulations,both the test con-ditions and the degradation reactions(chemical reaction rate,composition of reaction products,etc.)may not always re-se
