1、Methods forSampling andAnalyzing GasesfromWelding andAllied ProcessesAWS F1.5M:2003An American National Standard550 N.W. LeJeune Road, Miami, Florida 33126AWS F1.5M:2003An American National StandardApproved byAmerican National Standards InstituteJune 4, 2003Methods for Samplingand Analyzing Gases fr
2、omWelding and Allied ProcessesSupersedes ANSI/AWS F1.5-96Prepared byAWS Project Committee on Fumes and GasesUnder the Direction ofAWS Safety and Health CommitteeApproved byAWS Board of DirectorsAbstractThis standard contains recommended sampling methods and analytical techniques for ozone, carbon mo
3、noxide, nitricoxide, nitrogen dioxide, and gaseous fluoride in welding environments. It complements AWS F1.1, Methods forSampling Airborne Particulates Generated by Welding and Allied Processes.Key WordsWelding gases, air sampling, analytical methods, ozone, carbon monoxide, nitric oxide, nitrogen d
4、ioxide, fluorideStatement on Use of AWS American National StandardsAll standards (codes, specifications, recommended practices, methods, classifications, and guides) of the AmericanWelding Society (AWS) are voluntary consensus standards that have been developed in accordance with the rules of theAme
5、rican National Standards Institute (ANSI). When AWS standards are either incorporated in, or made part of,documents that are included in federal or state laws and regulations, or the regulations of other governmental bodies,their provisions carry the full legal authority of the statute. In such case
6、s, any changes in those AWS standards must beapproved by the governmental body having statutory jurisdiction before they can become a part of those laws andregulations. In all cases, these standards carry the full legal authority of the contract or other document that invokes theAWS standards. Where
7、 this contractual relationship exists, changes in or deviations from requirements of an AWSstandard must be by agreement between the contracting parties.International Standard Book Number: 0-87171-716-6American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126 2003 by American Welding Society.
8、 All rights reservedPrinted in the United States of AmericaAWS American National Standards are developed through a consensus standards development process that bringstogether volunteers representing varied viewpoints and interests to achieve consensus. While AWS administers the processand establishe
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10、e whatsoever, whether spe-cial, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on thisstandard. AWS also makes no guaranty or warranty as to the accuracy or completeness of any information published herein.In issuing and making thi
11、s standard available, AWS is not undertaking to render professional or other services for or onbehalf of any person or entity. Nor is AWS undertaking to perform any duty owed by any person or entity to someoneelse. Anyone using these documents should rely on his or her own independent judgment or, a
12、s appropriate, seek the adviceof a competent professional in determining the exercise of reasonable care in any given circumstances.This standard may be superseded by the issuance of new editions. Users should ensure that they have the latest edition.Publication of this standard does not authorize i
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14、ted incorrectly, constituting errata. Such errata, when discovered, are postedon the AWS web page (www.aws.org).Official interpretations of any of the technical requirements of this standard may be obtained by sending a request, in writing,to the Managing Director, Technical Services Division, Ameri
15、can Welding Society, 550 N.W. LeJeune Road, Miami, FL33126 (see Annex G). With regard to technical inquiries made concerning AWS standards, oral opinions on AWS standardsmay be rendered. However, such opinions represent only the personal opinions of the particular individuals giving them.These indiv
16、iduals do not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or inter-pretations of AWS. In addition, oral opinions are informal and should not be used as a substitute for an official interpretation.This standard is subject to revision at any time by th
17、e AWS Safety and Health Committee. It must be reviewed every fiveyears, and if not revised, it must be either reapproved or withdrawn. Comments (recommendations, additions, ordeletions) and any pertinent data that may be of use in improving this standard are required and should be addressed toAWS He
18、adquarters. Such comments will receive careful consideration by the AWS Safety and Health Committee andthe author of the comments will be informed of the Committees response to the comments. Guests are invited to attendall meetings of the AWS Safety and Health Committee to express their comments ver
19、bally. Procedures for appeal ofan adverse decision concerning all such comments are provided in the Rules of Operation of the Technical ActivitiesCommittee. A copy of these Rules can be obtained from the American Welding Society, 550 N.W. LeJeune Road,Miami, FL 33126.Photocopy RightsAuthorization to
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21、, Danvers, MA 01923, Tel: 978-750-8400;online: http:/.iiiPersonnelAWS Safety and Health CommitteeS. R. Fiore, Chair Edison Welding InstituteR. J. Tucker, 1st Vice Chair Dalloz SafetyS. P. Hedrick, Secretary American Welding SocietyJ. M. Antonini NIOSHK. Bancroft ConsultantK. L. Brown The Lincoln Ele
22、ctric CompanyD. E. Clark Idaho National Engineering LaboratoryC. W. Duffield U.S. Geological SurveyJ. D. Jennings Miller Electric Manufacturing CompanyS. F. Kane Brookhaven National LaboratoryK. A. Lyttle Praxair, IncorporatedA. F. Manz A. F. Manz Associates*O. J. Fisher Consultant*J. F. Hinrichs Fr
23、iction Stir Link, Incorporated*M. T. Neu Caterpillar, Incorporated*R. J. Simonton Sandia National Laboratories*D. H. Sliney U.S. Army Center*R. M. Tuggle U.S. Department of Energy*M. E. Wallace U.S. Public Health ServiceAWS Subcommittee on Fumes and GasesD. E. Clark, Chair Idaho National Engineering
24、 LaboratoryS. R. Fiore, Vice Chair Edison Welding InstituteS. P. Hedrick, Secretary American Welding SocietyK. L. Brown The Lincoln Electric CompanyJ. W. Dimler JWD AssociatesS. R. Jana ESABK. A. Lyttle Praxair, IncorporatedJ. J. Palach Hobart Brothers of CanadaR. B. Smith Select-ArcA. M. Zhivov Zhi
25、vov these instruments canincorporate alarms which can be set at predeterminedlevels.4.4 Detector Tubes and Passive Samplers (see Annex A).Detector tubes consist of sealed glass tubes containing asorbent (such as silica gel which has been impregnatedwith a reagent). When a specific contaminant is pre
26、sentin the air being drawn through the tube, a chemical reac-tion takes place that results in a color change. The con-centration of a contaminant present in a fixed volume ofair yields a given length of stain. The accuracy and repro-ducibility of the method is highly variable. Factors suchas cross s
27、ensitivity (interferences), packing of the re-agent, air flow patterns through the reagent, actual airvolume, and sampling rate can affect the final reading.Precision, accuracy, and reproducibility vary with theage, the conditions of storage, and the lot-to-lot manufac-turing variability of these tu
28、bes. Despite the disadvan-tages, detector tubes do provide a convenient method forpreliminary screening. Where high precision is not criti-cal, they can be used to measure concentrations overshort periods. Using special sampling and statisticaltechniques, short-term tubes can be used to estimate the
29、average concentration over extended periods.An alternative to this approximation technique is theuse of long-term detector tubes that are used in one oftwo ways: in conjunction with personal sampling pumpsor as direct reading passive samplers which require nopump (see Figure 2). Either the short-ter
30、m or long-termmethod properly applied may be used for determiningthe eight-hour, time-weighted average concentration asdefined in AWS Fl.3, Evaluating Contaminants in theWelding Environment: A Sampling Strategy Guide.Figure 1Detector TubeAWS F1.5M:200334.5 Chemical Methods. Chemical methods involve
31、asolid or liquid sorbent through which air is passed at aknown flow rate. The sampling period is determined bythe sensitivity of the method being used and the antici-pated concentration of the contaminant. Some chemicalmethods may involve relatively short sampling periods.Average contaminant concent
32、rations over longer periodsof time can be obtained by taking an adequate number ofshorter period samples throughout the work period.Methods requiring long sampling periods cannot be usedto measure peak or ceiling concentrations. However,these longer test periods can be used to give time-weighted ave
33、rage (TWA) concentrations.4.6 Interferences. In selecting a method to be used, spe-cial attention shall be paid to the presence of positive ornegative interferences, as identified by the manufacturerof the system.4.7 Calibration. Calibration of all methods is necessaryto obtain accurate results. The
34、 calibration shall includeairflow, selectivity, and quantitative response to interfer-ences. The analytical system shall be calibrated by chem-ical reference methods such as the NIOSH methods orwith standard gas mixtures which are certified to give aspecified accuracy over the shelf life of the gas
35、standard.5. Basic Requirements for Sampling5.1 General. The sampling procedure selected shallcause the least interference with the welders jobperformance, provide a representative sample of thebreathing zone and background atmosphere, and be com-patible with subsequent methods of analysis. A blanksa
36、mple is also required for chemical procedures (see theNIOSH Manual of Analytical Methods for additionaldetails).5.2 Sampling Periods. The sampling period for the indi-vidual determination of a contaminant is largely deter-mined by the expected airborne concentration andanalytical method adopted. Wit
37、h short-term detectortubes and some chemical methods, a single determina-tion can be completed within 1 or 2 minutes. Otherchemical methods or passive samplers require longerperiods ranging from 20 minutes to several hours.Instrumental methods usually give instantaneousreadings of concentrations, bu
38、t also can be used to pro-duce a continuous record which can be integrated to givean average concentration over a long time period. Thesampling strategy to be used with gases would be similarto that proposed in AWS F1.3.5.3 Breathing-Zone Sampling. The sampling deviceshall be positioned under the we
39、lding helmet if worn,and approximately 50 mm from the centerline of thebreathing zone at mouth level. Refer to AWS F1.1,Method for Sampling Airborne Particulates Generatedby Welding and Allied Processes.5.4 Static Background Sampling. Normally, the highestconcentration of gases will occur in the imm
40、ediate vicin-ity of the welder (with the possible exception of ozonesee 6.1). On occasion, it may be necessary to sample atanother location in the welding shop (e.g., at adjacentwork operations or within an overhead crane cab). In thiscase, the sampling equipment used shall be similar tothat used fo
41、r the breathing-zone samples. The location ofthe sampling point will be determined by the particularinformation being sought.5.5 Sample Filtration. Particulate fluorides in the sam-ple stream will affect the analytical result for gaseousfluorides, so it is necessary that the air be filtered beforeit
42、 is introduced into the analytical equipment. The filterand holder shall neither affect nor be affected by thematerial being sampled.Some portable direct-reading instruments may incor-porate internal filters. These filters shall be correctlymaintained in order to assure accurate determinations.5.6 S
43、ampling Materials. All sampling lines, filters, stor-age containers, or other apparatus which the sampledatmosphere may contact before its introduction to theFigure 2 Passive Sampler or MonitorAWS F1.5M:20034analytical system shall be made of materials that are inertto the gases being sampled. Stand
44、ard laboratory tubinghas been found acceptable as sampling lines for mostgases except ozone. In the case of ozone, clean sectionsof Bev-A-Line IV3or polytetrafluoroethylene (PTFE)tubing have been found to be acceptable.5.7 Sampling Pump and Rate. The air samples shall bedrawn into the analytical dev
45、ice or sampler at a rate com-patible with the analytical method. The sampling rateshall not vary more than 5%. Short-term detector tubesand some other methods require hand-operated pumps.These pumps shall be calibrated in accordance with themanufacturers procedure. Only the pump recommendedby the de
46、tector tube manufacturer shall be used. A typi-cal sampling pump and filter are shown in Figure 3.A mechanical pump used with methods that require aspecific sample volume or a precise sampling rate shallbe calibrated using the soap bubble method. If the flow ispulsation-free, a calibrated rotameter
47、or other device canbe used. The flow rate shall be checked periodically dur-ing the sampling period.Instrumental methods which incorporate an integralpumping system shall be used and calibrated in accord-ance with the manufacturers instructions.3.Bev-A-Line IV is a registered trademark of Cole-Parme
48、rInstrument Co., Chicago, IL.Note: Concentrations given in parentheses after eachgas represent the working range of interest for each gas.The ranges will be indicated in parts of gas contaminantper million parts of air by volume (ppm). Ranges for gas-eous fluorides will be calculated in milligrams p
49、er cubicmeter (mg/m3).6. Ozone (0.01 ppm1 ppm)6.1 Sampling. Ozone can be generated when ultraviolet(UV) radiation reacts with the surrounding air. Ozone isproduced at the welding arc and in areas remote from thearc. It may, therefore, also be appropriate to sample forozone away from the immediate vicinity of the welder.Because of the reactivity of ozone, the sampling tubes,filters, filter holders, and other items which may come incontact with the air sample before it enters the analyticalsystem shall be made of non-reactive materials. Poly-tetrafluoroethylene (PT
