1、Designation: D6831 11 (Reapproved 2018)Standard Test Method forSampling and Determining Particulate Matter in Stack GasesUsing an In-Stack, Inertial Microbalance1This standard is issued under the fixed designation D6831; the number immediately following the designation indicates the year oforiginal
2、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 describes the procedures for determin-ing the mass
3、concentration of particulate matter in gaseousstreams using an automated, in-stack test method. This testmethod, an in-situ, inertial microbalance, is based on inertialmass measurement using a hollow tube oscillator. This testmethod is describes the design of the apparatus, operatingprocedure, and t
4、he quality control procedures required toobtain the levels of precision and accuracy stated.1.2 This test method is suitable for collecting and measuringfilterable particulate matter concentrations in the ranges 0.2mg/m3and above taken in effluent ducts and stacks.1.3 This test method may be used fo
5、r calibration of auto-mated monitoring systems (AMS). If the emission gas containsunstable, reactive, or semi-volatile substances, the measure-ment will depend on the filtration temperature, and this testmethod (and other in-stack methods) may be more applicablethan out-stack methods for the calibra
6、tion of automated moni-toring systems.1.4 This test method can be employed in sources having gastemperature up to 200C (392F) and having gas velocitiesfrom 3 to 27 m/s.1.5 This test method includes a description of equipmentand methods to be used for obtaining and analyzing samplesand a description
7、of the procedure used for calculating theresults.1.6 This test method may also be limited from use insampling gas streams that contain fluoride, or other reactivespecies having the potential to react with or within the sampletrain.1.7 Appendix X1 provides procedures for assessment of thespatial vari
8、ation in particulate matter (PM) concentrationwithin the cross section of a stack or duct test location todetermine whether a particular sampling point or limitednumber of sampling points can be used to acquire representa-tive PM samples.1.8 Appendix X2 provides procedures for reducing thesampling t
9、ime required to perform calibrations of automatedmonitoring systems where representative PM samples can beacquired from a single sample point and certain other condi-tions are met.1.9 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconvers
10、ions to inch-pound units that are provided for informa-tion only and are not considered standard.1.10 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, a
11、nd environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.11 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of Internationa
12、l Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD3154 Test Method for Average Velocity in a Duct (PitotTube Method)D3
13、685/D3685M Test Methods for Sampling and Determina-tion of Particulate Matter in Stack GasesD3796 Practice for Calibration of Type S Pitot TubesD6331 Test Method for Determination of Mass Concentra-tion of Particulate Matter from Stationary Sources at LowConcentrations (Manual Gravimetric Method)1Th
14、is test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved April 15, 2018. Published May 2018. Originallyapproved in 2002. Last previous edition approved in 2
15、011 as D6831 11. DOI:10.1520/D6831-11R18.2For 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.Copyright ASTM Inter
16、national, 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,
17、Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.12.2 EPA Methods from 40 CFR Part 60, Appendix A:Method 3A Determination of Oxygen and Carbon DioxideConcentrations in Emissions from Stationary Sources(Instrumental Analyzer Procedure)Metho
18、d 5 Determination of Particulate Emissions from Sta-tionary SourcesMethod 17 Determination of Particulate Emissions fromStationary Sources (In-Situ Filtration Method)2.3 EPA Methods from 40 CFR Part 60, Appendix B:Performance Specification 11 Specifications and Test Proce-dures for Particulate Matte
19、r Continuous Emission Moni-toring Systems at Stationary Sources2.4 EPA Methods from 40 CFR Part 63, Appendix A:Method 301 Field Validation of Pollutant MeasurementMethods from Various Waste Media3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology D1356.3.2 Defini
20、tions of Terms Specific to This Standard:3.2.1 particulate mattersolid or liquid particles of anyshape, structure, or density (other than water) dispersed in thegas phase at flue gas temperature and pressure conditions.3.2.1.1 DiscussionIn accordance with the described testmethod, all material that
21、may be collected by filtration underspecified conditions and that remains upstream of the filter andon the filter after drying under specified conditions are consid-ered to be particulate matter. For the purposes of this testmethod, particulate matter is defined by gas borne matter (solidor liquid)
22、captured on or in the filter after drying and weighingin accordance with this test method.3.2.2 in-stack, inertial microbalancea mechanical oscilla-tor constructed of a hollow tube of a specific metal alloy andfitted with a filter cartridge that is designed to oscillate at afrequency that is proport
23、ional to the mass of the hollow tubeoscillator plus the mass of its filter cartridge.3.2.3 mass transducerthe mass transducer is a principlecomponent of an in-stack inertial, microbalance. The masstransducer provides the mechanical structure to support andcontain the hollow tube oscillator and to su
24、pport the sampleinlet nozzle fixture, source gas temperature thermocouple, andS-type Pitot tube assembly. Refer to 6.1.1 for a detaileddescription of this component.3.2.4 articulating elbowa mechanical component thatmay be integrated into the sample probe just before the endconnector attaching to th
25、e mass transducer. This elbow is usedcontrol the angle of the mass transducer relative to the sampleprobe during insertion of the probe and mass transducer intothe stack and while positioning the mass transducer inlet nozzleinto the gas stream.3.2.5 filtration temperaturethe temperature of the sampl
26、edgas immediately downstream of the filter cartridge.3.2.5.1 DiscussionThe temperature of the filter cartridgeis maintained at the desired temperature by controlling thetemperature of the mass transducer case and cap.3.2.6 sampling linethe line in the sampling plane alongwhich the sampling points ar
27、e located bounded by the innerduct wall.3.2.7 sampling planethe plane normal to the centerline ofthe duct at the sampling position.3.2.8 sampling pointthe specific position on a samplingline at which a sample is extracted.3.2.9 weighing control proceduresquality control proce-dures used for verifyin
28、g the calibration constant for the hollowtube oscillator.3.2.9.1 DiscussionUnlike test methods such as D6331 orD3685/D3685M, this test method does not rely on weighingsample media in a laboratory before and after a test isconducted. The method includes an integrated filter dryingmechanism to desicca
29、te the sample collection media in-situimmediately prior to and following each test run. No physicalhandling of sample collection media takes place prior to thestart of a test run through final filter analysis for the test run.Consequently, control filters typically used to characterize theimpact of
30、filter/sample handling and transportation are notrequired with this test method.4. Summary of Test Method4.1 The in-stack, inertial microbalance method involves theuse of a filter cartridge affixed at one end of a hollow tubeoscillator that is housed in a mass transducer housing. Themass transducer
31、is attached to the end of an integrated sampleprobe and inserted through a port into the stack or duct. Asample is withdrawn isokinetically from the gas stream anddirected through the filter cartridge attached to the end of thehollow tube oscillator. Captured particulate matter and anycaptured moist
32、ure is weighed continuously as the sample gasespass through the filter cartridge and hollow tube oscillator.Sample gases then continue through the heated probe andumbilical assemblies and into a gas conditioning/control mod-ule where the collected gas sample volume is determined. Acalibrated, orific
33、e-based flow meter is used to measure thesample gas volume. In sources where the particulate mattercharacteristics can result in significant quantity of particulatematter to be trapped on the inlet nozzle walls during sampling,the trapped particulate matter can be recovered after samplinghas been co
34、mpleted using a properly sized brush to detach andrecover trapped particulate matter from the inlet walls.4.1.1 DiscussionThe ability of this mass measurementtechnique to precisely quantify the mass of the filter andcollected particulate matter by correlating mass change to ameasured frequency chang
35、e of the hollow tube oscillator ispredicated on the isolation of the oscillator from externalvibration sources. To remove the potential for external vibra-tion to interfere with the measurement process, the masstransducer housing must be sufficiently massive so that anyenergy that it absorbs from ex
36、ternal vibrations will result in themass transducer case oscillating at a resonant frequency that ismuch lower the hollow tube oscillator. As a result, a massivehousing will absorb any external vibrations and prevent thosevibrations from affecting the resonance of the hollow tubeoscillator.D6831 11
37、(2018)24.2 The filter media typically used is PTFE coated glassfiber filter media (TX-40 or equivalent) although other filtermedia can be used if desired. The filter media is mounted in aspecially designed filter cartridge housing that is designed topromote a constant face velocity through the entir
38、e surface ofthe filter. The junction of the oscillating element and the baseof the filter cartridge is designed to ensure a leak free union.4.3 The sample gases are dried using a selectively perme-able membrane dryer followed by silica gel before the samplevolume is measured. An integrated computer-
39、controlled feed-back system is used to control the sample flow rate based onstack gas temperature, velocity and gas density measurements,or user input data, to automatically maintain isokinetic sam-pling conditions.4.4 To account for source gas density (molecular weight)inputs to set the isokinetic
40、sampling conditions, the user has theoption to use manually input data acquired using an Orsatanalyzer and moisture determination apparatus, or equivalentmethods, or data supplied by an on-board carbon dioxideanalyzer, oxygen analyzer and moisture measurement system.4.5 Valid measurements can be ach
41、ieved when:4.5.1 The gas stream in the duct at the sampling plane has asufficiently steady and identified velocity, a sufficient tempera-ture and pressure, and a sufficiently homogeneous composi-tion;4.5.2 The flow of the gas is parallel to the centerline of theduct across the whole sampling plane;4
42、.5.3 Sampling is carried out without disturbance of the gasstream, using a sharp edged nozzle facing into the stream;4.5.4 Isokinetic sampling conditions are maintainedthroughout the test within 610 %;4.5.5 Samples are taken at a pre-selected number of statedpositions in the sampling plane to obtain
43、 a representativesample for a non-uniform distribution of particulate matter inthe duct or stack.4.5.6 The sampling train is designed and operated to avoidcondensation and to be leak free;4.5.7 Dust deposits upstream of the filter are recovered ortaken into account, or both; and4.5.8 The sampling an
44、d weighing procedures include desic-cation of the filter immediately before and after each test run isconducted.5. Significance and Use5.1 The measurement of particulate matter is widely per-formed to characterize emissions from stationary sources interms of emission concentrations and emission rate
45、s to theatmosphere for engineering and regulatory purposes.5.2 This test method provides near real-time measurementresults and is particularly well suited for use in performanceassessment and optimization of particulate matter controlsachieved by air pollution control devices or process modifica-tio
46、ns (including fuel, feed, or process operational changes) andperformance assessments of particulate matter continuousemissions monitoring systems (PM CEMS)5.3 This test method is well suited for measurement ofparticulate matter-laden gas streams in the range of 0.2 mg/m3to 50 mg/m3, especially at lo
47、w concentrations.5.4 The U.S. EPA has concurred that this test method hasbeen demonstrated to meet the Method 301 bias3and precisioncriteria for measuring particulate matter from coal fired utilityboilers when compared with EPA Method 17 and Method 5(40CFR60, Appendix A).5.5 This test method can acc
48、urately measure relative par-ticulate matter concentrations over short intervals and can beused to assess the uniformity of particulate concentrations atvarious points on a measurement traverse within a duct orstack.6. System Description6.1 Major ComponentsThe in-stack, inertial microbalancemeasurem
49、ent system is comprised of five major componentsthat are listed in the following table.Mass Transducer(see 6.1.1)An assembly that houses the sample filter and inertialmicrobalance. Also contains the Pitot tube assembly,stack gas temperature thermocouple, sample inletnozzle and mass transducer heaters.Sample Probe andProbe Extensions(see 6.1.2)A heated support conduit for mass transducer, sample andpurge flow lines; electrical supplies for mass transducerand probe heaters; mass transducer electrical signalcables; and the pivoting elbow used for positioning themass tra
