1、Designation: D5835 95 (Reapproved 2013)Standard Practice forSampling Stationary Source Emissions for the AutomatedDetermination of Gas Concentrations1This standard is issued under the fixed designation D5835; the number immediately following the designation indicates the year oforiginal adoption or,
2、 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 practice2covers procedures and equipment thatwill permit, within certain li
3、mits, representative sampling forthe automated determination of gas concentrations of effluentgas streams. The application is limited to the determination ofoxygen (O2), carbon dioxide (CO2), carbon monoxide (CO),sulfur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2)and total oxides of nitr
4、ogen (NOx).1.2 Velocity measurements are required to determine themass flow rates of gases. This is not included in this practice.1.3 There are some combustion processes and situations thatmay limit the applicability of this practice. Where suchconditions exist, caution and competent technical judgm
5、ent arerequired, especially when dealing with any of the following:1.3.1 Corrosive or highly reactive components,1.3.2 High vacuum, high pressure, or high temperature gasstreams,1.3.3 Wet flue gases,1.3.4 Fluctuations in velocity, temperature, or concentrationdue to uncontrollable variation in the p
6、rocess,1.3.5 Gas stratification due to the non-mixing of gasstreams,1.3.6 Measurements made using environmental controldevices, and1.3.7 Low levels of gas concentrations.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility
7、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. For more specificsafety precautions, refer to 5.1.4.8, 5.2.1.6, and 6.2.2.1.2. Referenced Documents2.1 ASTM Standards:3D1356 Terminology Relatin
8、g to Sampling and Analysis ofAtmospheresD1608 Test Method for Oxides of Nitrogen in GaseousCombustion Products (Phenol-Disulfonic Acid Proce-dures)D3154 Test Method for Average Velocity in a Duct (PitotTube Method)2.2 Other Document:40 CFR Part 60, Standards of Performance for StationarySources, App
9、endix A, Test Methods 2, 3, 3a, 6, 6c, 7, 7e,and 1043. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this practice, refer toTerminology D1356.4. Summary of Practice4.1 This practice describes representative sampling of gasesin a duct, including both extractive and non-extractive
10、sam-pling. In extractive sampling, these gases are conditioned toremove aerosols, particulate matter, and other interferingsubstances before being conveyed to the instruments. Innon-extractive sampling, the measurements are made in-situ;therefore, no sample conditioning except filtering is required.
11、4.1.1 Extractive SamplingExtractive sampling includesextraction of the sample, removal of interfering materials, andmaintenance of the gas concentration throughout the samplingsystem for subsequent analysis by appropriate instrumentation(see Fig. 1).4.2 Non-extractive SamplingNon-extractive sampling
12、does not involve removal of a sample, and sampling is confinedto the gas stream in the stack or duct (see Figs. 2 and 3).1This practice is under the jurisdiction of ASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheresand Source Emissions.Cur
13、rent edition approved April 1, 2013. Published April 2013. Originallyapproved in 1995. Last previous edition approved in 2007 as D5835 - 95(2007).DOI: 10.1520/D5835-95R13.2This practice is based on ISO 10396, “Stationary source emissionsSamplingfor the automated determination of gas concentrations,”
14、 available from InternationalOrganization for Standardization, Casa Postale 56, CH-1211, Geneva, Switzerland.3For 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 sta
15、ndards Document Summary page onthe ASTM website.4Available from Supt. of Documents, U.S. Government Printing Office,Washington, DC 20402.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Representative Factors5.1 Nature of the Source
16、:5.1.1 The representativeness of the determination of gas-eous concentration in enclosed gas streams depends on severalfactors:5.1.1.1 The heterogeneity of the process stream, such asvariations in concentration, temperature, or velocity across theduct caused by moisture or gas stratification,5.1.1.2
17、 Gas leakage or air infiltration and continuous gasreactions, and5.1.1.3 Random errors due to the finite nature of the sampleand the sampling procedure adopted to obtain a representativesample.5.1.2 Representativeness may be difficult to achieve for thefollowing reasons:5.1.2.1 Nature of the source
18、(for example, cyclic,continuous, or batch),5.1.2.2 Concentration level of the gas,5.1.2.3 Size of the source, and5.1.2.4 Configuration of the duct network where samplesare extracted.5.1.3 Where there are difficulties due to the nature of thesource as noted in 5.1.2, establish the concentration profi
19、le foreach operating condition and to determine the best samplinglocation.5.1.3.1 Some sources may have more variability in process(for example, cyclic variation) and, consequently, any timedependent measurement may be less representative of theaverage concentration if a full cycle of variability is
20、 notsampled.5.1.4 Before any measurements are carried out, it is neces-sary to become familiar with the pertinent operating character-istics of the process from which emissions are to be sampledand determined. These operating characteristics include, butare not necessarily limited to, the following:
21、5.1.4.1 Mode of process operation (cyclic, batch charging,or continuous),5.1.4.2 Process feed rates and composition,5.1.4.3 Fuel rates and composition,5.1.4.4 Normal operating gas temperatures and pressures,5.1.4.5 Operating and removal efficiency of the pollutioncontrol equipment,NOTEKey:1 Baffle 1
22、3 Heater2 In-stack Filter 14 Refrigeration Unit3 Tee 15 Water Discharge4 Probe 16 Vacuum Gage5 Sampling Port 17 Bypass Valve6 Cap 18 Pump7 Pressure Gage 19 Sampling Line (Heating Optional)8 To Zero and Span Gases 20 Manifold9 Heat-traced Sampling Line 21 To Analyzer(s)10 Temperature Controller (Line
23、) 22 Rotameter11 Temperature Controller (Box) 23 Vent12 FilterFIG. 1 Extractive Sampling and Conditioning SystemD5835 95 (2013)25.1.4.6 Configuration of the ducts to be sampled leading togas stratification,5.1.4.7 Volumetric gas flow rates, and5.1.4.8 Expected gas composition and likely interferings
24、ubstances. (WarningExercise caution if the duct to besampled is under pressure or vacuum, or at a high temperature.)5.2 Location:5.2.1 Inspection ParametersPerform an inspection of thephysical characteristics of the test site to evaluate factors suchas:5.2.1.1 Safety of the personnel,5.2.1.2 Locatio
25、n of the flow disturbances,5.2.1.3 Accessibility of the sampling site,5.2.1.4 Available space for the sampling equipment andinstrumentation and possible scaffolding requirements,5.2.1.5 Availability of suitable electrical power, compressedair, water, steam, etc., and5.2.1.6 Sampling port locations.
26、(WarningUse the elec-trical equipment in accordance with the local safety require-ments. Where a potentially explosive or hazardous atmosphereis suspected, apply particular attention and precautions toensure the safety of the operations.)5.2.2 Sampling Site Location:5.2.2.1 It is necessary to ensure
27、 that the gas concentrationsmeasured are representative of the average conditions insidethe duct or stack. The requirements for the extractive samplingof gas may be not as stringent as those for particulate material.It is important that the sampling location be removed from anyobstructions that will
28、 seriously disturb the gas flow in the ductor stack. The pollutant can have cross sectional variation. Theconcentration at various points of the cross-section shall first bechecked, in order to assess the homogeneity of the flow and todetect any infiltration of air or gas stratification, etc. If apr
29、eliminary analysis of cross-section at measurements takenindicates more than 6 15 % variation in concentrations, and ifan alternative acceptable location is not available, multi-pointsampling is recommended.5.2.2.2 Multi-point sampling may be achieved either bymoving the probe from point to point or
30、 having a probe withmultiple access ports. Usually, the cross sectional concentra-tion of gaseous pollutants is uniform, because of the diffusionand turbulent mixing. If so, it is only necessary to sample atone point within the stack or duct to determine the averageconcentration. Extract gas samples
31、 near the center of the stacksampling site. When using nonextractive systems, obtain aconcentration as representative as possible, but ensure that theinstrument location is representative.5.3 Gas Concentration, Velocity, and Temperature ProfileBefore commencing sampling, determine if there are anysp
32、atial or temporal fluctuations in the gas concentrations byconducting a preliminary survey of the gas concentration,temperature, and velocity. Measure the concentration,temperature, and velocity at the sampling points several timesto obtain their spatial and temporal profiles. Conduct thissurvey whe
33、n the plant is operating under conditions that will berepresentative of normal operation and determine whether thesampling position is suitable and whether the conditions in theduct are satisfactory (see 5.1.2).5.3.1 The following test methods may be used to determinegas concentration, temperature,
34、and velocity:5.3.1.1 O2Test Method D3154, EPA Test Methods 3 and3a,5.3.1.2 CO2Test Method D3154, EPATest Methods 3 and3a,5.3.1.3 COEPA Test Method 10,5.3.1.4 SO2EPA Test Methods 6 and 6c,5.3.1.5 NOxTest Method D1608, EPATest Methods 7 and7e,5.3.1.6 Gas TemperatureTest Method D3154, EPA TestMethod 2,
35、 and5.3.1.7 Gas VelocityTest Method D3154, EPA TestMethod 2.5.4 Other FactorsThe principle of operation and thecomponents of the instrument systems can significantly affectthe degree to which a collected sample is representative of themeasured gas in the source. For example, a point samplingextracti
36、ve system requires more attention to sampling sitelocation than an across-the-stack in-situ sampling system.Furthermore, sampling lines should not be composed ofmaterials that have gas adsorbing properties that can affect theresponse time of the measurement section (see Table A1.1).5.4.1 Exercise ca
37、re to preserve the integrity of the sampletaken, by a good selection of equipment, and appropriateheating, drying, and leak testing, etc. In addition, other factorsNOTEKey:1 Measurement Cell 6 Data Recorder2 Probe Filter 7 Protective Hood3 Probe 8 Transceiver4 Duct or Stack 9 Probe Mounting5 Gas Cal
38、ibration LineFIG. 2 Non-Extractive Point MonitorD5835 95 (2013)3such as corrosion, synergies, reaction with components,decomposition, and adsorption might affect the integrity of asample.6. Equipment6.1 Recommended construction materials are described inAnnex A1.6.2 Components of Extractive Sampling
39、 Equipment:6.2.1 Primary FilterThe filter medium shall be con-structed of an appropriate alloy (such as a specific stainlesssteel cast alloy), quartz borosilicate, ceramics, or anothersuitable material. A filter that retains particles greater than 10m is recommended. A secondary filter might be requ
40、ired aswell (see 6.2.4). The filter medium may be located outside theduct or at the tip of the sample probe (6.2.2). If placed at the tipof the probe, a deflector plate may be added to prevent particlebuild-up on the leading edge of the filter. This will preventblockage of the filter. Avoid contamin
41、ation of the filter withparticulate matter where condensate may react with gases,resulting in erroneous result.6.2.2 Probe:6.2.2.1 Metal ProbesThe choice of the metal dependsbasically on the physical and chemical properties of the sampleand on the nature of the gas to be determined. Mild steel issub
42、ject to corrosion by oxidizing gases and may be porous tohydrogen. Thus, it is preferable to have stainless steel orchromium steels that can be used up to 900C. Other specialsteels or alloys can be used above this temperature. Heat theprobe if condensation occurs in its interior and cool it with ana
43、ir or water jacket when sampling in very hot gases. Electri-cally ground metal probes since high voltages are easilygenerated in dry gas streams, causing particulate matter to becollected on the probe surface. Grounding is particularlyimportant when employed in an explosive atmosphere.6.2.2.2 Refrac
44、tory Probes (see Annex A1), generally madeof vitreous silica, porcelain, mullite or recrystallized alumina.They are fragile and may warp at high temperatures; with theexception of silica, they may also crack from thermal shock.Borosilicate glass probes can withstand temperatures up to500C and vitreo
45、us silica probes up to 1000C. Some refractorsof advanced ceramic materials can withstand temperatureshigher than 1000C.6.2.3 Heated Sampling Line Connected to Moisture Re-moval Assembly:6.2.3.1 The sampling line shall be made of stainless steel, orPolytetrafluoroethylene (PTFE).6.2.3.2 The tube diam
46、eter shall be adequate to provide aflow rate that is sufficient to feed the monitors, bearing in mindNOTEKey:1 Lamp 7 Electronic Module2 Transmitter Assembly 8 Data Recorder3 Internal Gas Calibration Cell 9 Stack or Duct4 Receiver Assembly 10 Alignment/Calibration Pipe5 Protective Windows 11 Purge A
47、ir Blower6 Detector 12 Gas Calibration LineFIG. 3 Non-Extractive Path MonitorD5835 95 (2013)4the sampling line length and the pressure characteristics of thesampling pump (6.2.5) used.6.2.3.3 Maintain the sampling line at a temperature of atleast 15C above the water and acid dew-point temperature of
48、the sampled gas. Monitor the temperature.6.2.3.4 In order to reduce the residence time in the samplingline and the risk of physico-chemical transformation of thesample, the gas flow can be greater than that required for theanalytical units; only part of the sample is then analyzed andthe excess flow
49、 discarded through a bypass valve (see Fig. 1).It may be necessary to heat the transport line to avoidcondensation.6.2.4 Secondary Filter:6.2.4.1 A secondary filter may be needed to remove theremaining particulate material, in order to protect the pump(6.2.5) and analyzer. It shall follow the sampling line (6.2.3)immediately downstream of the probe. A filter that retainsparticles greater than 1 m is recommended. Acceptablematerials are PTFE or quartz borosilicate. The size of the filtershall be determined from the required sample flow and themanufacturer
