ASTM D6331-16

Standard Test Method for Determination of Mass Concentration of Particulate Matter from Stationary Sources at Low Concentrations (Manual Gravimetric Method)

SIGNIFICANCE AND USE
5.1 The measurement of particulate matter and collected residue emission rates is an important test method widely used in the practice of air pollution control. Particulate matter measurements after control devices are necessary to determine total emission rates into the atmosphere.  
5.1.1 These measurements, when approved by national, state, provincial, or other regional agencies, are often required for the purpose of determining compliance with regulations and statutes.  
5.1.2 The measurements made before and after control devices are often necessary to demonstrate conformance with regulatory or contractual performance specifications.  
5.2 The collected residue obtained with this test method is also important in characterizing stack emissions. However, the utility of these data is limited unless a chemical analysis of the collected residue is performed.  
5.3 These measurements also can be used to calibrate continuous particulate emission monitoring systems by correlating the output of the monitoring instruments with the data obtained by using this test method.
SCOPE
1.1 This test method2 covers a method for the measurement of particulate matter (dust) concentration in emission gases in the concentrations below 20 mg/m3 standard conditions, with special emphasis around 5 mg/m3.  
1.2 To meet the requirements of this test method, the particulate sample is weighed to a specified level of accuracy. At low dust concentrations, this is achieved by:  
1.2.1 Precise and repeatable weighing procedures,  
1.2.2 Using low tare weight weighing dishes,  
1.2.3 Extending the sampling time at conventional sampling rates, or  
1.2.4 Sampling at higher rates at conventional sampling times (high-volume sampling).  
1.3 This test method differs from Test Method D3685/D3685M by requiring the mass measurement of filter blanks, specifying weighing procedures, and requiring monitoring of the flue gas flow variability over the testing period. It requires that the particulate matter collected on the sample filter have a mass at least five times a positive mass difference on the filter blank. High volume sampling techniques or an extension of the sampling time may be employed to satisfy this requirement. This test method has tightened requirements on sampling temperature fluctuations and isokinetic sampling deviation. This test method has eliminated the in-stack filtration technique.  
1.4 This test method may be used for calibration of automated monitoring systems (AMS). If the emission gas contains unstable, reactive, or semi-volatile substances, the measurement will depend on the filtration temperature.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Published
• Publication Date: 30-Sep-2016
• ICS: 13.040.99 - Other standards related to air quality
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.03 - Ambient Atmospheres and Source Emissions

Relations

• Replaces: ASTM D6331-14 - Standard Test Method for Determination of Mass Concentration of Particulate Matter from Stationary Sources at Low Concentrations (Manual Gravimetric Method)
• Effective Date: 01-Oct-2016
• Refers: ASTM D1356-20a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Sep-2020
• Refers: ASTM D1356-20 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Mar-2020
• Refers: ASTM D3631-99(2017) - Standard Test Methods for Measuring Surface Atmospheric Pressure
• Effective Date: 01-Mar-2017
• Refers: ASTM D3796-09(2016) - Standard Practice for Calibration of Type S Pitot Tubes
• Effective Date: 01-Sep-2016
• Refers: ASTM D1356-15a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Oct-2015
• Refers: ASTM D1356-15 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Jul-2015
• Refers: ASTM D1356-14b - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Dec-2014
• Refers: ASTM D1356-14a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-May-2014
• Refers: ASTM D1356-14 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Jan-2014
• Refers: ASTM E1-13 - Standard Specification for ASTM Liquid-in-Glass Thermometers
• Effective Date: 01-May-2013
• Refers: ASTM D3631-99(2011) - Standard Test Methods for Measuring Surface Atmospheric Pressure
• Effective Date: 01-Oct-2011
• Refers: ASTM E2251-11 - Standard Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids
• Effective Date: 01-May-2011
• Refers: ASTM E2251-10 - Standard Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids
• Effective Date: 01-Nov-2010
• Refers: ASTM D1356-05(2010) - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Apr-2010

Overview

ASTM D6331-16: Standard Test Method for Determination of Mass Concentration of Particulate Matter from Stationary Sources at Low Concentrations (Manual Gravimetric Method) provides an essential framework for quantifying particulate matter (PM) emissions from stationary sources, particularly at emissions below 20 mg/m³ (typically near 5 mg/m³). Widely recognized in the field of air pollution control, this manual gravimetric test method ensures the accurate determination of particulate concentrations, supporting regulatory compliance and performance verification of emission control technologies.

This standard is developed by ASTM International Committee D22 on Air Quality. It is referenced by regulatory bodies and often serves as a benchmark for demonstrating adherence to environmental statutes and emission permits.

Key Topics

• Manual Gravimetric Measurement: Utilizes precise and repeatable weighing techniques to determine the mass of particulate matter collected on a filter during sampling. Special care is given to control accuracy, especially when working with low mass concentrations.
• Sampling Techniques: Focuses on extending sampling periods or increasing flow rates to ensure sufficient sample mass, and includes the use of low tare weight weighing dishes for improved sensitivity.
• Quality Assurance: Specifies the need for measurement of filter blanks, tight control of sampling temperature, and continuous monitoring for isokinetic sampling and flue gas variability to minimize measurement uncertainty.
• Regulatory Compliance: The method supports the demonstration of compliance with national, state, or local air quality regulations. Measurements are essential before and after emission control devices to assess their effectiveness and compliance with environmental performance specifications.
• Calibration of Monitoring Systems: Results from this manual test can be used to calibrate and validate automated particulate emission monitoring systems, ensuring ongoing accuracy of continuous emissions measurement.

Applications

ASTM D6331-16 is broadly applied in environmental monitoring and industrial emission testing, with practical applications including:

• Regulatory Reporting: Provides emission data required by authorities for permitting and environmental compliance.
• Performance Testing: Assesses the efficiency of particulate matter removal devices like baghouses, electrostatic precipitators, and wet scrubbers by comparing emissions before and after treatment.
• Stack Emission Characterization: Collects particulate samples for further chemical analysis, aiding in the source identification and environmental impact assessment.
• Calibration of Automated Systems: Forms a basis for calibration and correlation of continuous emissions monitoring systems (CEMS) at low PM concentrations.

By ensuring a robust, manual measurement for low-concentration PM, ASTM D6331-16 supports accurate emission inventories and reliable operation of air quality monitoring programs in industries such as power generation, cement manufacturing, waste incineration, and metals processing.

Related Standards

For best practices and compliance, the following related standards and methods are often referenced alongside ASTM D6331-16:

• ASTM D3685/D3685M: Test Methods for Sampling and Determination of Particulate Matter in Stack Gases (higher concentrations, differing methodology)
• ASTM D3154: Average Velocity in a Duct (Pitot Tube Method) - essential for flow measurement in emission sampling.
• ASTM D1193: Specification for Reagent Water - for sample preparation and analysis.
• ISO 9096: International equivalent for manual gravimetric sampling of PM from stationary sources.
• ISO 10780: Measurement of velocity and volume flow rate in stack sampling.
• US EPA Reference Methods: Such as Method 5 and Method 17 for PM sampling, and 40 CFR 60, Appendix A criteria for sampling ports and procedures.

Keywords: ASTM D6331-16, particulate matter, stationary source emissions, gravimetric method, low concentration PM, emission measurement, stack sampling, air pollution control, regulatory compliance, manual sampling, emission monitoring, calibration.

By following ASTM D6331-16, organizations can ensure that stack emission measurements are performed to the highest standards, enabling confidence in results and supporting environmental stewardship.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6331 − 16
Standard Test Method for
Determination of Mass Concentration of Particulate Matter
from Stationary Sources at Low Concentrations (Manual
Gravimetric Method)
This standard is issued under the fixed designation D6331; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5 The values stated in SI units are to be regarded as
2 standard. No other units of measurement are included in this
1.1 This test method covers a method for the measurement
standard.
of particulate matter (dust) concentration in emission gases in
1.6 This standard does not purport to address all of the
the concentrations below 20 mg/m standard conditions, with
safety concerns, if any, associated with its use. It is the
special emphasis around 5 mg/m .
responsibility of the user of this standard to establish appro-
1.2 To meet the requirements of this test method, the
priate safety, health, and environmental practices and deter-
particulate sample is weighed to a specified level of accuracy.
mine the applicability of regulatory limitations prior to use.
At low dust concentrations, this is achieved by:
1.7 This international standard was developed in accor-
1.2.1 Precise and repeatable weighing procedures,
dance with internationally recognized principles on standard-
1.2.2 Using low tare weight weighing dishes,
ization established in the Decision on Principles for the
1.2.3 Extendingthesamplingtimeatconventionalsampling
Development of International Standards, Guides and Recom-
rates, or
mendations issued by the World Trade Organization Technical
1.2.4 Sampling at higher rates at conventional sampling
Barriers to Trade (TBT) Committee.
times (high-volume sampling).
2. Referenced Documents
1.3 This test method differs from Test Method D3685/
D3685M by requiring the mass measurement of filter blanks,
2.1 ASTM Standards:
specifying weighing procedures, and requiring monitoring of
D1193Specification for Reagent Water
the flue gas flow variability over the testing period. It requires
D1356Terminology Relating to Sampling and Analysis of
that the particulate matter collected on the sample filter have a
Atmospheres
mass at least five times a positive mass difference on the filter
D2986Practice for Evaluation of Air Assay Media by the
blank.Highvolumesamplingtechniquesoranextensionofthe
Monodisperse DOP (Dioctyl Phthalate) Smoke Test
sampling time may be employed to satisfy this requirement.
(Withdrawn 2004)
This test method has tightened requirements on sampling
D3154Test Method for Average Velocity in a Duct (Pitot
temperature fluctuations and isokinetic sampling deviation.
Tube Method)
This test method has eliminated the in-stack filtration tech-
D3631Test Methods for Measuring Surface Atmospheric
nique.
Pressure
D3670Guide for Determination of Precision and Bias of
1.4 This test method may be used for calibration of auto-
Methods of Committee D22
matedmonitoringsystems(AMS).Iftheemissiongascontains
D3685/D3685MTestMethodsforSamplingandDetermina-
unstable, reactive, or semi-volatile substances, the measure-
tion of Particulate Matter in Stack Gases
ment will depend on the filtration temperature.
D3796Practice for Calibration of Type S Pitot Tubes
E1Specification for ASTM Liquid-in-Glass Thermometers
1 E2251Specification for Liquid-in-Glass ASTM Thermom-
This test method is under the jurisdiction of ASTM Committee D22 on Air
Quality and is the direct responsibility of Subcommittee D22.03 on Ambient
eters with Low-Hazard Precision Liquids
Atmospheres and Source Emissions.
Current edition approved Oct. 1, 2016. Published October 2016. Originally
approved in 1998. Last previous edition approved in 2014 as D6331–14. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D6331-16. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
This test method was originally based on ISO/CD 12141.3, “Stationary Source Standards volume information, refer to the standard’s Document Summary page on
Emissions—Determination of Mass Concentration of Particulate Matter (Dust) at the ASTM website.
Low Concentrations—Manual Gravimetric Method”, available from International The last approved version of this historical standard is referenced on
Organization for Standardization, Casa Postale 56, CH-1211, Geneva Switzerland. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6331 − 16
2.2 ISO Standards: specifiedconditionsandthatremainsupstreamofthefilterand
ISO5725Precision of test methods—Determination of re- on the filter after drying under specified conditions are consid-
peatability and reproducibility by inter-laboratory tests ered to be particulate matter. However, for the purposes of
ISO9096Stationary source emissions—Determination of some regulatory standards, the definition of particulate matter
concentrationandmassflowrateofparticulatematerialin may extend to condensibles or reacted materials collected
gas-carrying ducts. Manual gravimetric method under specified conditions (for example, specified temperature
ISO10780Stationary source emissions—Measurement of lower than the flue gas temperature).
velocity and volume flow rate of gas stream in ducts
3.2.8 sampling line—the line in the sampling plane along
2.3 U.S. EPA Documents:
which the sampling points are located bounded by the inner
Reference Method 1, 40 CFR 60, Appendix ASample and
duct wall.
velocity traverses for stationary sources
3.2.9 sampling plane—the plane normal to the centerline of
Reference Method 3A, 40 CFR 60,AppendixADetermina-
the duct at the sampling position.
tion of oxygen and carbon dioxide concentrations in
3.2.10 sampling point—the specific position on a sampling
emissions from stationary sources (instrumental analyzer
line at which a sample is extracted.
procedure)
3.2.11 weighing control procedures—quality control proce-
3. Terminology
duresutilizedfordetecting/correctingapparentmassvariations
due to climatic or environmental changes between pre- and
3.1 Fordefinitionsoftermsusedinthistestmethod,referto
post-sampling weighing series.
Terminology D1356.
3.2.11.1 Discussion—Inthisprocedure,controlparts,which
3.2 Definitions of Terms Specific to This Standard:
are identical to those to be weighed for dust measurement and
3.2.1 filtrationtemperature—thetemperatureofthesampled
arepretreatedunderthesameconditions,areused.Thecontrol
gas immediately downstream of the filter.
parts are kept free from dust contamination.
3.2.2 high volume sampling—sampling at higher rates than
typical in Test Methods D3685/D3685M by using larger
4. Summary of Test Method
diameter nozzles and higher flow rates to maintain isokinetic
4.1 A sample stream of the gas is extracted for a measured
sampling conditions.
period of time at a controlled flow rate, and the volume of gas
3.2.2.1 Discussion—Nozzlesizesaretypically20to50mm,
3 collected is subsequently measured. The particulate matter
with corresponding flow rates from 5 to 50 m /s.
(dust) entrained in the gas sample is separated by a pre-
3.2.3 hydraulic diameter, d
h
weighed filter, which is then dried and reweighed. Deposits
4 3area of sampling plane
upstream of the filter in the sampling equipment are also
d 5 (1)
h
perimeter of sampling plane
recovered and weighed. The increase of mass of the filter and
the deposited mass collected upstream of the filter are attrib-
3.2.4 measurement series—successive measurements car-
uted to particulate matter collected from the sampled gas. The
ried out at the same sampling plane and at the same process
ratio of the mass of the particulate matter collected to the
conditions.
volume of gas collected allows for the calculation of the flue
3.2.5 out-of-stack filtration—a sampling technique where
gas particulate concentration.
the filter, in its filter housing, collects particulate matter under
4.2 Valid measurements can be achieved only when:
controlled temperature conditions outside of the stack or duct.
4.2.1 The gas stream in the duct at the sampling plane has a
3.2.6 overall blank—the sample taken in a manner identical
sufficiently steady and measurable velocity, a sufficient tem-
to the flue gas test samples, except that the sampling duration
perature and pressure, and a sufficiently homogeneous compo-
is shortened to less than 1 min.
sition;
3.2.6.1 Discussion—The overall blank value is expressed in
3 4.2.2 The flow of the gas is parallel to the centerline of the
thesameunitsasthemeasurementresult(forexample,mg/m )
duct across the whole sampling plane;
using the average sampling volume of the measurement series.
4.2.3 Sampling is carried out without disturbance of the gas
The overall blank includes possible deposits on the filter and
stream, using a sharp edged nozzle facing into the stream;
surfaces upstream of the filter in contact with the sample gas.
4.2.4 Isokinetic sampling conditions are maintained
3.2.7 particulatematter(dust)—solidparticlesofanyshape,
throughout the test;
structure, or density dispersed in the gas phase at flue gas
4.2.5 Samples are taken at a preselected number of stated
temperature and pressure conditions.
positions in the sampling plane to obtain a representative
3.2.7.1 Discussion—In accordance with the described test
sample for a non-uniform distribution of particulate matter in
method, all material that may be collected by filtration under
the duct or stack.
4.2.6 The sampling train is designed and operated to avoid
condensation and to be leak free;
Available from International Organization for Standardization (ISO), ISO
Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
4.2.7 Dust deposits upstream of the filter are recovered or
Geneva, Switzerland, http://www.iso.org.
taken into account, or both; and
AvailablefromUnitedStatesEnvironmentalProtectionAgency(EPA),William
4.2.8 The sampling and weighing procedures are adapted to
Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460,
http://www.epa.gov. the expected dust quantities.
D6331 − 16
5. Significance and Use Convenient access ports and a working platform are required
for the testing. See U.S. EPAReference Method 1, 40 CFR 60,
5.1 The measurement of particulate matter and collected
Appendix A, or ASTM Test Method D3685/D3685M for
residue emission rates is an important test method widely used
additional criteria.
in the practice of air pollution control. Particulate matter
measurements after control devices are necessary to determine 7.2 Sampling Plane:
total emission rates into the atmosphere. 7.2.1 The sampling plane shall be situated in a length of
5.1.1 These measurements, when approved by national, straight duct (preferably vertical) with a constant shape and
state, provincial, or other regional agencies, are often required constant cross-sectional area.The sampling shall be conducted
for the purpose of determining compliance with regulations asfardownstreamandupstreamfromanyobstructionthatmay
and statutes. cause a disturbance and produce a change in the direction of
5.1.2 The measurements made before and after control flow (disturbances can be caused by bends, fans, or control
devices are often necessary to demonstrate conformance with equipment). The sampling plane location shall maximize the
regulatory or contractual performance specifications. distance downstream from a flow disturbance.
7.2.2 Measurementsatallthesamplingpointsdefinedin7.3
5.2 The collected residue obtained with this test method is
shall prove that the gas stream at the sampling plane meets the
also important in characterizing stack emissions. However, the
following requirements:
utility of these data is limited unless a chemical analysis of the
7.2.2.1 The angle of gas flow is less than 15° with regard to
collected residue is performed.
theductaxis(methodforestimationisindicatedinAnnexCof
5.3 These measurements also can be used to calibrate
ISO10780);
continuous particulate emission monitoring systems by corre-
7.2.2.2 No local negative flow is present;
lating the output of the monitoring instruments with the data
7.2.2.3 The minimum velocity is measurable by the test
obtained by using this test method.
method used (for example, using Test Method D3154,a
differential pressure larger than 5 Pa (0.02 in. H O)); and
6. Interferences
7.2.2.4 Theratioofthehighesttolowestlocalgasvelocities
6.1 Gaseous species present in stack gases that are capable
is less than 3:1.
of reacting to form particulate matter within the sample train
7.2.3 Iftheaboverequirementscannotbemet,thesampling
can result in positive interference.
location will not be in compliance with this test method.
6.1.1 Examples include the potential reaction of sulfur
7.3 Minimum Number and Location of Sampling Points:
dioxide(SO )toaninsolublesulfatecompoundinthemoisture
7.3.1 SeeTest Method D3154, Section 8, Figs. 7 and 8, and
portion of the system (such as with limestone in flue gas
Tables 1 and 2.
following a wet flue gas desulfurization system (FGDS) to
7.4 Access Ports:
form calcium sulfate (CaSO ) or the reaction with ammonia
7.4.1 Provide sampling ports for access to the sampling
gas (NH ) to form ammonium sulfate (NH ) SO and the
3 4 2 4
points selected, in accordance with 7.3 and Test Method
potential reaction of hydrogen fluoride (HF) with glass com-
D3154.
ponents in the sample train with resultant collection of silicon
7.4.2 Ensure that the port dimensions offer ample space for
tetrafluoride (SiF ) in the impingers.
the insertion and removal of the sampling equipment and
6.1.2 Corrosion residue in rinse of metallic nozzle and
associated devices.
metallic probe liner when used in supersaturated, acidic flue
7.4.3 Sample ports must be clean and free of debris, and
gas streams.
allow for clean access/egress of the sample nozzle and probe.
6.2 Volatile matter existing in solid or liquid form in the
stack gas may vaporize after collection on the sample train 8. Velocity and Gas Composition Measurement
filtration material due to continued exposure to the hot sample Apparatus
stream during the sampling period. Such an occurrence would
8.1 See Section 6, Test Method D3154.
result in a negative interference. See also Appendix X1.
9. Sampling Apparatus and Equipment
6.3 Residualmaterialexistinginsamplenozzle,probe,filter
9.1 Sampling Train—For schematic drawings of the major
housing, or glassware prior to testing.
sampling train components refer to Fig. 1 for the out-of-stack
6.4 Residue present in solvent and water reagent(s).
method.
6.5 Transient dust and material present at sampling location
9.1.1 The materials of construction of components (such as
(platform and port) and cleanup area.
thenozzle,probe,unions,filterholder,gaskets,andotherseals)
shall be materials that will withstand corrosive or otherwise
7. Requirements for Sampling Plane and Sampling
reactivecomponentsorpropertiesofthestackorgasstream,or
Points
both. Recommended materials for a normal range of stack and
7.1 Representative sampling is possible when a suitable sample conditions include PTFE fluoroplastic (up to 175°C),
location that has sufficiently homogeneous gas velocity at the 316 stainless steel (up to 800°C), and some resistant silicone
sampling plane is available. materials (up to 150°C). Extreme temperature conditions may
7.1.1 Perform sampling at a sufficient number of sampling require the use of materials such as quartz or a nickel-
points, which are usually located on several sampling lines. chromium alloy, or a water-cooled probe may be used.
D6331 − 16
FIG. 1 Out-of-Stack Sampling Train—Example of a Dry Basis Measurement System
9.2 Elements of the Sampling Train—Thesamplingtrainfor Perform the leak check with the filter holder in the oven. The
collecting particulate matter and collected residue from a gas filter holder shall again remain leak-less.
stream flowing through a stack consists of the following (4)Remove the filter holder from the oven and cool for 30
interconnected elements: min. Again run the leak check.
(5)Elevate the temperature of the oven to the maximum
9.3 Nozzles—The first part of the sampling equipment to
temperature expected during the test. Place the filter holder in
encounterthedustormoisture-ladengasstream,orboth,isthe
the oven, and heat it for 30 min. Repeat the leak test.
nozzle. To extract a representative sample of gas and particu-
(6)Removethefilterholderandallowittocoolfor30min.
late matter, the nozzle used for sampling shall be within a
Run the final leak check. If the filter holder passes these leak
narrow range of inside diameters.
check procedures, then it is properly designed to remain leak
9.3.1 The probe nozzle is provided with a sharp, tapered
free when properly maintained.
leading edge and is constructed of either glass, virgin seamless
(7)If the filter holder passes the leak checks at the lower
316 stainless steel tubing, or other virgin corrosion-resistant
temperatures, but not the maximum temperature, replace the
metal or material that is appropriate for the temperature of the
filter holder.
gas to be sampled formed in a button-hook or elbow configu-
(8)If the filter holder is unable to pass the leak check
ration. The tapered angle shall be <30° with the taper on the
procedure at 100°C, reject the holder unless sampling is to be
outside to establish a constant inside diameter (ID). The
performed only at ambient temperature.
straight length from the nozzle opening to the first bend of the
9.4.2 Filter Heating System—A heating system capable of
nozzle shall be greater than 30 mm. Glass nozzles should be
maintaining the filter holder at the specified filtration tempera-
used whenever possible and especially in wet, corrosive gas
ture 68°C during sampling.
streams.
9.4.3 Filter Thermometer—Monitoring device for measur-
9.3.2 ArangeofnozzleIDs,forexample,3to15mm(0.125
ing temperature inside the filter holder to within 1°C during
to 0.5 in.), in increments of 1.5 mm are required for isokinetic
sampling.
sampling. Larger nozzle sizes may be required if high volume
9.4.4 Before sampling, check the heating system and the
sampling trains are used or if very low flows are encountered.
temperature monitoring device. It is important that the heating
Inspect the nozzle before use for roundness and for damage to
element be easily replaceable in case of a malfunction during
the tapered edge, such as nicks, dents, and burrs. Do not use a
sampling.
damaged nozzle. Check the diameter with a micrometer or
other acceptable measuring device. A slight variation from
9.5 Probes:
exact sizes should be expected due to machining tolerances.
9.5.1 The sampling probe liner shall be constructed of
Engrave each nozzle with an identification number for inven-
corrosion-resistant, seamless tubing with an outside diameter
tory and calibrating purposes.
(OD)ofabout16mm,usuallyencasedwithinaheatingsystem
9.4 Filter Holders and Heating: within a stainless steel sheath with an OD of 25 mm. A
9.4.1 A filter holder constructed of borosilicate or quartz larger-diameter sheath or over-sheath may be used. Whenever
glass. Use a glass/silicone rubber or TFE-fluorocarbon frit to practical, use borosilicate or quartz glass liners; alternatively,
support the filter inside the filter holder. The holder shall be metalseamlesslinersof316stainlesssteel,anickel-chromium
durable,easytoload,andleakfreeinnormalapplications.Itis alloy, nickel-iron-chromium alloy (UNS N08825), titanium or
recommended to perform the following leak check procedure titaniumalloy(seeDS56I6),orothercorrosionresistantmetal
prior to using a new filter holder assembly to ensure that each or material that is appropriate for the temperature of the stack
filterholderisabletobeassembledinaleak-freemanner.This being sampled may be used. A heating system that will
leak check procedure is not intended to be used for pretest and maintain an exit gas temperature of 120 6 8°C (250 6 15°F)
posttest leak checks of the sampling system. duringsamplingisrequiredexceptwhenthetemperatureofthe
(1)Assemble the filter holder and filter. stack is high enough to maintain such a temperature without a
(2)Perform the standard leak check at 50 kPa vacuum at heating system. Other temperatures may be specified for a
ambienttemperature.Aleakagerateof570mL/minisallowed; particular application, but the heating system must maintain
however, under these laboratory conditions, the entire train 68°C. Use either borosilicate or quartz glass liners for stack
shall be leak-less. temperatures up to about 480°C (900°F), but use quartz glass
(3)Place the filter holder in an oven (a method filter heater liners from 480 to 900°C. Either type of liner may be used at
compartment can be used) at about 100°C for about 30 min. higher temperatures for short time periods. However, do not
D6331 − 16
exceedtheabsoluteupperlimits,thatis,thesofteningtempera- system that cools the gas stream and allows measurement of
tures of 820°C and 1500°C for borosilicate and quartz, the condensed water and the water vapor leaving the
respectively. If metal or other material is used, do not exceed condenser, each to within 1 mL or 1 g, may be used.
the softening or degradation temperature specific to that 9.6.4 TestthestandardGreenburg-Smithimpingerbyfilling
material. Metal probe liners should be heat-treated or baked at
the inner tube with water. If the water does not drain through
350°C or higher before first use to aid in removal of oils used theorificein6to8sorless,replacetheimpingertiporenlarge
in manufacture, as solvent cleaning will not always remove
ittopreventanexcessivepressuredropinthesamplingsystem.
those oils from the inner surface of the metal tubing. It is Check each impinger visually for damage, including breaks,
recommended that metal liners be of virgin material having
cracks, or manufacturing flaws, such as poorly shaped connec-
never been used on any other source emissions test. Metal tions.
probe liners used in wet acidic gas streams have been docu-
9.6.5 Impinger Thermometer—Monitoring device for mea-
mented to have a significant contribution of corrosion byprod-
suring temperature of gas exiting the fourth impinger (see
ucts in the particulate catch sample. When using metal probe
9.6.3) within 61°C of true value in the range from 0 to 25°C.
liners, the source emission tester, source owner, or regulatory
9.7 Gas Temperature Sensor—For measuring gas tempera-
agency should consider conducting a test to prove the metal
ture to within 61°C. Permanently attach the temperature
linermaterialwillnotcontributesignificantlytotheparticulate
sensortoeithertheprobe(see9.5)orthepitottube(see9.9and
sample under the stack gas conditions. Visually check new
Fig. 1).
probes for breaks or cracks and for leaks on a sampling train.
9.8 Vacuum Lines—Locate all components of the sampling
This includes a proper nozzle-to-probe connection. Check the
system as close together as possible, with direct interconnec-
probe heating system prior to conducting a test program as
tion between successive components in the system wherever
follows:
possible. When direct interconnection is not possible, all
9.5.1.1 Electrically connect and turn on the probe heater for
vacuum (gas sampling) lines shall be of smooth-bore, inert
2 or 3 min. The probe should become warm to the touch.
materialcapableofwithstandinginternalandexternaltempera-
9.5.1.2 After the probe temperature reaches equilibrium
turesatthesamplinglocationandofwithstandingavacuumof
recordtheprobetemperature.Rotatetheprobeonequarterturn
65 kPa without collapse or leakage.
inside the sheath and record the probe temperature after one
minute. Rotate the probe one quarter turn two more times
9.9 Pitot Tube—The pitot tube, Type S design, meeting the
inside the sheath recording the probe temperature after one
requirements of Test Method D3154, shall be used.Attach the
minute at each spot. Average the four probe temperature
pitot tube to the probe as shown in Fig. 1. Visually inspect the
readings.Theprobetemperaturereadingstakenateachquarter
pitot tube for both vertical and horizontal tip alignments. If the
turn shall not vary by more than 5°C from the average probe
tubeispurchasedasanintegralpartofaprobeassembly,check
temperature; otherwise, reject or repair the probe heating
thedimensionalclearances.Repairorreturnanypitottubethat
system.
does not meet specifications. Calibrate the Type S tube
9.5.1.3 Connecttheprobewithanozzleattachedtotheinlet
following the procedures given in Practice D3796.
of the vacuum pump (see 9.10.3).
9.10 Metering System—The metering system, consisting of
9.5.1.4 Activate the pump and adjust the needle valve until
two vacuum gages, a vacuum pump, a dry gas meter with 2%
a flow rate of about 20 L/min is achieved.
accuracy at the required sampling rate, thermometers capable
9.5.1.5 Besuretheproberemainswarmtothetouchandthe
of measuring 61°C of true value in the range from 0 to 90°C,
probe heater is capable of maintaining the exit air temperature
pressure gage, check valves, and related equipment, as shown
at a minimum of 120°C. Otherwise, reject or repair the probe.
in Fig. 1. Other metering systems capable of maintaining
9.6 Condenser—Four impingers connected in series and
sampling rates within 5% of isokinetic and of determining
immersed in an ice bath with leak-free ground-glass fittings or
sample volumes to within 2% may be used. Upon receipt or
any similar noncontaminating fittings.
after construction of the equipment, perform both positive and
9.6.1 The first, third, and fourth impingers shall be the negative pressure leak checks before beginning the system
Greenburg-Smithdesignmodifiedbyreplacingtheinsertswith calibration procedure, as described in Test Methods D3685/
a glass tube that has an unconstricted 13-mm ID and that D3685M. Any leakage requires repair or replacement of the
extends to within 13 mm of the flask bottom. If no analysis of malfunctioning item. Components include the following:
the collected residue is to be performed on the impinger catch,
9.10.1 Differential Pressure Gage—Two inclined manom-
use of glass impingers is not required as long as the gas
etersortheequivalent,asspecifiedinTestMethodD3154.One
moisture content is determined by alternate means (see Test
(called the pitot manometer) is utilized to monitor the stack
Method D3154).
velocity pressure, and the other (called the orifice meter) to
9.6.2 ThesecondimpingershallbeaGreenburg-Smithwith
measure the orifice pressure differential. Initially, check the
the standard tip and plate. Modifications (for example, using gages against a gage-oil manometer at a minimum of three
flexible connections between impingers, materials other than points: 5, 125, and 250 Pa. The gages shall read within 5% of
glass, or a flexible vacuum hose to connect the filter holder to the gage-oil monometer at each test point. Repair or reject any
the condenser) may be used. gage that does not meet these requirements
9.6.3 The fourth impinger outlet connection shall allow for 9.10.2 Dry Gas Meter—A volume meter is required for
insertion of a thermometer (see 9.6.5). Alternatively, any measuring the total sample flow for each test.Acalibrated dry
D6331 − 16
gas test meter (2% accuracy at a flow rate of 20 L/min) is the brush for the nozzle may be used. At a minimum use a new
most satisfactory totalizing volume meter available for source probe and nozzle brush for each test program.
test work. Calibrate the meter in the laboratory prior to use 9.17.2 WashBottles,two500-mLwashbottlesforprobeand
with a positive displacement liquid meter, and determine the glassware rinsing. Glass bottles or PTFE squeeze bottles are
correction factor as necessary. required.
9.17.3 Sample Storage Container, 500 or 1000-mL chemi-
9.10.2.1 Dry Gas Meter Thermometer—Two monitoring
cally resistant, borosilicate glass bottles for storage of acetone
devices for measuring temperature to within 1°C in the range
rinses, with leak-proof screw caps with leak-proof, rubber-
from0to90°Cofthegasenteringandexitingfromthedrygas
backedTFE-fluorocarboncapliners.Wide-mouthedbottlesare
meter (see 9.10.2).
easiest to use, but narrow mouth bottles are less prone to
9.10.3 Vacuum Pump—An airtight, leak-free vacuum pump
leakage.Precleanedglassbottlesarerecommended.Inspectthe
with coarse and fine flow controls capable of maintaining a
cap seals and the bottle cap seating surfaces for chips, cuts,
flow rate of 20 L/min for a pump inlet vacuum of 50 kPa is
cracks, and manufacturing deformities that would permit
used to draw the gas sample.
leakage.
9.10.4 Vacuum Gauge, for measuring pressure at the
9.17.4 Petri Dishes, glass, polyethylene, styrene, or similar
vacuum pump inlet, capable of measuring 63 kPa over the
material petri dishes for storage and for transportation of the
range from 0 to 101 kPa. Check it against a mercury U-tube
filter and collected sample.
manometer upon receipt, and yearly thereafter.
9.17.5 Graduated Cylinder, Triple Beam Balance, or Elec-
9.11 Nomograph, to determine the isokinetic sampling. Its
tronic Scale, a graduated cylinder, a triple beam balance, or
function may be applied with a hand-held programmable
electronic scale to measure the water condensed in the im-
calculator or laptop computer.
pingers during sampling. The graduated cylinder may be used
to measure water initially placed in the first and second
9.12 Thermometers—Temperature measuring devices such
impingers. In either case, the required accuracy is 1 mLor 1 g;
asRTDs,thermistors,andorganicliquid-in-glassthermometers
therefore, use a cylinder with subdivisions of ≤2 mL. Use a
meetingtherequirementsofspecificapplicationsmaybeused.
triple beam balance capable of weighing to the nearest 1.0 g.
ASTM thermometers, S59C and S63C as identified in Speci-
9.17.6 Plastic Storage Containers, several airtight plastic
ficationE2251,maybesubstitutedforthermomenters59Cand
containers for storage of silica gel.
63C directly. In addition, precision digital thermometers based
9.17.7 Funnel and Rubber Policeman—Afunnelandrubber
on resistance temperature detectors (RTDs), thermistors, or
policeman to transfer the used silica gel from the impinger to
thermocouples, or organic liquid-in-glass thermometers with
astoragecontainerunlesssilicagelisweighedinthefieldafter
equivalent or better accuracy and precision in the appropriate
the test.
temperature range may be used. See Test Methods D3685/
9.17.8 Desiccator, used to dry filters before weighing. Use
D3685M for calibration procedures.
anhydrous CaSO (see 10.5) as the desiccant.
9.13 Barometer—An aneroid, or other barometer capable of
9.17.9 Laboratory Drying Oven, capable of heating filters
measuring atmospheric pressure to within 6300 Pa shall be
and rinse solution containers to 102°C.
used. Calibrate the barometer against a mercury-in-glass ba-
9.18 Analytical Equipment:
rometer or the equivalent, as described inTest Method D3631.
9.18.1 Weighing Dishes, polyethylene petri dish or other
9.13.1 Alternatively, the absolute barometric pressure may
low tare weight container to facilitate filter weighing. Use a
beobtainedfromanearbyweatherservicestationandadjusted
250-mL PTFE beaker insert or equivalent low tare weight
for elevation difference between the station and the sampling
weighing dish for evaporation of the acetone/water rinse.
point. Either subtract 10 Pa/m from the station value for an
9.18.2 Balance, analytical grade, capable of weighing the
elevation increase or add the same for an elevation decrease.
filter and the sample beaker to within 60.1 mg.
Replace the barometer if it cannot be adjusted to agree within
300 Pa of the reference barometric pressure.
10. Reagents and Materials
9.14 Wet Test Meter, with a capacity of 3.5 m /h or 30 Lfor
10.1 Purity of Reagents—Reagent grade chemicals shall be
each revolution with an accuracy of 61.0%, to calibrate the
usedinalltests.Allreagentsshallconformtothespecifications
dry test meter.
of the committee on Analytical Reagents of the American
Chemical Society.
9.15 Orsat Gas Analyzer or equivalent instrumental analy-
sis of O and CO , stack gas analyzer, as described in Test
2 2 10.2 Purity of Water—Unless otherwise specified, water
MethodD3154orU.S.EPAReferenceMethod3A,40CFR60,
shall be Type III reagent water conforming to Specification
Appendix A.
D1193.
9.16 U-Tube Manometer, a water manometer or pressure
sensor capable of measuring gas pressure to within 0.33 kPa.
Reagent Chemicals, American Chemical Society Specifications, American
9.17 Sample Recovery Apparatus: Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory
9.17.1 Probe Liner and Nozzle Brushes, nylon bristle brush
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
withastainlesssteelwirehandleorPTFE/nylontubehandleas
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
long as the probe, and a separate smaller and very flexible MD.
D6331 − 16
10.3 Determine reagent blanks on the acetone and reagent DL * 100 ⁄3
~ !
water.
At a particulate concentration of 5 mg/scm and sampling at
10.4 Acetone—Reagent ACS grade acetone with ≤0.001%
1.0 standard cubic foot per minute (0.028 standard cubic
residueinglassbottles.Acetonesuppliedinmetalcontainersis
metres per minute), the sampling time needs to be approxi-
unacceptable due to the prevalently high residue levels. Reject
mately 36 minutes.
the acetone if blank residue mass (see 10.3) is >0.001% of the
11.2 Taking into account the objective of the measurements
total acetone mass.
and the flue gas characteristics:
10.5 Calcium Sulfate, Anhydrous—CaSO , indicating type,
11.2.1 Choose a relevant temperature for conditioning and
for use in desiccator.
drying the filter before and after sampling (see 14.2); and
11.2.1.1 Set the out-of-stack filter temperature as specified
10.6 Crushed Ice.
by the regulatory agency or as determined for technical
10.7 Silica Gel—SiO , indicating-type, 6 to 16-mesh, for
reasons.
use in the fourth impinger in the condenser. Dry at 175°C for
11.2.2 Takeanoverallblanksampleaftereachmeasurement
at least 2 h prior to use.
series and at least after each day of sampling if the measure-
10.8 Gloves, insulated, heat-resistant.
ment series covers multiple days following the sampling
procedure described in 12.3, either without starting the suction
10.9 Filter Material:
device or for a sample duration less than one minute. This
10.9.1 Useglassfiberfilterswithoutorganicbinders.Quartz
blanksampleleadstoanestimationofthedispersionofresults
glass fiber filter are recommended for use in most applications
related to the whole procedure as carried out by the operators
(especially in gas streams with SO or other acid gases).
for a near zero dust concentration, due to contamination of
However other filter materials (for example, PTFE,
filters and of rinsing solutions during handling on-site,
polycarbonate,ceramic,orcellulose)maybeusedprovidedthe
transport, storage, handling in the laboratory, and weighing
stack tester or source owner can demonstrate the filter material
procedures, and so forth. The overall blank can also evaluate
will not bias the results due to chemical reaction between the
the effectiveness of the rinse procedures.
filter material and the effluent gas matrix. The filters shall
exhibit at least 99.95% collection efficiency of a 0.3-mm
11.3 Weighing Procedures:
dioctyl phthalate smoke particle, in accordance with Practice 11.3.1 The parts to be weighed are the filter and the rinse
D2986. The manufacturer’s quality control test data are suffi-
solution container.
cient for validation of efficiency. Check the filters for 11.3.2 Pre- and post-treat all the filters and rinse solution
irregularities, flaws, or pinholes by holding them up against a
containers in accordance with 11.4 and 11.6 following the
light source. procedures detailed in 11.5.
11.4 Pre-Sampling Treatment of Weighed Parts:
11. Weighing and Pre-Sampling Procedure
11.4.1 Heateachfilter(see10.9.1)onanumberedcontainer
11.1 General Aspects—Before carrying out any
and rinse solution container (see 9.18.1) in a laboratory drying
measurements, discuss the purpose of the sampling and the
oven(see9.17.9)for2hoursatthetemperatureofthesampling
sampling procedures with the plant personnel concerned. The
(see 11.2). After removal from the oven, cool to room
nature of the plant process, for example, steady state or cyclic,
temperature in a desiccator (see 9.17.8). After cooling, weigh
can affect the sampling program. If the process can be
each filter and rinse solution container to the nearest 0.1 mg,
performed in a steady state, it is important that this state is
and record the data. Return the filter and rinse solution
maintained during sampling
containertothedesiccator.Afteratleast6hoursofdesiccation,
weigh each filter and rinse solution container to the nearest 0.1
NOTE 1—There may be regulatory requirements for the state of plant
operationsandyoumaywishtoconsultwithregulatorypersonnelaswell. mg, and record the data. When two consecutive weights have
a difference of no more than 0.3 mg, a constant weight is
11.1.1 Agree upon, with the plant management, the dates,
achieved. Average the two weights and report the average as
startingtimes,durationofsurvey,andsamplingperiodsaswell
the pre-sampling weight. If the consecutive weights have a
as plant operating conditions during these periods.
difference of more than 0.3 mg, continue to weigh the part at
11.1.2 Make preliminary calculations on the basis of the
no less than 6 hours of desiccation time between weightings
expected dust loading to determine the appropriate nozzle size
until two consecutive weights have a difference of no more
or sampling conditions, or both. Also determine whether the
than 0.3 mg. Transport weighed filters in petri dishes (see
chosen nozzle size and sampling time will result in sufficient
9.17.4) to the holders.
particulate matter collected to meet weighing requirements.
Longer sampling times or sampling with the use of a larger 11.5 Weighing:
nozzleandhighersampleflowratesmaybenecessarytoobtain 11.5.1 Weigh the filter and rinse solution container on a
the sample filter mass sufficiently greater than the blank filter suitable balance (see 9.18.2) to at least 0.1 mg.
mass. 11.5.2 Since the sample mass is determined by calculating
11.1.3 Discussion—To obtain results with 10 percent uncer- the difference between data often obtained at one or two week
tainty at 0.99 confidence and a reported lab detection limit
(DL) of 0.15 mg, one needs to collect 5.0 mg in the sampling
FilterableParticulateMatterStackTestMethods:PerformanceCharacteristics
system: and Potential Improvements, EPRI, PaloAlto, CA: 2013, Report No. 3002000975.
D6331 − 16
intervals, special care is required to avoid weighing errors boiling and reduce the pressure to 40 kPa (absolute).
related to balance drift, to insufficient temperature equilibrium Periodically, increase the temperature as well as the pressure.
of parts to be weighed, and to climatic changes (see examples For the last period, maintain them at 140°C or lower tempera-
in Appendix X2). Therefore, before performing any weighing, ture to avoid boiling and 20 kPa (absolute).
validate the weighing procedure.
11.7.3.3 Alternatively, evaporation can be performed by
11.5.3 Before each weighing series:
placing the rinse solution container on a hot plate inside a
11.5.3.1 Calibrate the balance against standard weights;
laboratory hood for ventilation of the vapors and setting the
11.5.3.2 Perform additional checks by weighing control
temperature of the hot plate such that the rinse solution does
parts that are identical to the others and pretreated in the same
not boil.
conditions, but kept free from contamination, and;
11.7.4 After the evaporation, place the rinse solution con-
11.5.3.3 Record the climatic conditions in the room.
tainers in the drying oven for 2 hours at the same temperature
11.5.4 Give attention also to weighing artifacts related to:
chosen for the post sampling treatment of the filters (see 11.4
11.5.4.1 Electrostatic charges, which may have to be dis-
– 11.6). Transfer the rinse solution containers to the desiccator
charged or neutralized; insert an antistatic device inside the
for cooling to room temperature.After cooling weigh the rinse
balance enclosure; recommend blowing off outside of PTFE
solution containers, including the deposits, to the nearest 0.1
beakerinsertwhilemovingitfromthedesiccatortothebalance
mg,andrecordthedata.Returntherinsesolutioncontainersto
to eliminate static attraction of dust onto the beaker.
the desiccator for at least 6 hours of desiccation. After
11.5.4.2 Hygroscopic characteristics of the filter material or
desiccation, weigh each rinse solution container to the nearest
dusts, or both, which may lead to an increase of mass; insert a
0.1 mg, and record the data. When two consecutive weights
dryrite material (calcium sulfate, anhydrous (CaSO )) inside
4 have a difference of no more than 0.3 mg, a constant weight is
the balance enclosure; and
achieved. Average the two weights and report the average as
11.5.4.3 Small differences in temperature between the part
the post-sampling weight. If the consecutive weights have a
to be weighed and the environment may disturb the balance;
difference of more than 0.3 mg, continue to weigh the rinse
equilibrate the temperature of the part being weighed to the
solution container at no less than 6 hours of desiccation time
balance room temperature.
between weightings until two consecutive weights have a
difference of no more than 0.3 mg.
11.6 Post-Sampling Treatment of Filters:
11.7.5 Obtain at least one blank value for each solvent,
11.6.1 Dry filters in a drying oven for at least 2 hours at the
using the same approximately volume as used in the rinsing.
temperature of the sampling (see 11.2 for specific cases).
11.6.2 After drying, cool the filters to room temperature in
12. Sampling
a desiccator as described in 11.4.
11.6.3 Aftercooling,weigheachfiltertothenearest0.1mg,
12.1 Preparation:
and record the data. Return the filter to the desiccator for at
12.1.1 Clean (brushed and rinsed), calibrate, and check all
least6hoursofdesiccation.Afterdesiccation,weigheachfilter
the equipment before moving it to the test site. Exercise care
to the nearest 0.1 mg, and record the data. When two
not to reuse any part of a sampling train that has previously
consecutive weights have a difference of no more than 0.3 mg,
been used for high dust concentration sampling without dis-
a constant weight is achieved. Average the two weights and
mantling and thorough cleaning.
reporttheaverageasthepost-samplingweight.Iftheconsecu-
12.1.2 Dependingonthemeasurementprogram,preparethe
tiveweightshaveadifferenceofmorethan0.3mg,continueto
filter and associated parts to be weighed for each sample run.
weigh the filter at no less than 6 hours of desiccation time
This includes parts for the overall blank tests and additional
between weightings until two consecutive weights have a
parts to accommodate process and equipment malfunctions.
difference of no more than 0.3 mg.
12.1.3 Perform the weighing procedures in accordance with
11.7 Post-Sampling Treatment of the Rinsing Solutions:
11.3.
11.7.1 Take all the rinsing solutions (water and acetone)
12.1.4 Protect all the weighed parts, including the suction
fromallpartsupstreamofthefilter,asdescribedin12.4,tothe
tube and the other parts or equipment that will come into
laboratoryforfurthertreatment.Exercisecarethatnocontami-
contact with the sample (and will be rinsed later) from
nation occurs.
contamination during transportation and storage.
11.7.2 Transfer the solutions quantitatively to the dried and
12.2 Pre-Sampling Measurements:
pre-weighed rinse solution containers (see 11.4). Do not boil
the solvent mixtures during the evaporation process in 11.7.3. 12.2.1 Depending on the dimensions of the duct, which are
tobeverifiedusingameasuringrod,surveyor’stransit,orother
Use smaller vessels as the volume of the solution is reduced
through the evapor
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6331 − 14 D6331 − 16
Standard Test Method for
Determination of Mass Concentration of Particulate Matter
from Stationary Sources at Low Concentrations (Manual
Gravimetric Method)
This standard is issued under the fixed designation D6331; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers a method for the measurement of particulate matter (dust) concentration in emission gases in the
3 3
concentrations below 20 mg/m standard conditions, with special emphasis around 5 mg/m .
1.2 To meet the requirements of this test method, the particulate sample is weighed to a specified level of accuracy. At low dust
concentrations, this is achieved by:
1.2.1 Exercising extreme care in weighing,Precise and repeatable weighing procedures,
1.2.2 Using low tare weight weighing dishes,
1.2.3 Extending the sampling time at conventional sampling rates, or
1.2.4 Sampling at higher rates at conventional sampling times (high-volume sampling).
1.3 This test method differs from Test Method D3685/D3685M by requiring the mass measurement of filter blanks, specifying
weighing procedures, and requiring monitoring of the flue gas flow variability over the testing period. It requires that the particulate
matter collected on the sample filter have a mass at least five times a positive mass difference on the filter blank. High volume
sampling techniques or an extension of the sampling time may be employed to satisfy this requirement. This test method has
tightened requirements on sampling temperature fluctuations and isokinetic sampling deviation. This test method has eliminated
the in-stack filtration technique.
1.4 This test method may be used for calibration of automated monitoring systems (AMS). If the emission gas contains unstable,
reactive, or semi-volatile substances, the measurement will depend on the filtration temperature, and in-stack methods may be more
applicable than out-stack methods for the calibration of automated monitoring systems.temperature.
1.5 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D1193 Specification for Reagent Water
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
D2986 Practice for Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test (Withdrawn
2004)
D3154 Test Method for Average Velocity in a Duct (Pitot Tube Method)
This test method is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheres
and Source Emissions.
Current edition approved June 1, 2014Oct. 1, 2016. Published July 2014October 2016. Originally approved in 1998. Last previous edition approved in 20132014 as
D6331 – 13.D6331 – 14. DOI: 10.1520/D6331-14.10.1520/D6331-16.
This test method is based on ISO/CD 12141.3, “Stationary Source Emissions—Determination of Mass Concentration of Particulate Matter (Dust) at Low
Concentrations—Manual Gravimetric Method”, available from International Organization for Standardization, Casa Postale 56, CH-1211, Geneva Switzerland.This test
method was originally based on ISO/CD 12141.3, “Stationary Source Emissions—Determination of Mass Concentration of Particulate Matter (Dust) at Low
Concentrations—Manual Gravimetric Method”, available from International Organization for Standardization, Casa Postale 56, CH-1211, Geneva Switzerland.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6331 − 16
D3631 Test Methods for Measuring Surface Atmospheric Pressure
D3670 Guide for Determination of Precision and Bias of Methods of Committee D22
D3685/D3685M Test Methods for Sampling and Determination of Particulate Matter in Stack Gases
D3796 Practice for Calibration of Type S Pitot Tubes
E1 Specification for ASTM Liquid-in-Glass Thermometers
E2251 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids
2.2 ISO Standards:
ISO 5725 Precision of test methods—Determination of repeatability and reproducibility by inter-laboratory tests
ISO 9096 Stationary source emissions—Determination of concentration and mass flow rate of particulate material in
gas-carrying ducts. Manual gravimetric method
ISO 10780 Stationary source emissions—Measurement of velocity and volume flow rate of gas stream in ducts
2.3 U.S. EPA Documents:
Reference Method 1, 40 CFR 60, Appendix A Sample and velocity traverses for stationary sources
Reference Method 3A, 40 CFR 60, Appendix A Determination of oxygen and carbon dioxide concentrations in emissions from
stationary sources (instrumental analyzer procedure)
3. Terminology
3.1 For definitions of terms used in this test method, refer to Terminology D1356.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 filtration temperature—the temperature of the sampled gas immediately downstream of the filter.
3.2.2 high volume sampling—sampling at higher rates than typical in Test Methods D3685/D3685M by using larger diameter
nozzles and higher flow rates to maintain isokinetic sampling conditions.
Available from International Organization for Standardization, Casa Postals 56, CH-1211, Geneva, Switzerland.Standardization (ISO), ISO Central Secretariat, BIBC II,
Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland, http://www.iso.org.
Metals and Alloys in the Unified Numbering System. Available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428.Available from United States
Environmental Protection Agency (EPA), William Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http://www.epa.gov.
3.2.2.1 Discussion—
Nozzle sizes are typically 20 to 50 mm, with corresponding flow rates from 5 to 50 m /s.
3.2.3 hydraulic diameter, d
h
43area of sampling plane
d 5 (1)
h
perimeter of sampling plane
3.2.3 in-stack filtration—hydraulic diameter, d filtration
h
43area of sampling plane
d 5 (1)
h
perimeter of sampling plane
in the stack or duct where the filter in its filter housing is placed immediately downstream of the sampling nozzle and collects
particulate matter in the flue gas, under flue gas conditions.
3.2.4 measurement series—successive measurements carried out at the same sampling plane and at the same process conditions.
3.2.5 out-stackout-of-stack filtration—a sampling technique where the filter, in its filter housing, collects particulate matter
under controlled temperature conditions outside of the stack or duct.
3.2.6 overall blank—the sample taken in a manner identical to the flue gas test samples, except that the sampling duration is
shortened to less than 1 min.
3.2.6.1 Discussion—
The overall blank value is expressed in the same units as the measurement result (for example, mg/m ) using the average sampling
volume of the measurement series. The overall blank includes possible deposits on the filter and surfaces upstream of the filter in
contact with the sample gas.
3.2.7 particulate matter (dust)—solid particles of any shape, structure, or density dispersed in the gas phase at flue gas
temperature and pressure conditions.
3.2.7.1 Discussion—
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In accordance with the described test method, all material that may be collected by filtration under specified conditions and that
remains upstream of the filter and on the filter after drying under specified conditions are considered to be particulate matter.
However, for the purposes of some regulatory standards, the definition of particulate matter may extend to condensibles or reacted
materials collected under specified conditions (for example, specified temperature lower than the flue gas temperature).
3.2.8 sampling line—the line in the sampling plane along which the sampling points are located bounded by the inner duct wall.
3.2.9 sampling plane—the plane normal to the centerline of the duct at the sampling position.
3.2.10 sampling point—the specific position on a sampling line at which a sample is extracted.
3.2.11 weighing control procedures—quality control procedures utilized for detecting/correcting apparent mass variations due
to climatic or environmental changes between pre- and post-sampling weighing series.
3.2.11.1 Discussion—
In this procedure, control parts, which are identical to those to be weighed for dust measurement and are pretreated under the same
conditions, are used. The control parts are kept free from dust contamination.
4. Summary of Test Method
4.1 A sample stream of the gas is extracted for a measured period of time at a controlled flow rate, and the volume of gas
collected is subsequently measured. The particulate matter (dust) entrained in the gas sample is separated by a pre-weighed filter,
which is then dried and reweighed. Deposits upstream of the filter in the sampling equipment are also recovered and weighed. The
increase of mass of the filter and the deposited mass upstream of the filter plus the deposits collected upstream of the filter are
attributed to particulate matter collected from the sampled gas. The ratio of the mass of the particulate matter collected to the
volume of gas collected allows for the calculation of the flue gas particulate concentration.
4.2 Valid measurements can be achieved only when:
4.2.1 The gas stream in the duct at the sampling plane has a sufficiently steady and identifiedmeasurable velocity, a sufficient
temperature and pressure, and a sufficiently homogeneous composition;
4.2.2 The flow of the gas is parallel to the centerline of the duct across the whole sampling plane;
4.2.3 Sampling is carried out without disturbance of the gas stream, using a sharp edged nozzle facing into the stream;
4.2.4 Isokinetic sampling conditions are maintained throughout the test;
4.2.5 Samples are taken at a preselected number of stated positions in the sampling plane to obtain a representative sample for
a non-uniform distribution of particulate matter in the duct or stack.
4.2.6 The sampling train is designed and operated to avoid condensation and to be leak free;
4.2.7 Dust deposits upstream of the filter are recovered or taken into account, or both; and
4.2.8 The sampling and weighing procedures are adapted to the expected dust quantities.
5. Significance and Use
5.1 The measurement of particulate matter and collected residue emission rates is an important test method widely used in the
practice of air pollution control. Particulate matter measurements after control devices are necessary to determine total emission
rates into the atmosphere.
5.1.1 These measurements, when approved by federal or state national, state, provincial, or other regional agencies, are often
required for the purpose of determining compliance with regulations and statutes.
5.1.2 The measurements made before and after control devices are often necessary to demonstrate conformance with regulatory
or contractual performance specifications.
5.2 The collected residue obtained with this test method is also important in characterizing stack emissions. However, the utility
of these data is limited unless a chemical analysis of the collected residue is performed.
5.3 These measurements also can be used to calibrate continuous particulate emission monitoring systems by correlating the
output of the monitoring instruments with the data obtained by using this test method.
5.3.1 This test method is useful in such correlation applications when emissions are less than 20 mg/m .
5.3.2 The correlation test method is most valid when the monitoring instrumentation samples the particulate matter under the
same test conditions as this test method.
6. Interferences
6.1 Gaseous species present in stack gases that are capable of reacting to form particulate matter within the sample train can
result in positive interference.
6.1.1 Examples include the potential reaction of sulfur dioxide (SO ) to an insoluble sulfate compound in the moisture portion
of the system (such as with limestone in flue gas following a wet flue gas desulfurization system (FGDS) to form calcium sulfate
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(CaSO ) or the reaction with ammonia gas (NH ) to form ammonium sulfate (NH ) SO and the potential reaction of hydrogen
4 3 4 2 4
fluoride (HF) with glass components in the sample train with resultant collection of silicon tetrafluoride (SiF ) in the impingers.
6.1.2 Corrosion residue in rinse of metallic nozzle and metallic probe liner when used in supersaturated, acidic flue gas streams.
6.2 Volatile matter existing in solid or liquid form in the stack gas may vaporize after collection on the sample train filtration
material due to continued exposure to the hot sample stream during the sampling period. Such an occurrence would result in a
negative interference. See also Appendix X1.
6.3 Residual material existing in sample nozzle, probe, filter housing, or glassware prior to testing.
6.4 Residue present in solvent and water reagent(s).
6.5 Transient dust and material present at sampling location (platform and port) and cleanup area.
7. Requirements for Sampling Plane and Sampling Points
7.1 Representative sampling is possible when a suitable location that has sufficiently homogeneous gas velocity at the sampling
plane is available.
7.1.1 Perform sampling at a sufficient number of sampling points, which are usually located on several sampling lines.
Convenient access ports and a working platform are required for the testing. See U.S. EPA Reference Method 1, 40 CFR 60,
Appendix A, or ASTM Test Method D3685/D3685M for additional criteria.
7.2 Sampling Plane:
7.2.1 The sampling plane shall be situated in a length of straight duct (preferably vertical) with a constant shape and constant
cross-sectional area. The sampling shall be conducted as far downstream and upstream from any obstruction that may cause a
disturbance and produce a change in the direction of flow (disturbances can be caused by bends, fans, or control equipment). The
sampling plane location shall maximize the distance downstream from a flow disturbance.
7.2.2 Measurements at all the sampling points defined in 7.3 shall prove that the gas stream at the sampling plane meets the
following requirements:
7.2.2.1 The angle of gas flow is less than 15° with regard to the duct axis (method for estimation is indicated in Annex C of
ISO 10780);
7.2.2.2 No local negative flow is present;
7.2.2.3 The minimum velocity is measurable by the test method used (for example, using Test Method D3154, a differential
pressure larger than 5 Pa); Pa (0.02 in. H O)); and
7.2.2.4 The ratio of the highest to lowest local gas velocities is less than 3:1.
7.2.3 If the above requirements cannot be met, the sampling location will not be in compliance with this test method.
7.3 Minimum Number and Location of Sampling Points:
7.3.1 See Test Method D3154, Section 8, Figs. 7 and 8, and Tables 1 and 2.
7.4 Access Ports:
7.4.1 Provide sampling ports for access to the sampling points selected, in accordance with 7.3 and Test Method D3154.
7.4.2 Ensure that the port dimensions offer ample space for the insertion and removal of the sampling equipment and associated
devices.
7.4.3 Sample ports must be clean and free of debris, and allow for clean access/egress of the sample nozzle and probe.
8. Velocity and Gas Composition Measurement Apparatus
8.1 See Section 6, Test Method D3154.
9. Sampling Apparatus and Equipment
9.1 Sampling Train—For schematic drawings of the major sampling train components refer to Fig. 1 for the in-stack method
and Fig. 2for the out-of-stack method.
FIG. 1 In Stack Out-of-Stack Sampling Train—Example of a Dry Basis Measurement System
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9.1.1 The materials of construction of in-stack and certain out-of-stack components (such as the nozzle, probe, unions, filter
holder, gaskets, and other seals) shall be constructed of materials that will withstand corrosive or otherwise reactive components
or properties of the stack or gas stream, or both. Recommended materials for a normal range of stack and sample conditions include
PFTE fluoro hydrocarbons PTFE fluoroplastic (up to 175°C), 316 stainless steel (up to 800°C), and some resistant silicone
materials (up to 150°C). Extreme temperature conditions may require the use of materials such as quartz or a nickel-chromium
alloy, or a water-cooled probe may be used.
9.2 Elements of the Sampling Train—The sampling train for collecting particulate matter and collected residue from a gas stream
flowing through a stack consists of the following interconnected elements:
9.3 Nozzles—The first part of the sampling equipment to encounter the dust or moisture-laden gas stream, or both, is the nozzle.
To extract a representative sample of gas and particulate matter, the nozzle used for sampling shall be within a narrow range of
inside diameters.
9.3.1 The probe nozzle is provided with a sharp, tapered leading edge and is constructed of either glass, virgin seamless 316
stainless steel tubing or glass tubing, or other virgin corrosion-resistant metal or material that is appropriate for the temperature
of the gas to be sampled formed in a button-hook or elbow configuration. The tapered angle shall be <30°C<30° with the taper
on the outside to establish a constant inside diameter (ID). The straight length from the nozzle opening to the first bend of the
nozzle shall be greater than 30 mm. Glass nozzles should be used whenever possible and especially in wet, corrosive gas streams.
9.3.2 A range of nozzle IDs, for example, 3 to 15 mm (0.125 to 0.5 in.), in increments of 1.5 mmm are required for isokinetic
sampling. Larger nozzle sizes may be required if high volume sampling trains are used or if very low flows are encountered. Inspect
the nozzle before use for roundness and for damage to the tapered edge, such as nicks, dents, and burrs. Do not use a damaged
nozzle. Check the diameter with a micrometer or other acceptable measuring device. A slight variation from exact sizes should be
expected due to machining tolerances. Engrave each nozzle with an identification number for inventory and calibrating purposes.
9.4 Filter Holders: Holders and Heating:
9.4.1 In-Stack Method: A filter holder constructed of borosilicate or quartz glass. Use a glass/silicone rubber or TFE-
fluorocarbon frit to support the filter inside the filter holder. The holder shall be durable, easy to load, and leak free in normal
applications. It is recommended to perform the following leak check procedure prior to using a new filter holder assembly to ensure
that each filter holder is able to be assembled in a leak-free manner. This leak check procedure is not intended to be used for pretest
and posttest leak checks of the sampling system.
9.4.1.1 Thimble Holder—A stainless steel holder for the porous aluminum oxide thimble (see 10.9). Holders for a glass and glass
fiber thimble are somewhat different in design and method of retention. Keep the overall diameter to a minimum to facilitate
insertion of the entire holder through a relatively small (75 mm) sampling port. The holder provides a method for clamping the
thimble firmly in position with its lip pressed against a soft gasket. The gasket sealing together the cap and housing of the holder
is made of a compressible material, such as stainless steel or TFE-fluorocarbon ferrules, that will provide an adequate seal at the
desired temperature. Such holders and the thimbles can withstand temperatures approaching 550°C. If porous aluminum oxide
thimbles are used, take care to avoid any spalling or crushing of the thimble lip in assembling and disassembling the thimble in
its holder as the tare mass is critical to the determination of the test results. Other designs, such as nozzle/filter holder combinations
that are weighed as a single unit, may be used if the performance characteristics of this test method can be met in their use.
(1) Assemble the filter holder and filter.
(2) Perform the standard leak check at 50 kPa vacuum at ambient temperature. A leakage rate of 570 mL/min is allowed;
however, under these laboratory conditions, the entire train shall be leak-less.
(3) Place the filter holder in an oven (a method filter heater compartment can be used) at about 100°C for about 30 min. Perform
the leak check with the filter holder in the oven. The filter holder shall again remain leak-less.
(4) Remove the filter holder from the oven and cool for 30 min. Again run the leak check.
(5) Elevate the temperature of the oven to the maximum temperature expected during the test. Place the filter holder in the
oven, and heat it for 30 min. Repeat the leak test.
(6) Remove the filter holder and allow it to cool for 30 min. Run the final leak check. If the filter holder passes these leak check
procedures, then it is properly designed to remain leak free when properly maintained.
(7) If the filter holder passes the leak checks at the lower temperatures, but not the maximum temperature, replace the filter
holder.
(8) If the filter holder is unable to pass the leak check procedure at 100°C, reject the holder unless sampling is to be performed
only at ambient temperature.
9.4.1.2 Alternate Filter Holder/Backup Filter Holder—An in-stack filter holder constructed of borosilicate or quartz glass or
stainless steel. Use a silicone rubber, TFE-fluorocarbon, or stainless steel gasket. The holder shall be durable, easy to load, and leak
free in normal applications. It is positioned immediately following the nozzle (but greater than 50 mm from the nozzle) with the
filter placed toward the flow. Perform the following leak check prior to use to ensure that each filter holder is properly assembled.
(1) Assemble the sample probe, filter holder, and filter with the exception that a steel plug is used in place of the nozzle to
provide a leakless seal.
(2) Perform the standard leak check at 50 kPa vacuum at ambient temperature. A leakage rate of 570 mL/min is allowed;
however, under these laboratory conditions, the entire train shall be leak-less.
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(3) Place the filter holder in an oven (an out-of-stack method filter heater compartment can be used) at about 100°C for about
30 min. Perform the leak check with the filter holder in the oven. The filter holder shall again remain leak-less.
(4) Remove the filter holder from the oven and cool for 30 min. Again run the leak check.
(5) Elevate the temperature of the oven to the maximum temperature expected during the test. Place the filter holder in the
oven, and heat it for 30 min. Repeat the leak test.
(6) Remove the filter holder and allow it to cool for 30 min. Run the final leak check. If the filter holder passes these leak check
procedures, then it is properly designed to remain leak free when properly maintained.
(7) If the filter holder passes the leak checks at the lower temperatures, but not the maximum temperature, replace the filter
holder.
(8) If the filter holder is unable to pass the leak check procedure at 100°C, reject the holder unless sampling is to be performed
only at ambient temperature.
9.4.2 Filter Heating System—A heating system capable of maintaining the filter holder at the specified filtration temperature
68°C during sampling.
9.4.3 Filter Thermometer—Monitoring device for measuring temperature inside the filter holder to within 1°C during sampling.
9.4.4 Out-of-Stack Method Filter Holder—Refer toBefore sampling, 9.4.1 for in-stack method details. check the heating system
and the temperature monitoring device. It is important that the heating element be easily replaceable in case of a malfunction during
sampling.
9.4.2.1 Filter Heating System—A heating system capable of maintaining the filter holder at 120 6 15°C during sampling. Other
temperatures may be specified for a particular application.
9.4.2.2 Filter Thermometer—Monitoring device for measuring temperature of the filter holder to within 3°C during sampling.
9.4.2.3 Before sampling, check the heating system and the temperature monitoring device. It is important that the heating
element be easily replaceable in case of a malfunction during sampling.
9.5 Probes:
9.5.1 Probe Extension (In-Stack Method)—Any rigid probe extension may be used. Its diameter shall be sufficient to provide
adequate stiffness for support at the greatest distance within the stack. Check the probe extension visually for cracks or breaks and
for leaks on a sampling train (see Fig. 2). This includes a proper leak-free connection from filter holder to probe. The probe
extension shall be constructed of stainless steel when non-corrosive gases are present during testing. Use a heated glasslined probe
when corrosive or condensible material is present in the stack. Otherwise, the condensed or corroded materials in the probe
extension may drain or be back flushed into the filter and contaminate the sample. Use a nonreactive material to prevent
contamination of the sample if condensibles are to be retained. Use probe extenders of nickel-iron-chromium alloy (UNS N08825)
(see DS 56I ) or equivalent at temperatures greater than 315°C. (Record the probe material selection in the field data sheet.)
9.5.1 Out-of-Stack Method—The sampling probe liner shall be constructed of borosilicate or quartz glass corrosion-resistant,
seamless tubing with an outside diameter (OD) of about 16 mm, usually encased in a within a heating system within a stainless
steel sheath with an OD of 25 mm. A larger-diameter sheath or over-sheath may be used. Whenever practical, use borosilicate or
quartz glass liners; alternatively, metal seamless liners of 316 stainless steel, a nickel-chromium alloy, nickel-iron-chromium alloy
(UNS N08825) (see DS 56IN08825), titanium or titanium alloy (see DS 56I6 ), or other corrosion resistant metals metal or material
that is appropriate for the temperature of the stack being sampled may be used. A heating system that will maintain an exit gas
temperature of 120 6 14°C8°C (250 6 25°F)15°F) during sampling is required. required except when the temperature of the stack
is high enough to maintain such a temperature without a heating system. Other temperatures may be specified for a particular
application. application, but the heating system must maintain 68°C. Use either borosilicate or quartz glass liners for stack
temperatures up to about 480°C (900°F), but use quartz glass liners from 480 to 900°C. Either type of liner may be used at higher
temperatures for short time periods. However, do not exceed the absolute upper limits, that is, the softening temperatures of 820°C
and 1500°C for borosilicate and quartz, respectively. If metal or other material is used, do not exceed the softening or degradation
temperature specific to that material. Metal probe liners should be heat-treated or baked at 350°C or higher before first use to aid
in removal of oils used in manufacture, as solvent cleaning will not always remove those oils from the inner surface of the metal
tubing. It is recommended that metal liners be of virgin material having never been used on any other source emissions test. Metal
probe liners used in wet acidic gas streams have been documented to have a significant contribution of corrosion byproducts in
the particulate catch sample. When using metal probe liners, the source emission tester, source owner, or regulatory agency should
consider conducting a test to prove the metal liner material will not contribute significantly to the particulate sample under the stack
gas conditions. Visually check new probes for breaks or cracks and for leaks on a sampling train. This includes a proper
nozzle-to-probe connection with a fluoroelastomer O-ring or TFE-fluorocarbon ferrules. Check the probe heating system
connection. Check the probe heating system prior to conducting a test program as follows:
9.5.2.1 Connect the probe with a nozzle attached to the inlet of the vacuum pump (see 9.10.3).
9.5.1.1 Electrically connect and turn on the probe heater for 2 or 3 min. The probe should become warm to the touch.
D6331 − 16
9.5.1.2 After the probe temperature reaches equilibrium record the probe temperature. Rotate the probe one quarter turn inside
the sheath and record the probe temperature after one minute. Rotate the probe one quarter turn two more times inside the sheath
recording the probe temperature after one minute at each spot. Average the four probe temperature readings. The probe temperature
readings taken at each quarter turn shall not vary by more than 5°C from the average probe temperature; otherwise, reject or repair
the probe heating system.
9.5.1.3 Connect the probe with a nozzle attached to the inlet of the vacuum pump (see 9.10.3).
9.5.1.4 Activate the pump and adjust the needle valve until a flow rate of about 20 L/min is achieved.
9.5.1.5 Be sure the probe remains warm to the touch and the probe heater is capable of maintaining the exit air temperature at
a minimum of 100°C.120°C. Otherwise, reject or repair the probe.
9.6 Condenser—Four impingers connected in series and immersed in an ice bath with leak-free ground-glass fittings or any
similar noncontaminating fittings.
9.6.1 The first, third, and fourth impingers shall be the Greenburg-Smith design modified by replacing the inserts with a glass
tube that has an unconstricted 13-mm ID and that extends to within 13 mm of the flask bottom. If no analysis of the collected
residue is to be performed on the impinger catch, use of glass impingers is not required as long as the gas moisture content is
determined by alternate means (see Test Method D3154).
9.6.1.1 If no analysis of the collected residue is to be performed on the impinger catch, use of glass impingers is not required
as long as the gas moisture content is determined by alternate means (see Test Method D3154).
9.6.2 The second impinger shall be a Greenburg-Smith with the standard tip and plate. Modifications (for example, using
flexible connections between impingers, materials other than glass, or a flexible vacuum hose to connect the filter holder to the
condenser) may be used.
9.6.3 The fourth impinger outlet connection shall allow for insertion of a thermometer (see 9.6.5). Alternatively, any system that
cools the gas stream and allows measurement of the condensed water and the water vapor leaving the condenser, each to within
1 mL or 1 g, may be used.
9.6.4 Test the standard Greenburg-Smith impinger by filling the inner tube with water. If the water does not drain through the
orifice in 6 to 8 s or less, replace the impinger tip or enlarge it to prevent an excessive pressure drop in the sampling system. Check
each impinger visually for damage, including breaks, cracks, or manufacturing flaws, such as poorly shaped connections.
9.6.5 Impinger Thermometer—Monitoring device for measuring temperature of gas exiting the fourth impinger (see 9.6.3)
within 61°C of true value in the range from 0 to 25°C.
9.7 Gas Temperature Sensor—For measuring gas temperature to within 61°C. Permanently attach the temperature sensor to
either the probe (see 9.5) or the pitot tube (see 9.9 and Figs. 1 and 2Fig. 1).
9.8 Vacuum Lines—Locate all components of the sampling system as close together as possible, with direct interconnection
between successive components in the system wherever possible. When direct interconnection is not possible, all vacuum (gas
sampling) lines shall be of smooth-bore, inert material capable of withstanding internal and external temperatures at the sampling
location and of withstanding a vacuum of 65 kPa without collapse or leakage.
9.9 Pitot Tube—The pitot tube, Type S design, meeting the requirements of Test Method D3154, shall be used. Attach the pitot
tube to the probe as shown in Fig. 21. Visually inspect the pitot tube for both vertical and horizontal tip alignments. If the tube
is purchased as an integral part of a probe assembly, check the dimensional clearances. Repair or return any pitot tube that does
not meet specifications. Calibrate the Type S tube following the procedures given in Practice D3796.
9.10 Metering System—The metering system, consisting of two vacuum gages, a vacuum pump, a dry gas meter with 2 %
accuracy at the required sampling rate, thermometers capable of measuring 63°C61°C of true value in the range from 0 to 90°C,
pressure gage, check valves, and related equipment, as shown in Figs. 1 and 2Fig. 1. Other metering systems capable of
maintaining sampling rates within 10 %5 % of isokinetic and of determining sample volumes to within 2 % may be used. Upon
receipt or after construction of the equipment, perform both positive and negative pressure leak checks before beginning the system
calibration procedure, as described in Test Methods D3685/D3685M. Any leakage requires repair or replacement of the
malfunctioning item. Components include the following:
9.10.1 Differential Pressure Gage—Two inclined manometers or the equivalent, as specified in Test Method D3154. One (called
the pitot manometer) is utilized to monitor the stack velocity pressure, and the other (called the orifice meter) to measure the orifice
pressure differential. Initially, check the gages against a gage-oil manometer at a minimum of three points: 5, 125, and 250 Pa. The
gages shall read within 5 % of the gage-oil monometer at each test point. Repair or reject any gage that does not meet these
requirements
9.10.2 Dry Gas Meter—A volume meter is required for measuring the total sample flow for each test. A calibrated dry gas test
meter (2 % accuracy at a flow rate of 20 L/min) is the most satisfactory totalizing volume meter available for source test work.
Calibrate the meter in the laboratory prior to use with a positive displacement liquid meter, and determine the correction factor as
necessary.
9.10.2.1 Dry Gas Meter Thermometer—Two monitoring devices for measuring temperature to within 3°C1°C in the range from
0 to 90°C of the gas entering and exiting from the dry gas meter (see 9.10.2).
D6331 − 16
9.10.3 Vacuum Pump—An airtight, leak-free vacuum pump with coarse and fine flow controls capable of maintaining a flow rate
of 20 L/min for a pump inlet vacuum of 50 kPa is used to draw the gas sample.
9.10.4 Vacuum Gauge, for measuring pressure at the vacuum pump inlet, capable of measuring 63 kPa over the range from 0
to 101 kPa. Check it against a mercury U-tube manometer upon receipt, and yearly thereafter.
9.11 Nomograph, to determine the isokinetic sampling. Its function may be applied with a hand-held programmable calculator
or laptop computer.
9.12 Thermometers—Temperature measuring devices such as RTDs, thermistors, and organic liquid-in-glass thermometers
meeting rthethe requirements of specific applications may be used. ASTM thermometers, S59C and S63C as identified in
Specification E2251, may be substituted for thermomenters 59C and 63C directly. In addition, precision digital thermometers based
on resistance temperature detectors (RTDs), thermistors, or thermocouples, or organic liquid-in-glass thermometers with equivalent
or better accuracy and precision in the appropriate temperature range may be used. See Test Methods D3685/D3685M for
calibration procedures.
9.13 Barometer—An aneroid, or other barometer capable of measuring atmospheric pressure to within 6300 Pa shall be used.
Calibrate the barometer against a mercury-in-glass barometer or the equivalent, as described in Test Method D3631.
9.13.1 Alternatively, the absolute barometric pressure may be obtained from a nearby weather service station and adjusted for
elevation difference between the station and the sampling point. Either subtract 10 Pa/m from the station value for an elevation
increase or add the same for an elevation decrease. Replace the barometer if it cannot be adjusted to agree within 300 Pa of the
reference barometric pressure.
9.14 Wet Test Meter, with a capacity of 3.5 m /h or 30 L for each revolution with an accuracy of 61.0 %, to calibrate the dry
test meter.
9.15 Orsat Gas Analyzer, Analyzer or equivalent instrumental analysis of O and CO , stack gas analyzer, as described in Test
2 2
Method D3154. or U.S. EPA Reference Method 3A, 40 CFR 60, Appendix A.
9.16 U-Tube Manometer, a water manometer or pressure sensor capable of measuring gas pressure to within 0.33 kPa.
9.17 Sample Recovery Apparatus:
9.17.1 Probe Liner and Nozzle Brushes, nylon bristle brush with a stainless steel wire handle or PTFE/nylon tube handle as long
as the probe, and a separate smaller and very flexible brush for the nozzle may be used. At a minimum use a new probe and nozzle
brush for each test program.
9.17.2 Wash Bottles, two 500-mL wash bottles for probe and glassware rinsing. Glass bottles are preferred, but polyethylene is
acceptable; however, if polyethylene is used, do not store the acetone in polyethylene wash bottles for longer than a month. or
PTFE squeeze bottles are required.
9.17.3 Sample Storage Container, 500 or 1000-mL chemically resistant, borosilicate glass bottles for storage of acetone rinses,
with leak-proof screw caps with leak-proof, rubber-backed TFE-fluorocarbon cap liners. Wide-mouthed bottles are easiest to use,
but narrow mouth bottles are less prone to leakage. As an alternative to glass, polyethylene bottles may be used, if the storage time
is short. Precleaned glass bottles are recommended. Inspect the cap seals and the bottle cap seating surfaces for chips, cuts, cracks,
and manufacturing deformities that would permit leakage.
9.17.4 Petri Dishes, glass or polyethylene glass, polyethylene, styrene, or similar material petri dishes for storage and for
transportation of the filter and collected sample.
9.17.5 Graduated Cylinder or Cylinder, Triple Beam Balance, or Both, Electronic Scale, a graduated cylinder or cylinder, a
triple beam balance balance, or electronic scale to measure the water condensed in the impingers during sampling. The graduated
cylinder may be used to measure water initially placed in the first and second impingers. In either case, the required accuracy is
1 mL or 1 g; therefore, use a cylinder with subdivisions of ≤2 mL. Use a triple beam balance capable of weighing to the nearest
1.0 g.
9.17.6 Plastic Storage Containers, several airtight plastic containers for storage of silica gel.
9.17.7 Funnel and Rubber Policeman—A funnel and rubber policeman to transfer the used silica gel from the impinger to a
storage container unless silica gel is weighed in the field after the test.
9.17.8 Desiccator, used to dry filters before weighing. Use anhydrous CaSO (see 10.5) as the desiccant.
9.17.9 Laboratory Drying Oven, capable of heating filters and thimbles rinse solution containers to 102°C.
9.17.10 Laboratory Muffle Furnace, capable of heating thimbles to 550°C.
9.17.11 Steam Bath:
9.18 Analytical Equipment:
9.18.1 Glassware, Weighing Dishes, borosilicate glass dishes polyethylene petri dish or other low tare weight container to
facilitate filter weighing. Use a 250-mL glass beaker PTFE beaker insert or equivalent low tare weight weighing dish for
evaporation of the acetoneacetone/water rinse.
9.18.2 Balance, analytical grade, capable of weighing the filter and the sample beaker to within 60.1 mg.
D6331 − 16
10. Reagents and Materials
10.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. All reagents shall conform to the specifications of
the committee on Analytical Reagents of the American Chemical Society.
10.2 Purity of Water—Unless otherwise specified, water shall be Type III reagent water conforming to Specification D1193.
NOTE 1—Type IV reagent water is required in 11.4.2.
10.3 Determine reagent blanks on the acetone and reagent water.
10.4 Acetone—Reagent ACS grade acetone with ≤ 0.001 % ≤0.001 % residue in glass bottles. Acetone supplied in metal
containers is unacceptable due to the prevalently high residue levels. Reject the acetone if blank residue mass (see 10.3) is
>0.001 % of the total acetone mass.
10.5 Calcium Sulfate, Anhydrous—CaSO , indicating type, for wasuse in desiccator.
10.6 Crushed Ice.
10.7 Silica Gel—SiO , indicating-type, 6 to 16-mesh, for use in the fourth impinger in the condenser. Dry at 175°C for at least
2 h prior to use.
10.8 Gloves, insulated, heat-resistant.
10.9 Filter Material:
10.9.1 In-Stack Method—The primary filter is generally a porous aluminum oxide glass, or glass-fiber thimble. For heavy dust
loading applications, such as sampling stacks without control equipment or sampling on the inlet side of the control equipment.
A secondary filter for back-up may be used (see 10.9.2). Procedures for filter preparation are given in 11.1.1 and 11.1.2.
10.9.1 Alternate In-stack Method A and Out-of-Stack Method—Use glass fiber filters without organic binders. Quartz glass fiber
filter are recommended for use in most applications (especially in gas streams with SO or other acid gases). However other filter
materials (for example, PTFE, polycarbonate, ceramic, or cellulose) may be used provided the stack tester or source owner can
demonstrate the filter material will not bias the results due to chemical reaction between the filter material and the effluent gas
matrix. The filters shall exhibit at least 99.95 % collection efficiency of a 0.3-mm dioctyl phthalate smoke particle, in accordance
with Practice D2986. The manufacturer’smanufacturer’s quality control test data are sufficient for validation of efficiency. Check
the filters for irregularities, flaws, or pinholes by holding them up against a light source.
10.9.2.1 Check the filters for irregularities, flaws, or pinholes by holding them up against a light source.
11. Weighing and Pre-Sampling Procedure
11.1 General Aspects—Before carrying out any measurements, discuss the purpose of the sampling and the sampling procedures
with the plant personnel concerned. The nature of the plant process, for example, steady state or cyclic, can affect the sampling
program. If the process can be performed in a steady state, it is important that this state is maintained during sampling
NOTE 1—There may be regulatory requirements for the state of plant operations and you may wish to consult with regulatory personnel as well.
11.1.1 Agree upon, with the plant management, the dates, starting times, duration of survey, and sampling periods as well as
plant operating conditions during these periods.
11.1.2 Make preliminary calculations on the basis of the expected dust loading to determine the appropriate nozzle size or
sampling conditions, or both. Also determine whether the chosen nozzle size and sampling time will result in sufficient particulate
matter collected to meet weighing requirements. Longer sampling times or sampling with the use of a larger nozzle and higher
sample flow rates may be necessary to obtain the sample filter mass sufficiently greater than the blank filter mass.
11.1.3 Discussion—To obtain results with 10 percent uncertainty at 0.99 confidence and a reported lab detection limit (DL) of
0.15 mg, one needs to collect 5.0 mg in the sampling system:
~DL * 100!⁄3
At a particulate concentration of 5 mg/scm and sampling at 1.0 standard cubic foot per minute (0.028 standard cubic metres per
minute), the sampling time needs to be approximately 36 minutes.
11.2 Taking into account the objective of the measurements and the flue gas characteristics:
11.2.1 Choose between an in-stack or an out-stack filtration device. If the flue gas is satura
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