ASTM D6327-10(2016)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D6327 − 10 (Reapproved 2016)
Standard Test Method for
Determination of Radon Decay Product Concentration and
Working Level in Indoor Atmospheres by Active Sampling
on a Filter
This standard is issued under the fixed designation D6327; 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 1.6 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
1.1 This test method provides instruction for using the grab
standard.
sampling filter technique to determine accurate and reproduc-
1.7 This standard does not purport to address all of the
ible measurements of indoor radon decay product (RDP)
safety concerns, if any, associated with its use. It is the
concentrationsandoftheworkinglevelvaluecorrespondingto
responsibility of the user of this standard to establish appro-
those concentrations.
priate safety and health practices and determine the applica-
1.2 Measurementsmadeinaccordancewiththistestmethod
bility of regulatory limitations prior to use. See Section 9 for
will produce RDP concentrations representative of closed-
additional precautions.
building conditions. Results of measurements made under
2. Referenced Documents
closed-building conditions will have a smaller variability and
are more reproducible than measurements obtained when
2.1 ASTM Standards:
buildingconditionsarenotcontrolled.Thistestmethodmaybe
D1356Terminology Relating to Sampling and Analysis of
utilized under non-controlled conditions, but a greater degree
Atmospheres
of variability in the results will occur. Variability in the results
D1605Practices for Sampling Atmospheres for Analysis of
may also be an indication of temporal variability present at the
Gases and Vapors (Withdrawn 1992)
sampling site.
D3631Test Methods for Measuring Surface Atmospheric
Pressure
1.3 Thistestmethodutilizesashortsamplingperiodandthe
E1Specification for ASTM Liquid-in-Glass Thermometers
results are indicative of the conditions only at the place and
time of sampling. The results obtained by this test method are
3. Terminology
not necessarily indicative of longer terms of sampling and
3.1 Definitions—For definitions of terms used in this test
should not be confused with such results. The averaging of
method, refer to Terminology D1356.
multiple measurements over hours and days can, however,
provide useful screening information. Individual measure-
3.2 Definitions of Terms Specific to This Standard:
ments are generally obtained for diagnostic purposes.
3.2.1 grab sampling—the act and all procedures involved
with obtaining a short term sample through the use of an
1.4 The range of the test method may be considered from
operating air pump.
0.0005 WL to unlimited working levels (WL), and from 40
3.2.2 radon—the particular isotope Radon-222.
Bq/m to unlimited for each individual randon decay product.
3.2.3 radon decay products (RDP)—any or all of the par-
1.5 This test method provides information on equipment,
ticular isotopes polonium-218, bismuth-214, lead-214, and
procedures, and quality control. It provides for measurements
polonium-214.
within typical residential or building environments and may
3.2.4 working level—quantity of short-lived decay products
not necessarily apply to specialized circumstances, for
that will result in 1.3 × 10 MeV of potential alpha energy per
example, clean rooms.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This test method is under the jurisdiction of ASTM Committee D22 on Air contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Quality and is the direct responsibility of Subcommittee D22.05 on Indoor Air. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved April 1, 2016. Published April 2016. Originally the ASTM website.
approved in 1998. Last previous edition approved in 2010 as D6327–10. DOI: The last approved version of this historical standard is referenced on
10.1520/D6327-10R16. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6327 − 10 (2016)
litre of air. The working level is the common unit for 7. Apparatus
expressing environmental RDP exposure.
7.1 Collection Apparatus:
7.1.1 Air pump capable of 10 to 12 L/min flow rate.
4. Summary of Test Method
7.1.2 Bubble tube airflow calibration cell, 1 L or larger.
7.1.3 Calibrated dry gas meter.
4.1 Grab sampling measurements of RDPconcentrations in
7.1.4 Flow meter (optional).
airareperformedbycollectingtheRDPfromaknownvolume
7.1.5 Open-faced filter holder, 25 or 47-mm diameter.
of air on a filter and subsequently counting the activity on the
7.1.6 Membrane filters, mixed cellulose ester, 25 or 47-mm
filter following collection. The counting is performed at
diameter, 0.8-µm pore size.
specified times for specified periods. The energy from radio-
7.1.7 Sharpened forceps, for removal of sample filters.
active decay of the particles collected on the filter is converted
7.1.8 Stopwatch, accurate to 1 s.
to light pulses by a zinc sulfide phosphor in contact with the
filter. The light pulses are detected and converted to counts.
7.2 Decay Counting Apparatus:
Analysis of the number of counts in each counting interval
7.2.1 Zinc sulfide phosphor discs, 51-mm diameter.
determines the concentrations of the RDP. The two counting
7.2.2 Scintillation Counter, scaler and photomultiplier tube.
methods which have found the most general use are the
7.2.3 High voltage power supply.
Kusnetz and the modified Tsivoglou procedures.
7.3 Thermometer (see Specification E1).
7.4 Barometer (see Test Methods D3631).
5. Significance and Use
5.1 Thetestmethodprovidesarelativelysimplemethodfor
8. Reagents and Materials
determinationoftheconcentrationofRDPwithouttheneedfor
8.1 National Institute of Standards and Technology (NIST)
specialty equipment built expressly for such purposes.
traceable alpha calibration source, typically americium-241, to
7,8
5.2 Using this test method will afford investigators of radon
determine counter efficiency.
indwellingsatechniquebywhichtheRDPcanbedetermined.
The use of the results of this test method are generally for
9. Hazards
diagnosticpurposesandarenotnecessarilyindicativeofresults
9.1 Since radioactive material is being utilized, both in the
that might be obtained by longer term measurement methods.
form of calibration standards and particles collected on sample
5.3 Animprovedunderstandingofthefrequencyofelevated filters, wear disposable gloves during handling of these items.
radon in buildings and the health effect of exposure has
9.2 Iftheatmospheresbeingmeasuredareknowntocontain
increased the importance of knowledge of actual exposures.
high concentrations of RDP, wear an HEPA half-mask respi-
The measurement of RDP, which are the direct cause of
rator during sampling.
potential adverse health effects, should be conducted in a
9.3 The calibration source from NIST must be shielded
manner that is uniform and reproducible; it is to this end that
when not being used for calibration. Shield the source by
this test method is addressed.
returningthesourcetotheoriginalNISTstoragecontainerand
placing the source in the original storage geometry within the
6. Interferences
container.
6.1 Interferences may be caused by any alpha-emitting
particle capable of inducing a light pulse in the phosphor
10. Preparation of Apparatus
screen used for alpha-counting. In general, the only significant
10.1 Verify proper operation of the equipment prior to
interference source is that of the decay products of radon-220,
collection of the sample. Refer to equipment manuals for
thoron, which may be considerable in certain geographical
information.
regions. The direction of the interference is always positive.
10.1.1 Operate each counting system at the high-voltage
The extent to which thoron decay products interfere can be
(HV) and threshold settings that combines maximum stability,
estimated or measured through alpha-spectroscopy or serial
good counting efficiency, and low background counts. Each
type measurements.
manufacturer’s counting systems have different set-up require-
6.2 Some depth penetration to the filter may occur. The
ments and optimization procedures. A general similar proce-
extent of the penetration may be estimated using membrane
dure is available.
filtertypesnotsuggestedwithinthistestmethod.Thedirection
of interferences is always negative.
Interlaboratory Radon-Daughter Measurement Comparison Workshop: 9-12
September 1985, GJ/TMC-25 UC-70A, United States Department of Energy,
Washington D.C. [Available through: NIST, National Technical Information
Thomas,J.W.,“MeasurementofRadonDaughtersinAir,” Health Physics,Vol Service, United States Department of Commerce, Springfield, VA 22161].
23, 1972, p. 783. Available from: NIST Standard Reference Materials Catalog, NIST Special
Indoor Radon and Randon Decay Product Measurement Protocols, EPA Publication 260, U.S. Department of Commerce, Nation Institute of Standards and
402–R–92–004, July 1992, United States EnvironmentalAgency,Washington, D.C. Technology 1990-1991, Issued January 1990, as Catalog SRM No. 4904NG.
6 9
Measurement of Radon and Radon Decay Products in Air, NCRP Report No. StandardTestMethodforRadonGrabSampling,Revision02,March31,1992;
97, National Council on Radiation Protection and Measurements, Bethesda, MD GJ/TMC Technical Procedure RN-GRAB-U, United States Department of Energy,
20814, Nov. 15, 1988. Washington D.C.
D6327 − 10 (2016)
10.2 Determine the counter efficiency and background for 11.2.2 Place a fresh phosphor disc at the center of the
the sampling filter and phosphor screen pair prior to collection photomultiplier lens. Select a sampling filter with the forceps,
of the sample (see Section 11). andinspectthefiltertodetermineifanytearsarepresent:ifso,
discard.Placeanacceptablesamplingfilterontopatthecenter
10.3 The air pump, filter assembly, and connecting tubing
of the phosphor disc, making sure the sampling surface is
shall not leak.
towardthephosphordisc.Securethefiltertothephosphordisc,
10.4 A volume meter is needed for measuring total sample
and ensure complete contact by placing a flat cover plate over
flow. A calibrated dry gas test meter is the most satisfactory
the filter. The cover plate shall completely cover the filter and
totalvolumemeteravailableforsourcetestwork.Calibratethe
have been previously checked to ensure no count contribution.
meter in the laboratory prior to use with a positive displace-
11.2.3 Obtain a count measurement for 10 min. For every
ment liquid meter or a cylinder and piston flow calibrator, and
set of measurements, utilize a phosphor disc that no longer
determine a meter correction factor, C , as necessary.
M
shows enhanced activity from previous sampling measure-
10.5 Locate the scintillation counter to provide rapid access
ments. Use the same phosphor disc for a filter before and after
from the sampling site when the modified Tsivoglou counting collection of a sample with the filter. If the total count for 10
procedureisutilized.Thisprocessisnecessaryduetotheshort min is greater than 10, replace the filter and phosphor disc pair
time period between sampling and the start of counting. and recount. The number is the background count, B, and is
recorded in counts.
11. Procedure
11.2.4 Remove the filter from the phosphor disc with the
forceps and place in the filter holder with the counted side
11.1 Calibration of Scintillation Counter:
exposed to the air.
11.1.1 Determine the efficiency of the scintillation counter
11.2.5 Reassemble the filter holder with care to prevent
through use of the NIST-traceable alpha-emitting calibration
tearing of the filter.
point source.
11.1.2 Deactivate the photomultiplier tube. Exposure of an 11.2.6 Obtain the initial dry gas meter reading.
activated photomultiplier tube to light while connected to
11.2.7 Draw sample air through the filter for 5.00 min.
power may permanently damage the photomultiplier tube.
11.2.8 Obtain the final dry gas meter reading and record the
volume of air sampled in litres, V.
NOTE 1—Although comments have been received indicating any light
incident on the deactivated photomultiplier tube, even though completely
11.2.9 Disassemble the filter holder, and carefully transfer
disconnectedfrompower,willresultinspuriousaddition/deletionsoflight
the filter from the filter holder onto the phosphor disc with
pulses. Tests conducted with four photomultiplier tubes of two designs at
which the background was just previously measured (exposed
the Grand Junction DOE Facility Radon Chamber indicated no variation
sample filter side oriented toward the phosphor disc). During
in background counts from photomultiplier tubes kept in the dark versus
thetransfer,inspectthefilterfortears.Ifatearisfound,discard
the same tubes with large mercury arc lamps over the tubes.
and begin again. Cover the filter with the cover plate. Cover
11.1.3 Place a fresh phosphor disc (phosphor side up) at the
and reactivate the photomultiplier tube.
center of the photomultiplier lens.
11.1.4 Cover and activate the photomultiplier tube. The
11.3 Sample Counting—Two different counting techniques
photomultiplier shall not be opened to light while activated or
are described in this section, a modified Tsivoglou Technique
the electronics will be shocked. It is very important that there
(see 11.3.1) and a Kusnetz Technique (see 11.3.2). Each
be no power to the opened photomultiplier.
technique requires a unique set of counting intervals.
11.1.5 Activate the scintillation counter for a defined count-
Additionally, each technique requires a separate set of calcu-
ing interval in minutes, C. The counting interval shall be long
lations as listed in Section 12.
I
enoughtoobtainatleast10000countsfromthealpha-emitting
11.3.1 Modified Tsivoglou Technique—Operatethescintilla-
source. The number of counts obtained from the phosphor is
tion counter for the following time intervals. The intervals are
the background count, B .
cal
measured from the time the 5.00 min sampling period has
11.1.6 Deactivate the photomultiplier tube.
ended.
11.1.7 Determine the calibration source count. Using
Count Designation, M Time Interval, T
(ab)
forceps, place the calibration point source on top and in the
M 2to5min(3min)
(2–5)
M 6to20min(14min)
center of the same phosphor disc as used in 11.1.3. (6–20)
M 21 to 30 min (9 min)
(21–30)
11.1.8 Coverandthenac
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