ASTM D6327-10(2021)

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: D6327 − 10 (Reapproved 2021)
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
concentrations and of the working level (WL) value corre-
responsibility of the user of this standard to establish appro-
sponding to those concentrations.
priate safety, health, and environmental practices and deter-
1.2 Measurementsmadeinaccordancewiththistestmethod
mine the applicability of regulatory limitations prior to use.
will produce RDP concentrations representative of closed-
See Section 9 for additional precautions
building conditions. Results of measurements made under
1.8 This international standard was developed in accor-
closed-building conditions will have a smaller variability and
dance with internationally recognized principles on standard-
are more reproducible than measurements obtained when ization established in the Decision on Principles for the
buildingconditionsarenotcontrolled.Thistestmethodmaybe
Development of International Standards, Guides and Recom-
utilized under non-controlled conditions, but a greater degree mendations issued by the World Trade Organization Technical
of variability in the results will occur. Variability in the results Barriers to Trade (TBT) Committee.
may also be an indication of temporal variability present at the
2. Referenced Documents
sampling site.
2.1 ASTM Standards:
1.3 Thistestmethodutilizesashortsamplingperiodandthe
D1356Terminology Relating to Sampling and Analysis of
results are indicative of the conditions only at the place and
Atmospheres
time of sampling. The results obtained by this test method are
D1605Practices for Sampling Atmospheres for Analysis of
not necessarily indicative of longer terms of sampling and
Gases and Vapors (Withdrawn 1992)
should not be confused with such results. The averaging of
D3631Test Methods for Measuring Surface Atmospheric
multiple measurements over hours and days can, however,
Pressure
provide useful screening information. Individual measure-
E1Specification for ASTM Liquid-in-Glass Thermometers
ments are generally obtained for diagnostic purposes.
3. Terminology
1.4 The range of the test method may be considered from
0.0005WLto unlimited working levels, and from 40 Bq/m to 3.1 Definitions—For definitions of terms used in this test
unlimited for each individual radon decay product. method, refer to Terminology D1356.
3.2 Definitions of Terms Specific to This Standard:
1.5 This test method provides information on equipment,
3.2.1 grab sampling, n—the act and all procedures involved
procedures, and quality control. It provides for measurements
with obtaining a short term sample through the use of an
within typical residential or building environments and may
operating air pump.
not necessarily apply to specialized circumstances, for
example, clean rooms.
3.2.2 radon, n—the particular isotope radon-222.
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 Sept. 1, 2021. Published September 2021. Originally the ASTM website.
approved in 1998. Last previous edition approved in 2016 as D6327–10 (2016). The last approved version of this historical standard is referenced on
DOI: 10.1520/D6327-10R21. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6327 − 10 (2021)
3.2.3 radon decay products (RDP), n—any or all of the 7. Apparatus
particular isotopes polonium-218, bismuth-214, lead-214, and
7.1 Collection Apparatus:
polonium-214.
7.1.1 Air pump capable of 10 to 12 L/min flow rate.
3.2.4 working level, n—quantity of short-lived decay prod-
7.1.2 Bubble tube airflow calibration cell, 1 L or larger.
uctsthatwillresultin1.3×10 MeVofpotentialalphaenergy
7.1.3 Calibrated dry gas meter.
per litre of air. The working level is the common unit for
7.1.4 Flow meter (optional).
expressing environmental RDP exposure.
7.1.5 Open-faced filter holder, 25 or 47-mm diameter.
7.1.6 Membrane filters, mixed cellulose ester, 25 or 47-mm
4. Summary of Test Method (1)
diameter, 0.8-µm pore size.
4.1 Grab sampling measurements of RDPconcentrations in
7.1.7 Sharpened forceps, for removal of sample filters.
airareperformedbycollectingtheRDPfromaknownvolume
7.1.8 Stopwatch, accurate to 1 s.
of air on a filter and subsequently counting the activity on the
7.2 Decay Counting Apparatus:
filter following collection. The counting is performed at
7.2.1 Zinc sulfide phosphor discs, 51-mm diameter.
specified times for specified periods. The energy from radio-
7.2.2 Scintillation Counter, scaler and photomultiplier tube.
active decay of the particles collected on the filter is converted
7.2.3 High voltage power supply.
to light pulses by a zinc sulfide phosphor in contact with the
filter. The light pulses are detected and converted to counts.
7.3 Thermometer (see Specification E1).
Analysis of the number of counts in each counting interval
7.4 Barometer (see Test Methods D3631).
determines the concentrations of the RDP. The two counting
methods which have found the most general use are the
8. Reagents and Materials
Kusnetz and the modified Tsivoglou procedures (2).
8.1 National Institute of Standards and Technology (NIST)
traceable alpha calibration source, typically americium-241, to
5. Significance and Use
determine counter efficiency (4, 5).
5.1 Thetestmethodprovidesarelativelysimplemethodfor
determinationoftheconcentrationofRDPwithouttheneedfor
9. Hazards
specialty equipment built expressly for such purposes.
9.1 Since radioactive material is being utilized, both in the
5.2 Using this test method will afford investigators of radon
form of calibration standards and particles collected on sample
indwellingsatechniquebywhichtheRDPcanbedetermined.
filters, wear disposable gloves during handling of these items.
The use of the results of this test method are generally for
diagnosticpurposesandarenotnecessarilyindicativeofresults 9.2 Iftheatmospheresbeingmeasuredareknowntocontain
that might be obtained by longer term measurement methods. high concentrations of RDP, wear an HEPA half-mask respi-
rator during sampling.
5.3 Animprovedunderstandingofthefrequencyofelevated
radon in buildings and the health effect of exposure has 9.3 The calibration source from NIST must be shielded
increased the importance of knowledge of actual exposures. when not being used for calibration. Shield the source by
The measurement of RDP, which are the direct cause of returningthesourcetotheoriginalNISTstoragecontainerand
potential adverse health effects, should be conducted in a placing the source in the original storage geometry within the
manner that is uniform and reproducible; it is to this end that container (4).
this test method is addressed.
10. Preparation of Apparatus
6. Interferences
10.1 Verify proper operation of the equipment prior to
6.1 Interferences may be caused by any alpha-emitting
collection of the sample. Refer to equipment manuals for
particle capable of inducing a light pulse in the phosphor
information.
screen used for alpha-counting. In general, the only significant
10.1.1 Operate each counting system at the high-voltage
interference source is that of the decay products of radon-220,
(HV) and threshold settings that combines maximum stability,
thoron, which may be considerable in certain geographical
good counting efficiency, and low background counts. Each
regions. The direction of the interference is always positive.
manufacturer’s counting systems have different set-up require-
The extent to which thoron decay products interfere can be
ments and optimization procedures. A general similar proce-
estimated or measured through alpha-spectroscopy or serial
dure is available (6).
type measurements (3).
10.2 Determine the counter efficiency and background for
6.2 Some depth penetration to the filter may occur. The
the sampling filter and phosphor screen pair prior to collection
extent of the penetration may be estimated using membrane
of the sample (see Section 11).
filtertypesnotsuggestedwithinthistestmethod.Thedirection
10.3 The air pump, filter assembly, and connecting tubing
of interferences is always negative.
shall not leak.
10.4 A volume meter is needed for measuring total sample
flow. A calibrated dry gas test meter is the most satisfactory
The boldface numbers in parentheses refer to a list of references at the end of
this standard. totalvolumemeteravailableforsourcetestwork.Calibratethe
D6327 − 10 (2021)
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. shows enhanced activity from previous sampling measure-
M
ments. Use the same phosphor disc for a filter before and after
10.5 Locate the scintillation counter to provide rapid access
collection of a sample with the filter. If the total count for 10
from the sampling site when the modified Tsivoglou counting
min is greater than 10, replace the filter and phosphor disc pair
procedureisutilized.Thisprocessisnecessaryduetotheshort
and recount. The number is the background count, B, and is
time period between sampling and the start of counting.
recorded in counts.
11.2.4 Remove the filter from the phosphor disc with the
11. Procedure
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.
11.2.6 Obtain the initial dry gas meter reading.
11.1.2 Deactivate the photomultiplier tube. Exposure of an
11.2.7 Draw sample air through the filter for 5.00 min.
activated photomultiplier tube to light while connected to
11.2.8 Obtain the final dry gas meter reading and record the
power may permanently damage the photomultiplier tube.
volume of air sampled in litres, V.
NOTE 1—Although comments have been received indicating any light
11.2.9 Disassemble the filter holder, and carefully transfer
incident on the deactivated photomultiplier tube, even though completely
the filter from the filter holder onto the phosphor disc with
disconnectedfrompower,willresultinspuriousaddition/deletionsoflight
which the background was just previously measured (exposed
pulses. Tests conducted with four photomultiplier tubes of two designs at
sample filter side oriented toward the phosphor disc). During
the Grand Junction DOE Facility Radon Chamber indicated no variation
thetransfer,inspectthefilterfortears.Ifatearisfound,discard
in background counts from photomultiplier tubes kept in the dark versus
the same tubes with large mercury arc lamps over the tubes.
and begin again. Cover the filter with the cover plate. Cover
and reactivate the photomultiplier tube.
11.1.3 Place a fresh phosphor disc (phosphor side up) at the
center of the photomultiplier lens.
11.3 Sample Counting—Two different counting techniques
11.1.4 Cover and activate the photomultiplier tube. The
are described in this section, a modified Tsivoglou Technique
photomultiplier shall not be opened to light while activated or
(see 11.3.1) and a Kusnetz Technique (see 11.3.2). Each
the electronics will be shocked. It is very important that there
technique requires a unique set of counting intervals.
be no power to the opened photomultiplier.
Additionally, each technique requires a separate set of calcu-
11.1.5 Activate the scintillation counter for a defined count-
lations as listed in Section 12.
ing interval in minutes, C. The counting interval shall be long
I 11.3.1 Modified Tsivoglou Technique—Operatethescintilla-
enoughtoobtainatleast10000countsfromthealpha-emitting
tion counter for the following time intervals. The intervals are
source. The number of counts obtained from the phosphor is
measured from the time the 5.00 min sampling period has
the background count, B .
cal
ended.
11.1.6 Deactivate the photomultiplier tube.
Count Designation, M Time Interval, T
(ab)
11.1.7 Determine the calibration source count. Using
M 2to5min(3min)
(2–5)
M 6to20min(14min)
forceps, place the calibration point source on top and in the
(6–20)
M 21 to 30 min (9 min)
(21–30)
center of the same phosphor disc as used in 11.1.3.
Record the total number of counts during each time interval
11.1.8 Coverandthenactivatethephotomultipliertube.The
M ,[M ,M , and M ].
photomultiplier shall not be opened to light while activated or ab (2–5) (6–20) (21–30)
the electronics will be shocked. It is very important that there
NOTE 2—Other counting techniques have been devised and are pres-
be no power to the opened photomultiplier.
ently in use. However, the most generally used counting technique is the
one presented here.
11.1.9 Activate the scintillation counter for the counting
interval, C, and the number counts obtained is the measured
I
11.3.2 Modified Kusnetz Technique—Operate the scintilla-
calibration count, M .
cal tion counter over any 10 min interval between 40 and 90 min
11.1.10 Calculate the efficiency of the counter using the
after the start of sampling. Record the total counts for the 10
equation in 12.2.
min interval, K, and the time (in minutes after the end of
sampling), t,atthe center of the 1
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