ASTM F316-03(2019)

Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test

SIGNIFICANCE AND USE
5.1 This test method may be used to:  
5.1.1 Determine the maximum pore size of a filter,  
5.1.2 Compare the maximum pore sizes of several filters, and  
5.1.3 Determine the effect of various processes such as filtration, coating, or autoclaving on the maximum pore size of a membrane.  
5.2 Membrane filters have discrete pores from one side to the other of the membrane, similar to capillary, tubes. The bubble point test is based on the principle that a wetting liquid is held in these capillary pores by capillary attraction and surface tension, and the minimum pressure required to force liquid from these pores is a function of pore diameter. The pressure at which a steady stream of bubbles appears in this test is the bubble point pressure. The bubble point test is significant not only for indicating maximum pore size, but may also indicate a damaged membrane, ineffective seals, or a system leak.  
5.3 The results of this test method should not be used as the sole factor to describe the limiting size for retention of particulate contaminants from fluids. The effective pore size calculated from this test method is based on the premise of capillary pores having circular cross sections, and does not refer to actual particle size retention. See Test Method E128 for additional information.
SCOPE
1.1 These test methods cover the determination of two of the pore size properties of membrane filters with maximum pore sizes from 0.1 to 15.0 μm.  
1.2 Test Method A presents a test method for measuring the maximum limiting pore diameter of nonfibrous membranes. The limiting diameter is the diameter of a circle having the same area as the smallest section of a given pore (Fig. 1).
FIG. 1 Examples of Limiting Diameters  
1.3 Test Method B measures the relative abundance of a specified pore size in a membrane, defined in terms of the limiting diameter.  
1.4 The analyst should be aware that adequate collaborative data for bias statements as required by Practice D2777 is not provided. See the precision and bias section for details.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2019
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D19 - Water
• Drafting Committee: D19.08 - Membranes and Ion Exchange Materials

Relations

• Replaces: ASTM F316-03(2011) - Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test
• Effective Date: 01-Nov-2019
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM E128-99(2019) - Standard Test Method for Maximum Pore Diameter and Permeability of Rigid Porous Filters for Laboratory Use
• Effective Date: 01-Nov-2019
• Refers: ASTM D2777-12 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jun-2012
• Refers: ASTM E128-99(2011) - Standard Test Method for Maximum Pore Diameter and Permeability of Rigid Porous Filters for Laboratory Use
• Effective Date: 01-Oct-2011
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM D2777-08 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jan-2008
• Refers: ASTM D1129-06ae1 - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D1129-06a - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D2777-06 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Aug-2006
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1129-06 - Standard Terminology Relating to Water
• Effective Date: 15-Feb-2006
• Refers: ASTM E128-99(2005) - Standard Test Method for Maximum Pore Diameter and Permeability of Rigid Porous Filters for Laboratory Use
• Effective Date: 01-May-2005
• Refers: ASTM D1129-04 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2004
• Refers: ASTM D1129-04e1 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2004

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: F316 − 03 (Reapproved 2019)
Standard Test Methods for
Pore Size Characteristics of Membrane Filters by Bubble
Point and Mean Flow Pore Test
ThisstandardisissuedunderthefixeddesignationF316;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D1193 Specification for Reagent Water
D2777 Practice for Determination of Precision and Bias of
1.1 These test methods cover the determination of two of
Applicable Test Methods of Committee D19 on Water
the pore size properties of membrane filters with maximum
E128 Test Method for Maximum Pore Diameter and Perme-
pore sizes from 0.1 to 15.0 µm.
ability of Rigid Porous Filters for Laboratory Use
1.2 Test MethodApresents a test method for measuring the
maximum limiting pore diameter of nonfibrous membranes.
3. Terminology
The limiting diameter is the diameter of a circle having the
3.1 Definitions:
same area as the smallest section of a given pore (Fig. 1).
3.1.1 For definitions of terms used in this standard, refer to
1.3 Test Method B measures the relative abundance of a
Terminology D1129.
specified pore size in a membrane, defined in terms of the
3.2 Definitions of Terms Specific to This Standard:
limiting diameter.
3.2.1 limiting pore diameter, n—diameter of a circle having
1.4 The analyst should be aware that adequate collaborative
the same area as the smallest section of a given pore.
data for bias statements as required by Practice D2777 is not
3.2.2 pore size, n—capillary equivalent pore diameter.
provided. See the precision and bias section for details.
1.5 The values stated in SI units are to be regarded as
TEST METHOD A—MAXIMUM PORE SIZE
standard. No other units of measurement are included in this
standard.
4. Summary of Test Method
1.6 This standard does not purport to address all of the
4.1 The bubble point test for maximum pore size is per-
safety concerns, if any, associated with its use. It is the
formed by prewetting the filter, increasing the pressure of gas
responsibility of the user of this standard to establish appro-
upstream of the filter at a predetermined rate and watching for
priate safety, health, and environmental practices and deter-
gas bubbles downstream to indicate the passage of gas through
mine the applicability of regulatory limitations prior to use.
the maximum diameter filter pores.
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4.2 The pressure required to blow the first continuous
ization established in the Decision on Principles for the
bubbles detectable by their rise through a layer of liquid
Development of International Standards, Guides and Recom-
covering the filter is called the “bubble point,” and is used to
mendations issued by the World Trade Organization Technical
calculate maximum pore size.
Barriers to Trade (TBT) Committee.
5. Significance and Use
2. Referenced Documents
2 5.1 This test method may be used to:
2.1 ASTM Standards:
5.1.1 Determine the maximum pore size of a filter,
D1129 Terminology Relating to Water
5.1.2 Compare the maximum pore sizes of several filters,
and
These test methods are under the jurisdiction of ASTM Committee D19 on
5.1.3 Determine the effect of various processes such as
Water and are the direct responsibility of Subcommittee D19.08 on Membranes and
Ion Exchange Materials.
filtration, coating, or autoclaving on the maximum pore size of
Current edition approved Nov. 1, 2019. Published December 2019. Originally
a membrane.
approved in 1970. Last previous edition approved in 2011 as F316 – 03 (2011).
DOI: 10.1520/F0316-03R19.
5.2 Membrane filters have discrete pores from one side to
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
the other of the membrane, similar to capillary, tubes. The
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
bubble point test is based on the principle that a wetting liquid
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. is held in these capillary pores by capillary attraction and
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
F316 − 03 (2019)
6.3 Pressure Gauges (and mercury manometer if required),
covering the range of pressures needed for the pore sizes under
investigation (see Table 1).
6.4 Metal Punch, used to cut a suitable size filter from the
test sheet to fit the test filter holder.
7. Reagents
7.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
FIG. 1 Examples of Limiting Diameters all reagents shall conform to the specifications of the Commit-
tee on Analytical Reagents of the American Chemical Society
where such specifications are available. Other grades may be
surface tension, and the minimum pressure required to force
used provided it is first ascertained that the reagent is of
liquid from these pores is a function of pore diameter. The
sufficient high purity to permit its use without lessening the
pressureatwhichasteadystreamofbubblesappearsinthistest
accuracy of the determination.
is the bubble point pressure.The bubble point test is significant
not only for indicating maximum pore size, but may also
7.2 Water, conforming to Specification D1193, Type IV or
indicate a damaged membrane, ineffective seals, or a system
higher purity.
leak.
7.3 Denatured Alcohol.
5.3 The results of this test method should not be used as the
7.4 Petroleum Distillate, with surface tension of 30
sole factor to describe the limiting size for retention of
dynes/cm at 25°C.
particulate contaminants from fluids. The effective pore size
7.5 Mineral Oil, such as USP liquid petrolatum heavy, with
calculated from this test method is based on the premise of
surface tension of 34.7 dynes/cm at 25°C.
capillary pores having circular cross sections, and does not
refertoactualparticlesizeretention.SeeTestMethodE128for
7.6 1,1.2-trichloro-l,2,2-trifluoroethane (Freon TF), avail-
additional information.
able from commercial chemical supply houses.
7.7 Clean Gas Pressure Source, with regulation (filtered air
6. Apparatus
or nitrogen).
6.1 Filter Holder, as shown in Fig. 2, consisting of a baseA,
NOTE 2—Table 1 lists the nominal surface tension of these liquids at
a locking ring B, O-ring seal C, support disk D, and gas inlet
25°C. Table 2 lists the simplified maximum pore size formulas based on
E. The support disk shall be 2-ply construction, consisting of a
these values, where the liquid completely wets the membrane.
100 by 100 mesh or finer screen and a perforated metal plate
8. Procedure
for rigidity. The diameter of the test filter may be either 25 or
47 mm, as appropriate to the holder being used for the test. 8.1 Wet the test membrane completely by floating it on a
pool of the liquid. Use a vacuum chamber to assist in wetting
6.2 Manifold,asshowninFig.3,amicrometricflowcontrol
the filter, if needed.
valve capable of providing a linear rise in pressure and a gas
ballast of at least 16 000-cm capacity.
8.2 Place the wet membrane in the filter holder.
NOTE 1—For less accurate determinations, the simplified apparatus
8.3 Close the filter holder and apply slight gas pressure to
shown in Fig. 4 may be used.
eliminate possible liquid back flow.
8.4 Cover the perforated metal plate with 2 to 3 mm of test
liquid.
8.5 Increase the gas pressure slowly. Record the lowest
pressure at which a steady stream of bubbles rises from the
central area of the liquid reservoir.
NOTE 3—Faulty sealing may cause erroneous bubbling from the sealing
edge of the liquid reservoir. Be sure to record the bubble point pressure
with bubbles from the central area of the reservoir (see Fig. 5).
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Standard-Grade Reference Materials, American Chemical Society, Washington,
DC. For suggestions on the testing of reagents not listed by theAmerican Chemical
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
FIG. 2 Filter Holder copeial Convention, Inc. (USPC), Rockville, MD.
F316 − 03 (2019)
Key Quantity Component
1 1 Filter
2 1 Pressure regulator
3 1 Pressure gauge
4 1 Valve shutoff, manual
5 1 Valve, flow control, manual
6 4 Valve, solenoid, nc
7 1 Air ballast
8 1 Quick disconnect fitting
9 2 Open filter holder, 47 mm
10 1 Valve, 3-way, manual
11 1 Test gauge, 0-0.3 kPa (0-30 psig)
12 1 Test gauge, 0-0.8 kPa (0-100 psig)
13 1 Exhaust silencer
14 2 Pilot light, red, elec.
15 1 Switch, spdt, elec.
FIG. 3 Manifold for Bubble Point Testing
where:
d = limiting diameter, µm,
γ = surface tension, mN/m, (dynes/cm),
p = pressure, Pa or cm Hg, and
C = constant,2860when pisinPa,2.15when pisincmHg,
and 0.415 when p is in psi units.
NOTE 4—The fluid must completely wet the membrane filter with the
contact angle being zero. If the contact angle is greater than zero, the
calculated effective pore size will be larger than the actual effective pore
size rating.
10. Reporting Results
10.1 Record the minimum pressure for gas passage as
indicated by continuous bubbles. Record the maximum pore
size calculated, along with identification of the membrane
FIG. 4 Test Setup (Simplified)
tested and the liquid used.
TEST METHOD B—DETERMINATION OF PORE
9. Calculation
SIZE DISTRIBUTION
9.1 If the test liquid is known to wet the membrane
completely, calculate the maximum pore size from the follow- 11. Summ
...