ASTM E128-99(2011)

Standard Test Method for Maximum Pore Diameter and Permeability of Rigid Porous Filters for Laboratory Use

ABSTRACT
This test method covers the determination of maximum pore diameter and permeability of rigid porous filters used in the laboratory for filtration or diffusion. They are applicable to filters made of sintered glass, ceramic, metal, or plastic. This test method establishes a uniform designation for maximum pore diameter and also provides a means of detecting and measuring changes which occur through continued use. Maximum pore diameter is determined by immersing the filter in a suitable test liquid and applying air pressure until the first bubble of air passes through the filter. The maximum pore diameter is calculated from the surface tension of the test liquid and the applied pressure. Permeability is determined by measuring the flow of air through the filter when subjected to a pressure differential.
SCOPE
1.1 This test method covers the determination of maximum pore diameter and permeability of rigid porous filters used in the laboratory for filtration or diffusion. They are applicable to filters made of sintered glass, ceramic, metal, or plastic. This test method establishes a uniform designation for maximum pore diameter and also provides a means of detecting and measuring changes which occur through continued use.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety problems, 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: Historical
• Publication Date: 30-Sep-2011
• ICS: 71.040.20 - Laboratory ware and related apparatus
• Technical Committee: E41 - Laboratory Apparatus
• Drafting Committee: E41.01 - Laboratory Ware and Supplies

Relations

• Replaces: ASTM E128-99(2005) - Standard Test Method for Maximum Pore Diameter and Permeability of Rigid Porous Filters for Laboratory Use
• Effective Date: 01-Oct-2011
• Replaced By: 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
• Referred By: ASTM D3608-19 - Standard Test Method for Nitrogen Oxides (Combined) Content in the Atmosphere by the Griess-Saltzman Reaction
• Effective Date: 01-Oct-2011
• Referred By: ASTM D892-18e1 - Standard Test Method for Foaming Characteristics of Lubricating Oils
• Effective Date: 01-Oct-2011
• Referred By: ASTM F316-03(2019) - Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test
• Effective Date: 01-Oct-2011
• Referred By: ASTM D721-17 - Standard Test Method for Oil Content of Petroleum Waxes
• Effective Date: 01-Oct-2011
• Referred By: ASTM F3510-21 - Standard Guide for Characterizing Fiber-Based Constructs for Tissue-Engineered Medical Products
• Effective Date: 01-Oct-2011
• Referred By: ASTM F2150-19 - Standard Guide for Characterization and Testing of Biomaterial Scaffolds Used in Regenerative Medicine and Tissue-Engineered Medical Products
• Effective Date: 01-Oct-2011
• Referred By: ASTM D6082-23 - Standard Test Method for High Temperature Foaming Characteristics of Lubricating Oils
• Effective Date: 01-Oct-2011
• Referred By: ASTM D1881-17 - Standard Test Method for Foaming Tendencies of Engine Coolants in Glassware
• Effective Date: 01-Oct-2011
• Referred By: ASTM D3235-16e1 - Standard Test Method for Solvent Extractables in Petroleum Waxes
• Effective Date: 01-Oct-2011
• Referred By: ASTM F2902-16e1 - Standard Guide for Assessment of Absorbable Polymeric Implants
• Effective Date: 01-Oct-2011
• Referred By: ASTM D6908-06(2017) - Standard Practice for Integrity Testing of Water Filtration Membrane Systems
• Effective Date: 01-Oct-2011
• Referred By: ASTM D7840-12(2017) - Standard Test Method for Foaming Tendencies of Non-Aqueous Engine Coolants in Glassware
• Effective Date: 01-Oct-2011
• Referred By: ASTM D1607-91(2018)e1 - Standard Test Method for Nitrogen Dioxide Content of the Atmosphere (Griess-Saltzman Reaction)
• Effective Date: 01-Oct-2011

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E128 − 99 (Reapproved 2011)
Standard Test Method for
Maximum Pore Diameter and Permeability of Rigid Porous
Filters for Laboratory Use
This standard is issued under the fixed designation E128; 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.
pore in the filter, and furthermore, that the pores are highly irregular in
1. Scope
shape. Because of this irregularity in shape and other phenomena
1.1 This test method covers the determination of maximum
characteristic of filtration, a filter may be expected to retain all particles
pore diameter and permeability of rigid porous filters used in larger than the maximum pore diameter as defined and determined by this
test method, and will generally retain particles which are much smaller
the laboratory for filtration or diffusion. They are applicable to
than the determined diameter.
filters made of sintered glass, ceramic, metal, or plastic. This
3.1.2 permeability—the flow of air, in millimetres per min-
test method establishes a uniform designation for maximum
ute per square centimetre of filter area per 1 cm of water
pore diameter and also provides a means of detecting and
pressure differential.
measuring changes which occur through continued use.
1.2 The values stated in SI units are to be regarded as
4. Summary of Test Method
standard. No other units of measurement are included in this
4.1 Maximum Pore Diameter, is determined by immersing
standard.
the filter in a suitable test liquid and applying air pressure until
1.3 This standard does not purport to address all of the
the first bubble of air passes through the filter. The maximum
safety problems, if any, associated with its use. It is the
pore diameter is calculated from the surface tension of the test
responsibility of the user of this standard to establish appro-
liquid and the applied pressure.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. 4.2 Permeability is determined by measuring the flow of air
through the filter when subjected to a pressure differential.
2. Referenced Documents
5. Apparatus
2.1 ASTM Standards:
D845 Specification for Five-Degree Xylene (Withdrawn
5.1 Because of the variety of shapes of apparatus in which
1980)
porous filters are incorporated, the apparatus for this test
method is not specified in detail.Apparatus that has been found
3. Terminology
satisfactory is illustrated in Fig. 1 and Fig. 2.
3.1 Definitions:
3.1.1 maximum pore diameter—thediameterinmicrometres 6. Procedure
of a capillary of circular cross section that is equivalent (with
6.1 Maximum Pore Diameter—Thoroughly wet the clean
respect to characteristics related to surface-tension effects) to
filter to be tested by soaking it in the prescribed test liquid (see
the largest pore in the filter under consideration.
Table 1). Connect the filter to a controllable source of clean,
dry compressed air, and a manometer (Fig. 1). Immerse the
NOTE 1—It is recognized that the maximum pore diameter as defined
herein does not necessarily indicate the physical dimensions of the largest filter just below the surface of the test liquid (Note 2) and
gradually increase the air pressure at a rate of about 5 mm/min
in the area of the test until the first dynamic bubble passes
This test method is under the jurisdiction of ASTM Committee E41 on
through the filter and rises through the liquid. The appearance
Laboratory Apparatus and is the direct responsibility of Subcommittee
of the first true dynamic bubble is readily recognized since it is
E41.01Apparatus Materials.
Current edition approved Oct. 1, 2011. Published November 2011. Originally followed by a succession of additional bubbles. Read the
approvedin1957.Lastpreviouseditionapprovedin2005asE128 – 99(2005).DOI:
pressure from the manometer. If the test is to be repeated,
10.1520/E0128-99R11.
thoroughly re-wet the filter by soaking it in the test liquid,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
before proceeding with the retest. Calculate the maximum pore
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on diameter from the following equation (see Appendix X1 for
the ASTM website.
derivation):
The last approved version of this historical standard is referenced on
www.astm.org. D 5 30γ/p (1)
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E128 − 99 (2011)
NOTE 1—For tests on filter-type crucibles, use a standard rubber crucible adapter. For test sticks and candles a rubber stopper with a rubber tubing
attached is suitable. Clean dry compressed air shall be used.
FIG. 1 Apparatus for Determining Maximum Pore Diameter of Rigid Porous Filters
NOTE 1—For tests on filter-type crucibles, use a standard rubber crucible adapter. For test sticks and candles a rubber stopper with a rubber tubing
attached is suitable. Clean dry compressed air shall be used.
FIG. 2 Apparatus for Determination of Permeability
TABLE 1 Test Liquids Suitable for Use with Various Types of Filters
A
Filter Suitable Test Liquids
Approximate Surface
Max Pore Diameter, Tension, dynes/cm at
Material of Construction µm Liquid 20°C
Glass >4 water 72
B
<4 alcohol 22
Porcelain >3 water 72
<3 alcohol 22
Stainless steel all alcohol 22
C
xylene 29
Tetrafluoro-polyethylene all alcohol 22
Trifluoromonochloropolyethylene all alcohol 22
A
The specified liquids wet the respective filters completely. Other liquids which meet this crite
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