ASTM E1294-89 (1999) PDF

Full title and description

ASTM E1294-89 (Reapproved 1999) — Standard Test Method for Pore Size Characteristics of Membrane Filters Using Automated Liquid Porosimeter. Describes an automated liquid-displacement (bubble point/mean flow) procedure and instrumentation for determining pore-size characteristics of membrane filters, including maximum pore size (bubble point), minimum detectable pore, mean flow pore, and pore-size distributions by flow, number, and volume.

Abstract

This test method specifies an automated liquid porosimetry procedure for measuring pore-size characteristics of membrane filters over a broad range (approximately 0.05 to 300 µm). The method uses wetting liquids compatible with the membrane, applies increasing air pressure upstream of a wetted sample, and records flow versus pressure to determine bubble point (maximum pore), mean flow pore, and distribution data derived from pressure–flow curves using the Washburn equation. The standard was reapproved in 1999 and subsequently withdrawn in 2008.

General information

• Status: Withdrawn (2008)
• Publication date: Original approval 1989; reapproved 1999 (effective Oct 10, 1999); withdrawn Sep 23, 2008
• Publisher: ASTM International
• ICS / categories: 71.040.20 (Laboratory ware and related apparatus)
• Edition / version: E1294-89 (Reapproved 1999)
• Number of pages: 2 (concise test-method booklet)

Scope

This standard describes a procedure for measuring pore-size characteristics of membrane filters in the range of approximately 0.05 to 300 µm using an automated liquid porosimeter. It specifies use of the automated bubble-point approach (as referenced to ASTM F316), selection of appropriate wetting liquids, instrumentation requirements (automated liquid porosimeter, compressed-air source, sample holders), and calculation approaches based on capillary theory (Washburn equation). The method focuses on laboratory determination of maximum pore (bubble point), mean flow pore, and pore-size distributions by flow, number, and volume.

Key topics and requirements

• Measurement range: approximately 0.05 to 300 µm.
• Automated liquid porosimetry using bubble-point/mean-flow pore techniques.
• Use of compatible low-surface-tension and low-vapor-pressure wetting liquids (examples: isopropyl alcohol, mineral oil, water) and reagent-grade materials.
• Instrumentation: automated liquid porosimeter, regulated compressed-air source (up to ~150 psi or as required), appropriate sample holders and cutters.
• Data handling: record flow versus applied pressure; identify bubble point (first detectable flow), derive mean flow pore and pore-size distributions from wet and dry curves using the Washburn equation.
• Safety and materials compatibility considerations for selected test liquids and membrane materials.
• Reference to related ASTM methods (notably ASTM F316) for bubble-point technique and test practices.

Typical use and users

Used by membrane and filter manufacturers, quality control and R&D laboratories, academic researchers working in filtration and membrane science, and purchasers or regulators assessing filter performance. Typical applications include manufacturing quality checks, comparative characterization of membrane lots, research on membrane structure and pore distribution, and verification of maximum pore and mean flow pore for process or product specifications.

Related standards

Closely related standards and guides include ASTM F316 (bubble point and mean flow pore tests for membrane filters), later ASTM test methods and guides addressing pore characterization and scaffold/porous-material measurement (for example standards referenced in filtration and biomaterials testing), and other ASTM porosimetry-related methods such as E128 (pore diameter and permeability of rigid porous filters). This standard was withdrawn without a direct one-to-one replacement; practitioners commonly refer to more recent ASTM pore-measurement methods and instrument manufacturer procedures for current practice.

Keywords

membrane filter; pore size; bubble point; mean flow pore; automated liquid porosimeter; porosimetry; Washburn equation; pore-size distribution; filtration testing; ASTM E1294.

FAQ

Q: What is this standard?

A: ASTM E1294-89 (Reapproved 1999) is a test method that defines an automated liquid-porosimeter procedure for determining pore-size characteristics of membrane filters (bubble point, mean flow pore, and distributions).

Q: What does it cover?

A: It covers test method requirements and procedures for wetting membrane samples, applying increasing air pressure, recording flow vs. pressure, identifying the bubble point (maximum pore), calculating mean flow pore, and deriving pore-size distributions from pressure–flow data using capillary theory (Washburn equation). The practical measurement range cited is roughly 0.05–300 µm.

Q: Who typically uses it?

A: Membrane and filter manufacturers, quality-control laboratories, research groups studying membranes and porous materials, instrument vendors, and specification writers for filtration products.

Q: Is it current or superseded?

A: The standard was withdrawn in 2008 and is not current. Users should consult more recent ASTM methods (for example methods addressing bubble-point and mean-flow-pore tests) and current instrument manufacturer procedures for up-to-date test practice.

Q: Is it part of a series?

A: It is part of ASTM’s family of porous-media and filtration test methods and was maintained under Committee E48. It references and is related to other ASTM test methods for pore measurement (notably ASTM F316 and other porosimetry-related standards), but it does not form a numbered “series” beyond related test-method collections within ASTM.

Q: What are the key keywords?

A: membrane filter, pore size, bubble point, mean flow pore, automated liquid porosimeter, porosimetry, Washburn equation, pore-size distribution.