ASTM D1993-22 PDF

Full title and description

ASTM D1993-22 — Standard Test Method for Precipitated Silica‑Surface Area by Multipoint BET Nitrogen Adsorption. This method defines the procedure, sample handling and instrument requirements for determining the nitrogen BET surface area of precipitated (hydrated) silica using multipoint adsorption measurements.

Abstract

ASTM D1993-22 specifies a multipoint BET nitrogen adsorption procedure to determine the specific surface area of precipitated silica. It covers sample preparation and pretreatment, instrument calibration, data collection at multiple relative pressures, calculation of surface area using BET theory, and minimum accuracy/precision expectations for results in the typical range for precipitated silica.

General information

• Status: Active
• Publication date: October 1, 2022
• Publisher: ASTM International
• ICS / categories: 71.060.20 (Oxides)
• Edition / version: D1993‑22 (revision of D1993‑18)
• Number of pages: 3

Scope

This test method covers the multipoint BET nitrogen adsorption procedure used to measure the surface area of precipitated hydrated silicas. It is applicable to precipitated silicas with specific surface areas typically in the range of approximately 10 to 500 m2/g. The standard specifies sample conditioning and pretreatment, instrument calibration, acceptable data quality and precision, and the calculation procedure based on BET theory. Safety considerations (personal protective equipment and precautions for handling equipment/chemicals) are noted by the standard.

Key topics and requirements

• Multipoint BET adsorption measurements using nitrogen at liquid‑nitrogen temperature.
• Sample preparation and removal of adsorbed contaminants prior to measurement (degassing/conditioning).
• Instrument calibration and verification requirements to ensure measurement accuracy.
• Data collection at multiple relative pressures and selection of the BET linear range.
• Calculation of specific surface area (m2/g) using BET theory and required reporting conventions.
• Defined accuracy/precision limits and recommended quality checks for results.
• Notes on safety and laboratory practices (personal protective equipment; handling of apparatus and potential spills).

Typical use and users

Used by analytical and quality laboratories in the chemical, rubber, tire and filler industries, as well as by R&D groups and producers of precipitated silica. Typical users include materials scientists, process engineers, QC analysts and contract testing laboratories who need reliable surface area measurements for product specification, process control, formulation and comparative studies.

Related standards

Closely related ASTM methods and references include ASTM D6556 (carbon black surface area procedures referenced for multipoint approaches), earlier versions of D1993 (e.g., D1993‑18), and other surface area standards such as ISO 9277 (determination of specific surface area by gas adsorption — BET method). Relevant ASTM committee guidance and other adsorption/porosimetry standards may also be consulted for instrument performance and reporting conventions.

Keywords

precipitated silica, BET, multipoint BET, nitrogen adsorption, specific surface area, surface area determination, degassing, instrument calibration, wetted-surface area, filler characterization

FAQ

Q: What is this standard?

A: ASTM D1993-22 is the ASTM test method that defines a multipoint BET nitrogen adsorption procedure to measure the surface area of precipitated (hydrated) silica.

Q: What does it cover?

A: It covers sample preparation and pretreatment, instrument calibration, multipoint adsorption data collection at liquid‑nitrogen temperature, BET calculations to report specific surface area (typically 10–500 m2/g for precipitated silica), and basic safety notes.

Q: Who typically uses it?

A: Materials and analytical laboratories in silica production, rubber/tire and filler formulation, R&D teams, and third‑party testing labs use it for quality control, specification testing and comparative surface area measurement.

Q: Is it current or superseded?

A: The active version is D1993‑22, published October 1, 2022. It is a revision of earlier versions (for example D1993‑18). Users should confirm whether any amendments or newer revisions have been issued after that date before relying on the text for regulatory or contractual requirements.

Q: Is it part of a series?

A: It is part of ASTM Committee D11 test methods dealing with carbon, silica and related surface‑area measurement practices and is commonly grouped with other adsorption/porosimetry surface area standards and related material characterization methods.

Q: What are the key keywords?

A: precipitated silica, BET, nitrogen adsorption, surface area, multipoint BET, specific surface area, degassing, instrument calibration.