EN ISO 18757:2005 PDF
Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of specific surface area of ceramic powders by gas adsorption using the BET method (ISO 18757:2003)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of specific surface area of ceramic powders by gas adsorption using the BET method (ISO 18757:2003)
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 16
- Дата публикации:
- 19 октября 2005 г.
- Издание:
- CEN EN 18757 edition 2 version 1
- ICS:
- 81.060.30
ISO 18757:2003 provides guidelines for the determination of the total specific external and internal surface area of disperse or porous (pore diameter greater than 2 nm) fine ceramic materials by measuring the amount of physically adsorbed gas according to the method of Brunauer, Emmett and Teller (BET method). This International Standard only focuses on specific details relevant to fine ceramic materials. It should further be noted that the BET method cannot be applied to type I isotherms (microporous materials or chemisorption behaviour) or when the solid adsorbs the measuring gas.
Abstract
Overview
EN ISO 18757:2005 (ISO 18757:2003) specifies a standardized procedure for determining the specific surface area of fine ceramic powders (advanced/technical ceramics) by gas adsorption using the BET method (Brunauer–Emmett–Teller). The standard provides guidance for measuring the total external and accessible internal surface area of disperse or porous ceramic materials with pore diameters > 2 nm by recording adsorption isotherms and calculating the monolayer capacity. It clarifies details specific to fine ceramics and states important limitations (e.g., not applicable to type I isotherms, microporous materials, chemisorption behavior or when the solid chemically absorbs the measuring gas).
Key topics
- Measurement principle: Determination of monolayer capacity from adsorption isotherms using the BET approach; results relate to specific surface area per unit mass.
- Adsorbates: Commonly nitrogen at 77 K; argon or krypton at liquid-nitrogen temperature recommended for low surface-area samples.
- Sample preparation / outgassing: Critical step. Typical outgassing temperatures for many ceramics are 150–300 °C, with evacuation to pressures of **
Технические детали
- Технический комитет
- CEN/TC 184 - Advanced technical ceramics
- SKU
- EN ISO 18757:2005
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