1.1 本试验方法涵盖了通过常规Brunauer、Emmett和Teller（BET）测量沉淀水合二氧化硅表面积的程序 2. 使用多点测定的多层气体吸附行为理论，类似于试验方法中用于炭黑的理论 第6556页 本试验方法规定了样品制备和处理、仪器校准、实验数据所需的精度和精密度，以及根据获得的数据计算表面积结果。 1.2 本试验方法用于测定比表面积在10至500 m范围内的沉淀二氧化硅的氮表面积 2. /g。 1.3 以国际单位表示的值应视为标准值。本标准不包括其他计量单位。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 最低安全设备应包括防护手套、坚固的眼睛和面部保护以及安全处理意外汞泄漏的方法。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 3.1 该测试方法用于使用多点（B.E.T.）方法测量氮分子可用的沉淀、水合二氧化硅的表面积。根据试验方法测量单点氮表面积 D5604 . 3.2 固体吸附氮，在特定条件下，吸附的分子接近单分子层。使用BET方程计算该假设单分子层中的量。 将其与氮分子占据的面积相结合，得到固体的总表面积。 3.3 该测试方法通过在液氮温度和几个（至少五个）氮分压下的吸附来测量单分子层中氮的估计量。 3.4 在进行表面积测定之前，有必要将二氧化硅剥离掉可能已经吸附在表面上的任何材料。吸附异物的剥离消除了两个潜在的错误。第一个误差与异物的重量有关。第二个误差与异物占据的表面积有关。

1.1 This test method covers a procedure which is used to measure the surface area of precipitated hydrated silicas by the conventional Brunauer, Emmett, and Teller (BET) 2 theory of multilayer gas adsorption behavior using multipoint determinations, similar to that used for carbon black in Test Method D6556 . This test method specifies the sample preparation and treatment, instrument calibrations, required accuracy and precision of experimental data, and calculations of the surface area results from the obtained data. 1.2 This test method is used to determine the nitrogen surface area of precipitated silicas with specific surface areas in the range of 10 to 500 m 2 /g. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 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. The minimum safety equipment should include protective gloves, sturdy eye and face protection, and means to deal safely with accidental mercury spills. 1.5 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. ====== Significance And Use ====== 3.1 This test method is used to measure the surface area of precipitated, hydrated silicas that is available to the nitrogen molecule using the multipoint (B. E. T.) method. Single point nitrogen surface area is measured in accordance with the Test Methods D5604 . 3.2 Solids adsorb nitrogen, and under specific conditions, the adsorbed molecules approach a monomolecular layer. The quantity in this hypothetical monomolecular layer is calculated using the BET equation. Combining this with the area occupied by the nitrogen molecule yields the total surface area of the solid. 3.3 This test method measures the estimated quantity of nitrogen in the monomolecular layer by adsorption at liquid nitrogen temperature and at several (at least five) partial pressures of nitrogen. 3.4 Before a surface area determination can be made it is necessary that the silica be stripped of any material which may already be adsorbed on the surface. The stripping of adsorbed foreign material eliminates two potential errors. The first error is associated with the weight of the foreign material. The second error is associated with the surface area that the foreign material occupies.