ASTM D6539-13由美国材料与试验协会 US-ASTM 发布于 2013。
。
4.1 This test method applies to the one-dimensional laminar (viscous) flow of air in porous materials such as soil.
Note 1—This test method deals with porous materials with both gaseous (air) and liquid (pore water) mobile fluids: The liquid phase is much less compressible, has a higher viscosity, and is much more tightly bound to the solid phase by chemical forces. The assumption of single-phase flow may still be presumed to be valid since the test gradient ensuring the conditions of laminar flow may be low enough that flow of the liquid phase is negligible.4.2 The degree of saturation of the specimen shall be less than that which would produce significant internal transport of pore water or alter the continuity of air voids under the applied gradients. The maximum permissible degree of saturation must be evaluated by an experienced analyst. In no instance shall the specimen be so saturated that pore water appears at the exit of the permeameter cell during the test.
4.3 This test method is based on the assumption that the rate of mass flow through the specimen is constant with time.
Note 2—When a specimen contains volatile materials this assumption is violated. The mass of gas flowing out will be greater than that flowing in, the gradient cannot be determined and the test may become meaningless. Such specimens pose special problems and must be decontaminated before analysis in order to minimize health and safety concerns and to prevent contamination of the test apparatus.4.4 The permeability of porous materials may be strongly dependent on a variety of physical properties including the void ratio, the degree of saturation, and percent and direction of compaction. It is beyond the scope of this test method to elaborate upon these dependencies. Rather, this test method is intended to be a measurement technique for determining the permeability under a certain set of laboratory conditions. It is the responsibility of the test requestor to specify which soil parameters must be controlled to ensure a valid extension of the test results to field conditions.
4.5 Calculation of the permeability using Darcy’s law requires laminar flow conditions through the soil specimen. The conditions for laminar flow shall be evaluated by plotting the volumetric flow rate of air through the specimen against the pressure drop across the specimen. If the individual test points lie within 25 % of a straight line passing through the origin, then laminar flow conditions are present and Darcy's law may be used to calculate the permeability.
Note 3—The permeability calculated using this standard is valid only when the degree of saturation does not change over time. Long measurement times associated with the use of bubble meters and manometers may indirectly lead to variability when measuring flow versus pressure drop (see 8.2) due to evaporation. The recommended use of digital electronic flow and pressure sensors leads to considerably reduced measurement times because the user can quickly determine by inspection when a steady state......常用标准:AFNOR G 07-111法国标准协会 透气性测试ASTM D 737纺织织物透气率的标准试验方法ASTM D 3574软质多孔材料测试方法BS 5636英国标准 纺织品透气性的测定方法DIN 53887纺织物空气透气度的测定EDANA 140.1 欧洲用可弃和非织造布制造协会EN ISO 7231软质泡沫聚合材料.恒定压降下的空气流量评估方法EN ISO 9237纺织品.纤维织物透气性的测定...
2018年12月, 由中石化,中石油,中海油,海关等相关权威单位联合起草的GB36170原油产品规范正式实施。在GB36170中规定了原油的技术要求和试验方法。而交接温度下蒸气压试验方法规定为GB/T11059-2011原油蒸气压的测定(膨胀法)。GB/T11059-2011标准修改采用了ASTM D6377 原油蒸气压的测定 膨胀法(英文版)。...
透气性测试主要用于检测薄膜,而透气度测试主要检测多孔材料、无纺布等。 其次,透气性测试可以检测氧气、氮气、二氧化碳、空气等气体对材料的渗透性,而透气度测试主要检测空气对材料的渗透性。 第三,试验时间长短差异较大,透气性测试时间长,透气度测试时间要短的多,这主要是因为两种测试材料透气性的差别非常大。 ...
其次,透气性测试可以检测氧气、氮气、二氧化碳、空气等气体对材料的渗透性,而透气度测试主要检测空气对材料的渗透性。 第三,试验时间长短差异较大,透气性测试时间长,透气度测试时间要短的多,这主要是因为两种测试材料透气性的差别非常大。...
Copyright ©2007-2022 ANTPEDIA, All Rights Reserved
京ICP备07018254号 京公网安备1101085018 电信与信息服务业务经营许可证:京ICP证110310号