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5.1 This test method is intended to provide information on the ability of an extruded catalyst to retain physical integrity during use.1.1 This test method covers and is suitable for determining the resistance of extruded catalysts and catalyst carriers to compressive force from the side.1.2 This test method was developed using extruded catalyst and catalyst carriers from 1/16 to 1/8 in. in diameter (0.159 to 0.318 cm) and limited to pieces with a length to diameter ratio greater than or equal to 1:1. This test method may be applicable to other diameters.1.3 This test method is suitable for the determination of mean crush strength per millimetre in the range of 0 to 15 lbf/mm (0 to 65 N/mm).1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.5 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.1.6 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.

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5.1 This test method is to be used for measuring the vibratory packing density of formed particles that will not break up during sampling, filling, or vibrating of the measuring cylinder under test conditions.1.1 This test method covers the determination of the vibratory packing density of formed catalyst and catalyst carriers. For the purpose of this test, catalyst particles are defined as extrudates, spheres, or formed pellets of 0.8-mm to 4.8-mm (1/32-in. to 3/16-in.) nominal diameter.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 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.1.4 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.

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4.1 Compaction tests on soils performed in accordance with Test Methods D698, D1557, D4253, and D7382 place limitations on the maximum size of particles that may be used in the test. If a soil contains cobbles or gravel, or both, test options may be selected which result in particles retained on a specific sieve being discarded (for example the 4.75-mm [No. 4], the 19-mm [3/4-in.] or other appropriate size) and the test performed on the finer fraction. The unit weight-water content relations determined by the tests reflect the characteristics of the actual material tested, and not the characteristics of the total soil material from which the test specimen was obtained.4.2 It is common engineering practice to use laboratory compaction tests for the design, specification, and construction control of soils used in earth construction. If a soil used in construction contains large particles, and only the finer fraction is used for laboratory tests, some method of correcting the laboratory test results to reflect the characteristics of the total soil is needed. This practice provides a mathematical equation for correcting the unit weight and water content of the finer fraction of a soil, tested to determine the unit weight and water content of the total soil.4.3 Similarly, as utilized in Test Methods D1556/D1556M, D2167, D6938, D7698, and D7830/D7830M, this practice provides a means for correcting the unit weight and water content of field compacted samples of the total soil, so that values can be compared with those for a laboratory compacted finer fraction.NOTE 2: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.NOTE 3: When this practice is used for construction control, the using agency should specify whether the maximum unit weight value used for reference is the unit weight including oversize fraction or the unit weight of the finer fraction. Calculated values of percent compaction based on this correction practice will vary depending on which unit weight value is used for reference.1.1 This practice presents a procedure for calculating the unit weights and water contents of soils containing oversize particles when the data are known for the soil fraction with the oversize particles removed.1.2 This practice also can be used to calculate the unit weights and water contents of soil fractions when the data are known for the total soil sample containing oversize particles.1.3 This practice is based on tests performed on soils and soil-rock mixtures in which the portion considered oversize is that fraction of the material retained on the 4.75-mm [No. 4] sieve. Based on these tests, this practice is applicable to soils and soil-rock mixtures in which up to 40 % of the material is retained on the 4.75-mm [No. 4] sieve. The practice also is considered valid when the oversize fraction is that portion retained on some other sieve, but the limiting percentage of oversize particles for which the correction is valid may be lower. However, the practice is considered valid for materials having up to 30 % oversize particles when the oversize fraction is that portion retained on the 19-mm [3/4-in.] sieve.1.4 The factor controlling the maximum permissible percentage of oversize particles is whether interference between the oversize particles affects the unit weight of the finer fraction. For some gradations, this interference may begin to occur at lower percentages of oversize particles, so the limiting percentage must be lower for these materials to avoid inaccuracies in the computed correction. The person or agency using this practice shall determine whether a lower percentage is to be used.1.5 This practice may be applied to soils with any percentage of oversize particles subject to the limitations given in 1.3 and 1.4. However, the correction may not be of practical significance for soils with only small percentages of oversize particles. The person or agency specifying this practice shall specify a minimum percentage of oversize particles below which the practice need not be applied. If a minimum percentage is not specified, 5 % shall be used.1.6 This practice may not be applicable to soil-rock mixtures which degrade under field compaction.1.7 Units—The values stated in either SI Units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.7.1 It is common practice in the engineering profession to concurrently use pounds to represent both a unit of mass (lbm) and a force (lbf). This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. This standard has been written using the gravitational system of units when dealing with the inch-pound system. In this system, the pound (lbf) represents a unit of force (weight). However, the use of balances or scales recording pounds of mass (lbm) or the recording of density in lbm/ft3 shall not be regarded as a non conformance with this standard.NOTE 1: Sieve size is identified by its standard designation in Specification E11. The alternative designation given in brackets is for information only and does not represent a different standard sieve size.1.8 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.8.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining data, special purpose studies, or any considerations for the user‘s objectives; and it is common practice to increase or reduce significant digits of reported data to commensurate with these considerations. It is beyond the scope of these test methods to consider significant digits used in analysis methods for engineering design.1.9 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.1.10 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.

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5.1 This test method is used for measuring the vibratory packing density of formed particles used in fixed bed reactors, driers, and so forth.1.1 This test method covers the determination of the vibratory packing density of formed catalyst and catalyst carrier particles that will not break up significantly under test conditions. For the purpose of this test, catalyst particles are defined as extrudates, spheres or formed pellets greater than 4.8 mm.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 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.1.4 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.

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5.1 Reported particle size measurement is a function of both the actual particle dimension and shape factor, as well as the particular physical or chemical properties of the particle being measured. Caution is required when comparing data from instruments operating on different physical or chemical parameters or with different particle size measurement ranges. Sample acquisition, handling, and preparation can also affect the reported particle size results.1.1 These test methods cover the determination of the size distribution and quantity of particulate matter contamination from aerospace fluids isolated on a membrane filter. The microscopical techniques described may also be applied to other properly prepared samples of small particles. Two test methods are described for sizing particles as follows:1.1.1 Test Method A—Particle sizes are measured as the diameter of a circle whose area is equal to the projected area of the particle.1.1.2 Test Method B—Particle sizes are measured by their longest dimension.1.2 The test methods are intended for application to particle contamination determination of aerospace fluids, gases, surfaces, and environments.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 These test methods do not provide for sizing particles smaller than 5 μm.NOTE 1: Results of these methods are subject to variables inherent in any statistical method. The use of these methods as a standard for initially establishing limits should be avoided unless ample tolerances are permissible.1.5 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.1.6 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.

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5.1 Low temperature fuel cells such as proton exchange membrane fuel cells (PEMFCs) require high purity hydrogen for maximum material performance and lifetime. The particulates in hydrogen used in FCVs and hydrogen powered internal combustion vehicles may adversely affect pneumatic control components, such as valves or other critical system components. The visualization of the size and morphology of particles is an important tool for determining particle origin as well as for devising particle formation reduction strategies.1.1 This test method is primarily intended for visualizing and measuring the sizes and morphology of particulates in hydrogen used as a fuel for fuel cell or internal combustion engine powered vehicles. This test method describes procedures required to obtain size and morphology data of known quality. This test method can be applied to other gaseous samples requiring determination of particulate sizes and morphology provided the user’s data quality objectives are satisfied.1.2 Mention of trade names in standard does not constitute endorsement or recommendation. Other manufacturers of equipment, software or equipment models can be used.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 and health practices and determine the applicability of regulatory limitations prior to use.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.

定价： 590元 加购物车

定价： 571元 加购物车

定价： 571元 加购物车

定价： 646元 加购物车