定价： 2331元 / 折扣价： 2075 元 加购物车

定价： 1665元 / 折扣价： 1482 元 加购物车

定价： 2663元 / 折扣价： 2371 元 加购物车

4.1 The purpose of this guide is to provide guidance for selecting appropriate device size(s) and determining appropriate sample size(s) for design verification of endovascular devices. The device size(s) and sample size(s) for each design input requirement should be determined before testing. The device size(s) selected for verification testing should establish that the entire device matrix is able to achieve the design input requirements. If testing is not performed on all device sizes, justification should be provided.4.2 The sample size justification and statistical procedures used to analyze the data should be based on sound scientific principles and should be suitable for reaching a justifiable conclusion. Insufficient sample size may lead to erroneous conclusions more often than desired.4.3 Guidance regarding methodologies for determining device size selection and appropriate sample size is provided in Sections 5 and 6.1.1 This guide provides guidance for selecting an appropriate device size(s) and determining an appropriate sample size(s) (that is, number of samples) for design verification testing of endovascular devices. A methodology is presented to determine which device size(s) should be selected for testing to verify the device design adequately for each design input requirement (that is, test characteristic). Additionally, different statistical approaches are presented and discussed to help guide the developer to determine and justify sample size(s) for the design input requirement being verified. Alternate methodologies for determining device size selection and sample size selection may be acceptable for design verification.1.2 This guide applies to physical design verification testing. This guide addresses in-vitro testing; in-vivo/animal studies are outside the scope of this guide. This guide does not directly address design validation; however, the methodologies presented may be applicable to in-vitro design validation testing. Guidance for sampling related to computational simulation (for example, sensitivity analysis and tolerance analysis) is not provided. Guidance for using models, such as design of experiments (DOE), for design verification testing is not provided. This guide does not address sampling across multiple manufacturing lots as this is typically done as process validation. Special considerations are to be given to certain tests such as fatigue (see Practice E739) and shelf-life testing (see Section 8).1.3 Regulatory guidance may exist for endovascular devices that should be considered for design verification device size and sample size selection.1.4 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this 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.

定价： 646元 加购物车

定价： 646元 加购物车

This specification covers round, metallic coated, hard-drawn, carbon steel spring wire having properties and quality for the manufacture of mechanical springs and wire forms that are not subject to high stress or require high fatigue properties. The steel specimens shall be either ingot cast or strand cast and shall be cold drawn. Prior to cold drawing, the specimens shall be furnished into three types of metallic coating: aluminum coating, zinc coating and zinc-aluminum-mischmetal alloy coating categorized as Type A, Type B, and Type C, respectively. The steel shall undergo heat analysis and product analysis wherein the materials shall conform to the requirements of chemical compositions of carbon, manganese, phosphorus, sulfur, and silicon. Tension test, wrap test and metallic coatings test shall be performed wherein the specimens shall conform to the values of tensile strength, Mandrel diameters and minimum weight of aluminum, zinc or zinc-aluminum-mischmetal alloy per unit area of uncoated wire surface.1.1 This specification covers two finishes of round, metallic coated, hard-drawn, carbon steel spring wire having properties and quality for the manufacture of mechanical springs and wire forms that are not subject to high stress or require high fatigue properties.1.2 The values stated in inch-pound units are to be regarded as the standard. The values stated in SI units are for information purposes only.1.3 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： 590元 加购物车

定价： 590元 加购物车

4.1 The myriad array of particle size analysis techniques available to the modern-day powder technologist is both daunting and confusing. Many of the techniques are applicable only to certain types of materials, and all have limited ranges of applicability with respect to powder particle size. This guide is an attempt to describe and define the applicability of each of the available techniques, so that powder technologists, and others interested in powders, may make informed and appropriate choices in characterizing their materials.4.2 This guide is intended to be used to determine the best and most efficient way of characterizing the particle size distribution of a particular powder material. It may also be used to determine whether a reported powder particle size, or size distribution, was obtained in an appropriate and meaningful way.4.3 Most particle size analysis techniques report particle size in terms of an “equivalent spherical diameter”: the diameter of an ideal spherical particle of the material of interest that would be detected in the same manner during analysis as the (usually irregular-shaped) actual particle under the same conditions. The different techniques must necessarily use different definitions of the equivalent spherical diameter, based on their different operating principles. However, when analyzing elongated particles, the size parameter most relevant to the intended application should be measured; for example, length (maximum dimension).4.4 Reported particle size measurement is a function of both the actual dimension or shape factor, or both, 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 reported particle size results.1.1 This guide covers the use of many available techniques for particle size measurement and particle size distribution analysis of solid particulate (powder) materials, off-line in a laboratory. It does not apply to in-line (on-line) analysis, nor to analysis of liquid droplets or liquid aerosols. The guide is intended to serve as a resource for powder/particle technologists in characterizing their materials.1.2 This guide provides significant detail regarding the numerous particle size analysis methods available. Although this guide is extensive, it may not be all inclusive.1.3 The principle of operation, range of applicability, specific requirements (if any), and limitations of each of the included particle size analysis techniques are listed and described, so that users of this guide may choose the most useful and most efficient technique for characterizing the particle size distribution of their particular material(s).1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.

定价： 590元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

4.1 This practice is of value (1) to the producer of fine particles as a means of reporting particle characteristics with respect to quality control and (2) to the buyer to assure that the particle size and particle size distribution meet his requirements.1.1 This practice for reporting the fineness characteristics of pigments is designed to apply in most cases where well-known methods for determining these particle size characteristics in the subsieve range are employed, such as microscopic, sedimentation, and turbidimetric methods; and partially to absorption and permeability methods.1.2 Laminar, plate-like pigments and composite pigments having a definite bimodal distribution are not considered within the scope of this practice.1.3 Parameters—The fineness characteristics are reported in the following three parameters:1.3.1 Particle Size Parameter.1.3.2 Coarseness Parameter—A parameter descriptive of the coarseness character of the pigment, making use of a limiting value in the subsieve range similar to that used in the sieve ranges.1.3.3 Dispersion Parameter—A parameter descriptive of the uniformity of the particle size distribution.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.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： 515元 加购物车

4.1 These test methods cover procedures for estimating and rules for expressing the average grain size of all metals consisting entirely, or principally, of a single phase. The grain size of specimens with two phases, or a phase and a constituent, can be measured using a combination of two methods, a measurement of the volume fraction of the phase and an intercept or planimetric count (see Section 17). The test methods may also be used for any structures having appearances similar to those of the metallic structures shown in the comparison charts. The three basic procedures for grain size estimation are:4.1.1 Comparison Procedure—The comparison procedure does not require counting of either grains, intercepts, or intersections but, as the name suggests, involves comparison of the grain structure to a series of graded images, either in the form of a wall chart, clear plastic overlays, or an eyepiece reticle. There appears to be a general bias in that comparison grain size ratings claim that the grain size is somewhat coarser (1/2 to 1 G number lower) than it actually is (see X1.3.5). Repeatability and reproducibility of comparison chart ratings are generally ±1 grain size number.4.1.2 Planimetric Procedure—The planimetric method involves an actual count of the number of grains within a known area. The number of grains per unit area, NA , is used to determine the ASTM grain size number, G. The precision of the method is a function of the number of grains counted. A precision of ±0.25 grain size units can be attained with a reasonable amount of effort. Results are free of bias and repeatability and reproducibility are less than ±0.5 grain size units. An accurate count does require marking off of the grains as they are counted.4.1.3 Intercept Procedure—The intercept method involves an actual count of the number of grains intercepted by a test line or the number of grain boundary intersections with a test line, per unit length of test line, used to calculate the mean lineal intercept length, ℓ. ℓ is used to determine the ASTM grain size number, G. The precision of the method is a function of the number of intercepts or intersections counted. A precision of better than ±0.25 grain size units can be attained with a reasonable amount of effort. Results are free of bias; repeatability and reproducibility are less than ±0.5 grain size units. Because an accurate count can be made without need of marking off intercepts or intersections, the intercept method is faster than the planimetric method for the same level of precision.4.2 For specimens consisting of equiaxed grains, the method of comparing the specimen with a standard chart is most convenient and is sufficiently accurate for most commercial purposes. For higher degrees of accuracy in determining average grain size, the intercept or planimetric procedures may be used. The intercept procedure is particularly useful for structures consisting of elongated grains (see Section 16).4.3 In case of dispute, the planimetric procedure shall be the referee procedure in all cases.4.4 No attempt should be made to estimate the average grain size of heavily cold-worked material. Partially recrystallized wrought alloys and lightly to moderately cold-worked material may be considered as consisting of non-equiaxed grains, if a grain size measurement is necessary.4.5 Individual grain measurements should not be made based on the standard comparison charts. These charts were constructed to reflect the typical log-normal distribution of grain sizes that result when a plane is passed through a three-dimensional array of grains. Because they show a distribution of grain dimensions, ranging from very small to very large, depending on the relationship of the planar section and the three-dimensional array of grains, the charts are not applicable to measurement of individual grains.1.1 These test methods cover the measurement of average grain size and include the comparison procedure, the planimetric (or Jeffries) procedure, and the intercept procedures. These test methods may also be applied to nonmetallic materials with structures having appearances similar to those of the metallic structures shown in the comparison charts. These test methods apply chiefly to single phase grain structures but they can be applied to determine the average size of a particular type of grain structure in a multiphase or multiconstituent specimen.1.2 These test methods are used to determine the average grain size of specimens with a unimodal distribution of grain areas, diameters, or intercept lengths. These distributions are approximately log normal. These test methods do not cover methods to characterize the nature of these distributions. Characterization of grain size in specimens with duplex grain size distributions is described in Test Methods E1181. Measurement of individual, very coarse grains in a fine grained matrix is described in Test Methods E930.1.3 These test methods deal only with determination of planar grain size, that is, characterization of the two-dimensional grain sections revealed by the sectioning plane. Determination of spatial grain size, that is, measurement of the size of the three-dimensional grains in the specimen volume, is beyond the scope of these test methods.1.4 These test methods describe techniques performed manually using either a standard series of graded chart images for the comparison method or simple templates for the manual counting methods. Utilization of semi-automatic digitizing tablets or automatic image analyzers to measure grain size is described in Test Methods E1382.1.5 These test methods deal only with the recommended test methods and nothing in them should be construed as defining or establishing limits of acceptability or fitness of purpose of the materials tested.1.6 The measured values are stated in SI units, which are regarded as standard. Equivalent inch-pound values, when listed, are in parentheses and may be approximate.1.7 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.1.8 The paragraphs appear in the following order:Section Number  1Referenced Documents  2Terminology  3  4Generalities of Application  5Sampling  6Test Specimens  7Calibration  8Preparation of Photomicrographs  9Comparison Procedure 10Planimetric (Jeffries) Procedure 11General Intercept Procedures 12Heyn Linear Intercept Procedure 13Circular Intercept Procedures 14Hilliard Single-Circle Procedure  14.2Abrams Three-Circle Procedure  14.3Statistical Analysis 15Specimens with Non-equiaxed Grain Shapes 16Specimens Containing Two or More Phases or Constituents 17Report 18Precision and Bias 19Keywords 20Annexes:   Basis of ASTM Grain Size Numbers Annex A1 Equations for Conversions Among Various Grain Size Measurements Annex A2 Austenite Grain Size, Ferritic and Austenitic Steels Annex A3 Fracture Grain Size Method Annex A4 Requirements for Wrought Copper and Copper-Base Alloys Annex A5 Application to Special Situations Annex A6Appendixes:   Results of Interlaboratory Grain Size Determinations Appendix X1 Referenced Adjuncts Appendix X21.9 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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3.1 When evaluating the particle size information, if the procedures of the data processing are not available, the user of the data must make assumptions concerning the reported data in the event of analytical inconsistencies. In order for different data sets to be compared it is crucial that the parties report the analytical techniques and methods or procedures for evaluating, calculating, compiling or otherwise processing the data to be reported.3.2 Particle size characterization information can be reported in three levels of detail in order to satisfy user's needs.3.2.1 Level 1 applies when only basic information about the material is required, and shall be provided with each shipment. This level represents the minimum information that shall be reported. Level 1 information may be sufficient in such cases as identifying a certain grade of a material or when detailed knowledge of analytical methodology is not needed.3.2.2 Level 2 presumes the need for knowledge of methodology on the user's part and allows the user to make a more informed judgment about the information provided in Level 1.3.2.3 Level 3 provides detailed written procedures to allow duplication of the measurement.3.2.4 Information provided through Levels 2 and 3 will allow users to perform comparative material evaluations among several suppliers, set specifications or define a purchase agreement, perform inter-laboratory studies and most importantly resolve disputes among suppliers and users.3.3 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 This practice covers reporting particle size measurement data.1.2 This practice applies to particle size measurement methods, devices, detail levels, and data formats for dry powders, and wet suspensions of solids, gels, or emulsion droplets. This practice does not pertain to liquid particles.NOTE 1: For information on reporting liquid particle measurement data, refer to Practice E799.1.3 This practice does not concern particle concentration information.1.4 This practice uses SI (Système International) units as standard. State all numerical values in terms of SI units unless specific instrumentation software reports particle size information, including percentiles, indices, and distributions as tabulations and graphs using alternate units. In this case, present both reported and equivalent SI units in the final written report. Refer to Practice E380 for proper usage of SI units.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.

定价： 590元 加购物车

定价： 590元 加购物车

定价： 515元 加购物车