5.1 The determination of class group composition of automotive spark-ignition fuels as well as quantification of various individual species such as oxygenates and aromatics in automotive fuels is useful for evaluating quality and expected performance, as well as compliance with various governmental regulations.1.1 This test method is a standard procedure for the determination in percent mass or percent volume of hydrocarbon group types (paraffins, isoparaffins, olefins, naphthenes, aromatics), methanol, ethanol, benzene, toluene, ethylbenzene, xylenes, naphthalene, and methylnaphthalenes in automotive spark-ignition engine fuels using gas chromatography and vacuum ultraviolet detection (GC-VUV).1.1.1 The concentration ranges for which precision has been determined are as follows:Property Units Applicable RangeParaffins % Volume 3.572 to 23.105Isoparaffins % Volume 22.697 to 71.993Olefins % Volume 0.011 to 44.002Olefins % Mass 0.027 to 41.954Naphthenes % Volume 0.606 to 18.416Aromatics % Volume 14.743 to 58.124Methanol % Volume 0.063 to 3.426Ethanol % Mass 0.042 to 15.991Benzene % Volume 0.09 to 1.091Toluene % Volume 0.698 to 31.377Ethylbenzene % Volume 0.5 to 3.175Xylenes % Volume 3.037 to 18.955Naphthalene % Volume 0.019 to 0.779Methylnaphthalenes % Volume 0.21 to 1.4841.1.2 This test method may be applicable to other concentration ranges, to other properties, or to other hydrocarbon streams, however precision has not been determined.1.2 Individual hydrocarbon components are typically not baseline-separated by the procedure described in this test method, that is, some components will coelute. The coelutions are resolved at the detector using VUV absorbance spectra and deconvolution algorithms.1.3 While this test method reports percent mass and percent volume for several specific components that may be present in automotive spark-ignition engine fuel, it does not attempt to speciate all possible components that may occur in automotive spark-ignition engine fuel. In particular, this test method is not intended as a type of detailed hydrocarbon analysis (DHA).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. See specific hazard statements in subsection 8.4 and Section 9.1.6 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 / 折扣价： 550 元 加购物车

This specification deals with carbon steel girder rails of plain, grooved, and guard types. Materials considered in this specification are grouped into three classes (Class A, B, and C) based on type, weight and chemistry (carbon, manganese, phosphorus, and silicon compositions). Steel samples shall be melt processed by either open-hearth, basic-oxygen, or electric furnace, and may be cast by a continuous process or in ingots. Material specimens shall undergo product analysis and tests, and shall conform to required chemical and physical attributes such as chemical composition, Brinell hardness, weight, length, sectioning, end finishing, drilling and punching specifications. Rails shall be finished by cold straightening in a press or roller machine to remove twists, waves and kinks. Final products shall be marked either by brand and stamp, paint, or bar code.1.1 This specification covers carbon steel girder rails2 of three classes based on type or type and weight, and chemistry defined as follows and in Table 1.1.1.1 Unless otherwise specified by the purchaser, girder-guard rails shall be Class A.1.1.2 Plain and grooved-girder rails under 135 lb/yd (67.1 kg/m) in weight shall be specified by the purchaser as either Class A or Class B.1.1.3 Plain and grooved-girder rails of 135 lb/yd in weight and heavier shall be Class C, unless otherwise specified.1.2 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.1.3 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： 515元 / 折扣价： 438 元 加购物车

This specification covers the detailed requirements for specified grades of flat-rolled, grain-oriented, fully processed low-carbon silicon-iron electrical steels, whose low core loss and high permeability in the direction of rolling have been achieved by appropriate metallurgical processing. These steels are primarily used in transformer cores operating at moderate to high magnetic flux densities at commercial power frequencies. These steels may be acquired in any of four conditions a.) conventional grain-oriented tested at 15 kG (1.5 T), b.) conventional grain-oriented tested at 17 kG (1.7 T), c.) high-permeability grain-oriented tested at 17 kG (1.7 T) and d.) laser-scribed high-permeability grain-oriented tested at 17 kG (1.7 T). These steels can be purchased in a number of combinations of material form and surface type or treatment. This specification explains in detail, the available forms, thicknesses and magnetic performance.1.1 This specification covers the detailed requirements to which the specified grades of flat-rolled, grain-oriented, fully processed electrical steels shall conform. These steels are used primarily in transformer cores operating at moderate to high magnetic flux densities at commercial power frequencies (50 and 60 Hz).1.2 These grain-oriented electrical steels are low-carbon, silicon-iron alloys with a silicon content of approximately 3.2 % in which low core loss and high permeability in the direction of rolling have been achieved by appropriate metallurgical processing.1.3 The electrical-steel grades described in this specification include (1) conventional grain-oriented electrical steel tested at 1.5 T (15 kG) in accordance with Test Method A343/A343M, (2) conventional grain-oriented electrical steel tested at 1.7 T (17 kG) in accordance with Test Method A343/A343M, (3) high-permeability grain-oriented electrical steel tested at 1.7 T (17 kG) in accordance with Test Method A343/A343M, and (4) laser-scribed high-permeability grain-oriented electrical steel tested at 1.7 T (17 kG) in accordance with Test Methods A804/A804M.1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to customary (cgs-emu and inch-pound) units which 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 and health 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 / 折扣价： 502 元 加购物车

定价： 0元 / 折扣价： 0 元

5.1 Accurate quantitative compositional information on hydrocarbon types can be useful in determining the effects of processes in the production of various finished fuels. Producers may require additional determinations such as n-paraffins, i-paraffins, naphthenes, and aromatics for process optimization. This information also may be useful for indicating the quality of fuels and for assessing the relative combustion properties of finished fuels. This test method can be used to make such determinations.1.1 This test method covers the quantitative determination of total n-paraffins, total i-paraffins, total naphthenes (cycloparaffins), total one ring (1R) and total two ring plus (2R+) aromatic hydrocarbons in hydrocarbon liquids having a boiling point between 36 °C and 343 °C by GCxGC (flow modulated comprehensive two-dimensional gas chromatography). The method has been applied to aviation turbine fuels and is applicable to other low olefinic fuels in the stated boiling point range.1.2 This test method has an interim precision. An expanded full interlaboratory study is to be completed in <5 years. The test method working concentration ranges in mass percent for which the interim precision has been determined are as follows:Hydrocarbon Type Lower limit(mass percent) Upper limit(mass percent)Total i-paraffins 22.0 24.3Total n-paraffins 19.0 21.9Total naphthenes (cycloparaffins) 34.3 36.7Total one ring aromatics 18.7 21.8Total two ring plus aromatics 0.5 1.91.3 This test method is applicable to other group type concentration ranges, to other hydrocarbon types such as selected individual components, for example, benzene, toluene, or n-paraffins by carbon number, or to other hydrocarbon streams; however, precision has not been determined at this time. A future ILS will include a variety of sample types and extend the reporting.1.4 This test method is not intended to determine unsaturated hydrocarbons, such as olefins, content which may interfere with the cycloparaffins; this test method is applicable to samples with < 1% by mass total olefins as determined by D1319.1.5 This test method is not intended to determine FAME (fatty acid methyl esters). For such applications, Test Method D7797, IP 585, or equivalent test methods are available.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.7 This standard test method does not mandate or describe a specific software package for data processing and display. Any commercially available GCxGC software used for data processing and display shall meet the requirements for the calculation of the results. Appendix X1 provides some guidelines.1.8 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.1.9 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.

定价： 843元 / 折扣价： 717 元 加购物车

5.1 These procedures can be used to generate microplastic particles as a simulation of microplastic particles found in the natural environment. Suitable uses may include evaluation of microplastic detection and imaging methods. Use of reference samples will support estimation of ambient and flux concentrations in drinking water, wastewater and natural environments, investigations of microplastic particle degradation, and ingestion of microplastics by animals in the contexts of food safety and human health risk assessment.1.1 This practice describes manufacturing methods to create microplastic particles from pellets of common polymers and the preparation of microplastic reference samples for calibration and proficiency evaluation of microplastic collection practices, preparation practices, and identification methods.1.2 This practice does not describe methods for controlling or characterizing the shapes of particles. The procedures have been observed to yield irregularly shaped particles, the use of which in many cases will serve to remove the analytical bias inherent with using distinctive manufactured spherical beads. Other procedures should be used if spheres or elongated fibers are desired.1.3 This practice does not describe handling procedures for waste generated when executing the procedures described herein. It is the responsibility of the user of this practice to follow applicable laws and regulations when manufacturing and disposing of microplastic particles, and to establish appropriate procedures to minimize the amount of waste generated.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 / 折扣价： 502 元 加购物车

This specification covers the requirements to which flat-cast, amorphous, semi-processed, iron-base magnetic core alloys must conform. These alloys shall be produced by a rapid-quenching, direct-casting process, resulting in metals with noncrystalline structure. The alloys shall be made to meet specified maximum core-loss values and shall be intended primarily for commercial power frequency applications. Desirable core-loss and permeability characteristics shall be developed by further heat treatment in a magnetic field. Amorphous magnetic core alloys are normally composed of iron with small amounts of alloying elements such as boron and silicon. There are no specific chemical requirements in this specification. Material produced to this specification shall conform to the required physical and mechanical properties such as density, ductility, thermal expansion, thermal conductivity, volume resistivity, lamination factor, surface, edge, and pinholes. The alloy shall also conform to the magnetic property requirements such as DC induction, DC coercive field strength, DC residual induction, core loss, and specific exciting power.1.1 This specification covers the general requirements to which flat-cast, amorphous, semi-processed, iron-base magnetic core alloys must conform.1.2 These alloys are produced by a rapid-quenching, direct-casting process, resulting in metals with noncrystalline (amorphous) structure. The metallic alloys are made to meet specified maximum core-loss values and are intended primarily for commercial power frequency (50- and 60-Hz) applications in magnetic devices. Desirable core-loss and permeability characteristics are developed by further heat treatment in a magnetic field by the user. The heat treatment typically consists of heating the material to a temperature of 320 to 420°C in a dry, inert atmosphere for 5 to 10 min, although soak times of up to 2 h may be used for large transformer cores. A magnetic field may be required during annealing as designated by the producer. Exact optimum annealing conditions depend on the processing of the material and the size and shape of the device.1.3 Some of these alloys are sensitive to mechanical stress. Care must be exercised in minimizing any stresses on the material in its final application, otherwise, its magnetic properties will be significantly impaired.1.4 This specification is developed to aid in the purchase of transformer grade amorphous strip. It provides the chemical, physical, and magnetic parameters and procedures for quality control tests.1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are numerical conversions to customary (cgs and inch-pound) units which are provided for information only and are not considered standard.1.6 This standard does not purport to address the safety concerns 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.1.7 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 / 折扣价： 502 元 加购物车