5.1 Low operating temperature fuel cells such as proton exchange membrane fuel cells (PEMFCs) require high purity hydrogen for maximum performance. The following are the reported effects (SAE TIR J2719) of the compounds determined by this test method.5.2 Carbon Dioxide (CO2), acts largely as a diluent; however, in the fuel cell environment, CO2 can be transformed into CO.5.3 Water (H2O), is an inert impurity, as it does not affect the function of a fuel cell stack; however, it provides a transport mechanism for water-soluble contaminants, such as Na+ or K+. In addition, it may form ice on valve internal surface at cold weather or react exothermally with metal hydride used as hydrogen fuel storage.5.4 Inert Gases (N2 and Ar), do not normally react with fuel cell components or fuel cell system and are considered diluents. Diluents can decrease fuel cell stack performance.5.5 Oxygen (O2), in low concentrations is considered an inert impurity, as it does not adversely affect the function of a fuel cell stack; however, it is a safety concern for vehicle on board fuel storage as it can react violently with hydrogen to generate water and heat.1.1 This test method describes a procedure primarily for the determination of carbon dioxide, argon, nitrogen, oxygen, and water in high pressure fuel cell grade hydrogen by gas chromatograph/mass spectrometer (GC/MS) with injection of sample at the same pressure as sample without pressure reduction, which is called “Jet Pulse Injection.” The procedures described in this method were designed to measure carbon dioxide at 0.5 micromole per mole (ppmv), Argon 1 ppmv, nitrogen 5 ppmv, oxygen 2 ppmv, and water 4 ppmv.1.2 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.3 The mention of trade names in standard does not constitute endorsement or recommendation for use. Other manufacturers of equipment or equipment models can be used.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： 0元 / 折扣价： 0 元

1.1 This classification and subsequent line callout (specification) cover styrenic block copolymer thermoplastic elastomer materials for injection molding and extrusion. Copolymers consist of polystyrene segments bound to rubbery segments. The rubbery segments may be saturated or unsaturated. Compounding ingredients may be present as necessary for the application. The compounding ingredients may consist of reinforcements, resins, plasticizers, fillers, stabilizers, and colorants. Recycled styrenic thermoplastic elastomers are not covered in this classification.1.2 The properties included in this classification are those required to identify the compositions covered. There may be other requirements necessary to identify particular characteristics that are important to specialized applications. These may be described by using the suffixes specified in Section 5.1.3 The values stated in SI units, as detailed in IEEE/ASTM SI 10, are to be regarded as the standard.Note 1--There is no equivalent ISO standard.

定价： 0元 / 折扣价： 0 元

定价： 590元 / 折扣价： 502 元 加购物车

5.1 It is well known that plastic test specimens molded under different conditions can have significantly different properties. This practice is designed to minimize those differences by establishing operating protocols without being unnecessarily restrictive.5.2 Always refer to the ASTM material specification or ISO designation for the material for recommended molding conditions. If not available, consult the material supplier.5.3 This practice requires the use of adequate quantities of plastic material to find desirable operating conditions and to make the desired test specimens.1.1 This practice covers the general principles to be followed when injection molding test specimens of thermoplastic molding and extrusion materials. This practice is used to obtain uniformity in methods of describing the various steps of the injection molding process and to set up uniform methods of reporting these conditions. The exact conditions required to prepare suitable specimens will vary for each plastic material. Any requirements or recommendations in the material specification that differ from this standard take precedence over those in this standard. Always consult the referenced material document for specimen preparation. If no referenced document exists, then consult the material supplier for specimen preparation guidance and note such in the test report.1.2 The methodology presented assumes the use of reciprocating screw injection molding machines.1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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.NOTE 1: This practice is equivalent to the following parts of ISO 294: Plastics—Injection Moulding of Test Specimens of Thermoplastic Materials; 294-1: Part 1—General Principles and Multipurpose Test Specimens (ISO Type A Mould) and Bars (ISO Type B Mould); ISO 294-2: Part 2—Small Tensile Bars (ISO Type C Mould); ISO 294-3: Part 3—Plates (ISO Type D Moulds).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 / 折扣价： 502 元 加购物车

This classification system covers nylon injection and extrusion materials. Nylon materials are classified into groups according to their composition. Groups are further classified into classes and grades. Grades are identified by a single letter that indicates the reinforcement or filler used and two digits, in multiples of 5, which indicate the nominal quantity in weight percent. Specific requirements for variations of nylon materials shall be shown by a six-character designator. Suffixes shall be used for those properties not covered by basic requirements. Specific suffix requirements shall always take precedence over basic requirements. Tensile strength, flexural strength, Izod impact resistance, deflection temperature, and density shall be done on test pieces based on injection molded ISO 3167 type multipurpose test specimens. Conditioning, preparation, testing, inspection, packaging, and marking shall be in conformance to the requirements in this standard classification system.1.1 This classification system covers nylon materials suitable for injection molding and extrusion. Some of these compositions are also suitable for compression molding and application from solution.1.2 The properties included in this classification system are those required to identify the compositions covered. There may be other requirements necessary to identify particular characteristics important to specialized applications. These may be specified by using the suffixes as given in Section 5.1.3 This classification system and subsequent line call-out (specification) are intended to provide a means of calling out plastic materials used in the fabrication of end items or parts. It is not intended for the selection of materials. Material selection should be made by those having expertise in the plastic field after careful consideration of the design and the performance required of the part, the environment to which it will be exposed, the fabrication process to be employed, the costs involved, and the inherent properties of the material other than those covered by this classification system.1.4 The values stated in SI units are to be regarded as the standard.1.5 The following precautionary caveat pertains only to the test methods portion, Section 11, of this classification system. 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.NOTE 1: There is no known ISO equivalent to this standard.NOTE 2: This classification system is being revised to include international 4-mm specimens and test procedures as the standard for compliance. The 3.2-mm specimens; test methods; and Tables PA, A, and B are included in Appendix X3 as a reference for those wishing to use them. It is recommended that the material manufacturer be consulted on all call-outs against this classification system.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

5.1 Test Method—The constant pressure injection test method is used to determine the transmissivity and storativity of low-permeability formations surrounding packed-off intervals. Advantages of the method are: (1) it avoids the effect of well-bore storage, (2) it may be employed over a wide range of rock mass permeabilities, and (3) it is considerably shorter in duration than the conventional pump and slug tests used in more permeable rocks.5.2 Analysis—The transient water flow rate data obtained using the suggested test method are evaluated by the curve-matching technique described by Jacob and Lohman (1)4 and extended to analysis of single fractures by Doe et al. (2). If the water flow rate attains steady state, it may be used to calculate the transmissivity of the test interval (3).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 assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.NOTE 3: The function of wells in any unconfined setting in a fractured terrain might make the determination of k problematic because the wells might only intersect tributary or subsidiary channels or conduits. The problems determining the k of a channel or conduit notwithstanding, the partial penetration of tributary channels may make determination of a meaningful number difficult. If plots of k in carbonates and other fractured settings are made and compared, they may show no indication that there are conduits or channels present, except when with the lowest probability one maybe intersected by a borehole and can be verified, such problems are described by Worthington (4) and Smart, 1999 (5). Additional guidance can be found in Guide D5717.1.1 This test method covers a field procedure for determining the transmissivity and storativity of geological formations having permeabilities lower than 10−3 μm2 (1 millidarcy) using constant head injection.1.2 The transmissivity and storativity values determined by this test method provide a good approximation of the capacity of the zone of interest to transmit water, if the test intervals are representative of the entire zone and the surrounding rock is fully water-saturated.1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.NOTE 1: Unit Conversions—The permeability of a formation is often expressed in terms of the unit darcy (non-SI). A porous medium has a permeability of 1 Darcy when a fluid of viscosity 1 cp (1 mPa·s) flows through it at a rate of 1 cm3/s (10–6 m3/s)/1 cm2 (10–4 m2) cross-sectional area at a pressure differential of 1 atm (101.4 kPa)/1 cm (10 mm) of length. One Darcy corresponds to 0.987 μm2. For water as the flowing fluid at 20°C, a hydraulic conductivity of 9.66 μm/s corresponds to a permeability of 1 Darcy. Permeabilities may also be expressed as millidarcy (md), which is not an SI unit.1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.4.1 The procedures used to specify how data are collected/recorded or 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 the 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 be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering design.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 classification system covers reinforced and filled poly(phenylene sulfide) (PPS) materials suitable for injection molding and extrusion. This classification system is not intended for the selection of materials, but only as a means to call out plastic materials to be used for the manufacture of parts. The physical properties of the materials must meet the required tensile strength, flexural modulus, Izod impact strength, flexural strength, and density.1.1 This classification system covers reinforced and filled poly(phenylene sulfide) materials suitable for injection molding and extrusion.1.2 This classification system is not intended for the selection of materials, but only as a means to call out plastic materials to be used for the manufacture of parts. The selection of these materials shall be made by personnel with expertise in the plastics field where the environment, inherent properties of the materials, performance of the parts, part design, manufacturing process, and economics are considered.1.3 The properties included in this classification system are those required to identify the compositions covered. If necessary, other requirements identifying particular characteristics important to specific applications shall be designated by using the suffixes given in Section 5 or Classification System D4000.1.4 The values stated in SI units are to be regarded as the standard.NOTE 1: There is no known ISO equivalent to this standard.NOTE 2: ASTM Standard D6358 provides a classification system for the same materials covered in this standard, along with additional PPS materials, with the major difference being its use of ISO test methods, versus the use of ASTM test methods in this standard. The user of this standard is encouraged to evaluate switching to the use of Standard D6358 as it is more up to date with current practices.1.5 This precautionary statement pertains only to the test method portion of this classification system, Section 12. 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

定价： 777元 / 折扣价： 661 元 加购物车

4.1 In order to calculate volatile organic content (VOC) in waterborne paints, it is necessary to know the water content. This gas chromatographic test method provides a relatively simple and direct way to determine water content.1.1 This test method is for the determination of the total water content of waterborne paints. It has been evaluated for latex systems (styrene-butadiene, poly(vinylacetate)-acrylic, acrylic), epoxy acrylic resin systems and acrylic systems. The established working range of this test method is from 15 % to 90 %. There is no reason to believe that it will not work outside of this range.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.

定价： 515元 / 折扣价： 438 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

定价： 646元 / 折扣价： 550 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

定价： 1058元 / 折扣价： 900 元 加购物车

定价： 983元 / 折扣价： 836 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车