定价： 260元 / 折扣价： 221 元 加购物车

定价： 481元 / 折扣价： 409 元 加购物车

定价： 156元 / 折扣价： 133 元

定价： 481元 / 折扣价： 409 元 加购物车

定价： 481元 / 折扣价： 409 元 加购物车

定价： 481元 / 折扣价： 409 元 加购物车

定价： 605元 / 折扣价： 515 元 加购物车

定价： 481元 / 折扣价： 409 元 加购物车

5.1 This test method measures the molecular weight distribution and molecular weight averages of polyethylene (except LDPE and UHMWPE) and polypropylene resins. Differences in molecular weight and molecular weight distribution significantly affect physical properties, such as morphology, strength, melt flow etc., and as a result, the final properties of products made from these resins.1.1 This test method covers the determination of molecular weight distributions and molecular weight averages of polyolefins by high temperature gel permeation chromatography (GPC). This test method uses commercially available polystyrene standards and equipment and is applicable to polyethylenes (excluding high pressure low density polyethylene (LDPE) and ultra-high molecular weight polyethylene (UHMWPE)) and polypropylenes soluble in 1,2,4-trichlorobenzene (TCB) at 140°C. This test method is not absolute and requires calibration.NOTE 1: Size exclusion chromatography (SEC) often is used as an alternative name for gel permeation chromatography (GPC).NOTE 2: Specific methods and capabilities of users may vary with differences in columns, instrumentation, applications software, and practices between laboratories.NOTE 3: One general method is outlined herein; alternative analytical practices can be followed and are attached in notes where appropriate.NOTE 4: There is no known ISO equivalent to this standard.1.2 The values stated in SI units, based on IEEE/ASTM S1-10, are to be regarded as the 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.

定价： 590元 / 折扣价： 502 元 加购物车

This specification covers the qualification requirements and test methods for field-assembled anodeless riser kits for use with outside diameter controlled polyethylene gas distribution pipes and tubing in sizes of up to 2 IPS. The anodeless riser kits shall be manufactured in accordance with the specified materials, physical properties, and design, which include the riser casings, moisture seals, threads, bend radius, coatings, welding procedures, and riser adapter to riser casing connections. The riser adapter to riser casing connections shall tested by tensile pull testing.1.1 This specification covers requirements and test methods for field-assembled anodeless riser kits for use with outside diameter controlled polyethylene and PA11 gas distribution pipe and tubing in sizes through 2 IPS as specified in Specification D2513 polyethylene and Specification F2945 for PA11.1.2 The test methods described are not intended to be routine quality control tests.1.3 This specification covers the types of field-assembled anodeless riser kits described in 3.3.2.1.4 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 not considered standard.1.5 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures), shall not be considered as requirements of the standard.1.6 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.1.7 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： 515元 / 折扣价： 438 元 加购物车

定价： 156元 / 折扣价： 133 元 加购物车

18.1 For purpose of determining compliance with the specified limits for requirements of the properties listed in Table 5, an observed value or calculated value shall be rounded as indicated in accordance with the rounding method of Practice E29.1.1 This specification establishes the requirements for Type GAS seamless Copper UNS No. C12200 tube for use in above ground natural gas and liquified petroleum (LP) gas fuel distribution systems, commonly assembled with flared fittings or brazed joints.NOTE 1: Tube temper, size, and joining method are determined by installation code requirements.1.2 Units—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 The following safety hazard caveat pertains only to the test method(s) portion, Section 17, of this specification. 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： 590元 / 折扣价： 502 元 加购物车

5.1 Many microplastic particles enter the environment, including ambient waters and drinking water supplies, via wastewater sources resulting from both industrial processes and consumer products. The presence of high percentages of organic particles, including cellulose material originating from toilet paper and chitin-based materials originating from insect exoskeletons, makes visual identification and subsequent quantification of microplastic particles in wastewater difficult.5.2 This test method, associated sampling Practice D8332, and preparation Practice D8333 provide a standardized approach for the preparation of water and, particularly, wastewater samples. The isolation of microplastic particles from interfering contaminants by Practice D8333 enables positive identification and, therefore, quantification of microplastic particles.5.3 Using this test method, microplastic particles are characterized in terms of size, shape, and quantity, allowing for the enumeration of subsequent particle count for a given volume of sample. The method does not provide qualitative identification of plastic composition.1.1 This test method covers the determination of microplastic particle size distribution, shape characterization, and number concentration (particle counts) in sample extracts containing particles between 5 µm and 100 µm. Light is transmitted through a flow cell containing particles in liquid medium. The particles create shadows as they pass through the field of vision of a camera, producing a multitude of images. The images are then used to measure size, shape, and concentration.1.2 This test method is used as a complementary technique for microplastic particle and fiber polymer identification methods infrared microscopy and gas chromatography/mass spectroscopy pyrolysis.1.3 This test method requires that samples are collected according to Practice D8332 and prepared according to Practice D8333 prior to use.1.4 Units—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

5.1 NTA is one of the very few techniques that are able to deal with the measurement of particle size distribution in the nano-size region. This guide describes the NTA technique for direct visualization and measurement of Brownian motion, generally applicable in the particle size range from several nanometers until the onset of sedimentation in the sample. The NTA technique is usually applied to dilute suspensions of solid material in a liquid carrier. It is a first principles method (that is, calibration in the standard understanding of this word, is not involved). The measurement is hydrodynamically based and therefore provides size information in the suspending medium (typically water). Thus the hydrodynamic diameter will almost certainly differ from size diameters determined by other techniques and users of the NTA technique need to be aware of the distinction of the various descriptors of particle diameter before making comparisons between techniques (see 8.7). Notwithstanding the preceding sentence, the technique is routinely applied in industry and academia as both a research and development tool and as a QC method for the characterization of submicron systems.1.1 This guide deals with the measurement of particle size distribution of suspended particles, from ~10 nm to the onset of sedimentation, sample dependent, using the nanoparticle tracking analysis (NTA) technique. It does not provide a complete measurement methodology for any specific nanomaterial, but provides a general overview and guide as to the methodology that should be followed for good practice, along with potential pitfalls.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.

定价： 646元 / 折扣价： 550 元 加购物车

This specification describes requirements and test methods for the qualification of plastic bodied mechanical fittings for use with outside diameter controlled polyethylene (PE) gas distribution pipe, nominal 2 pipe size (IPS) and smaller. In addition, it specifies general requirements of the material from which these fittings are made. Unless otherwise specified, each nominal size of fitting shall be tested. Testing of the thickest wall pipe that the fitting is designed to be used with qualifies the use of that fitting with pipe of lesser wall thickness. In order to determine the overall performance of the mechanical fittings, the following tests shall be performed: elevated temperature sustained pressure test, tensile strength test, temperature cycling test, constant tensile load joint test (in-line joints only), and rotation test (mechanical saddle fittings only).1.1 This specification describes requirements and test methods for the qualification of plastic bodied mechanical fittings for use with outside diameter controlled polyethylene (PE) gas distribution pipe, nominal 2 pipe size (IPS) and smaller complying with Specification D2513. In addition, it specifies general requirements of the material from which these fittings are made.1.2 The test methods described in this specification are not intended to be used as routine quality control tests.1.3 This specification covers the types of mechanical fittings described in 3.2.1.4 The text of this specification references notes and footnotes, which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this specification.1.5 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.1.6 The following safety hazards caveat pertains only to the test method portion, Section 7, of this specification. 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.1.7 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