定价： 515元 / 折扣价： 438 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

定价： 843元 / 折扣价： 717 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

4.1 In this test method, a compacted sample is vacuum sealed inside a plastic bag. The density of the sample, SG1, is calculated using a water displacement method, with the sample sealed. With the sample still in water, the bag is cut open. Since the sample is under vacuum and the air voids are evacuated, water will rush in to fill all the water-accessible air voids in the compacted sample. With the saturated weight of sample known, an apparent maximum density, SG2, can be calculated. The difference between SG2 and SG1 is the measure of the amount of water that has penetrated the compacted sample. This difference can be used to determine the fraction of total number of voids that are accessible to water, effective percent porosity or percent effective air voids.4.2 The results obtained from this method can be used to determine the percentage of total air voids in a compacted sample that can be filled with water through surface or interconnected paths within the sample. In general, effective percent porosity should be less than total percent air voids.NOTE 1: The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of Specification D3666 are generally considered capable of competent and objective testing, sampling, inspection, etc. Users of this standard are cautioned that compliance with Specification D3666 alone does not completely ensure reliable results. Reliable results depend on many factors; following the suggestions of Specification D3666 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.4.3 This method can be used for 100 mm [4 in.] and 150 mm [6 in.] diameter cylindrical samples and cubical samples.1.1 This test method covers the determination of effective porosity or effective air voids of compacted mixtures by the use of a vacuum sealing method.1.2 This method can be used for compacted field and laboratory asphalt mixture samples, as well as other compacted samples with well-defined geometrical shapes, such as concrete cylinders, cored rocks, and metal samples.1.3 The results of this test method can be used to determine the degree of interconnectivity of air voids within a sample and can be correlated to permeability of compacted asphalt mixture samples.1.4 A multi-laboratory precision and bias statement for this standard has not been developed at this time. Therefore, this standard should not be used for acceptance or rejection of a material for purchasing purposes.1.5 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 nonconformance with the standard.1.6 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.1.7 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 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

5.1 The significance of this practice is adequately covered in Section 1.1.1 This practice is a general guide for ambient air analyzers used in determining air quality.1.2 The actual method, or analyzer chosen, depends on the ultimate aim of the user: whether it is for regulatory compliance, process monitoring, or to alert the user of adverse trends. If the method or analyzer is to be used for federal or local compliance, it is recommended that the method published or referenced in the regulations be used in conjunction with this and other ASTM methods.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 6.1.5 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

定价： 646元 / 折扣价： 550 元 加购物车

5.1 This test method may be used for the acceptance testing of commercial shipments of yarns and cords. Caution is advised because yarn and cord may contract in length over a period of time due to room temperature retraction. Thermal shrinkage values are reduced proportionately by the amount of room temperature retraction.NOTE 1: Experience, especially with nylon, shows that yarn retraction, which may be observed directly as shortening of length (or indirectly as denier increase), will occur in unrestrained yarn or cord that is not at equilibrium (equilibrium in this case being defined as essentially zero thermal shrinkage yarn or fully relaxed yarn). Normally, retractive forces are present in most wound packages of yarn and cord; thus, unrestrained yarn near the surface is likely, with time, to undergo some retraction. After retraction, such yarns exhibit lower thermal shrinkage values than yarn or cord deeper within the package. The opposite condition of yarn on the surface exists with yarn or cord wound against or near a rigid package core, such as a metal or hardwood wind-up spool. Such core yarn or cord cannot move against this restraint, and thus, will exhibit thermal shrinkage values even several weeks later near to those which were measured immediately from the surface of the freshly wound package. Elevated humidity will accelerate retraction of unrestrained yarn, but moisture content in itself will have little influence on thermal shrinkage. Exposure of untensioned skeins of yarn or cord to 95 to 100 % relative humidity at room temperature for two days and reconditioning under standard laboratory conditions will cause most of the room temperature retraction that is possible within a sample to occur.5.1.1 In case of differences of practical significance in reported test results from two or more laboratories conduct comparative tests to determine if there is a statistical bias between them. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the parties should take a group of test specimens that are as homogeneous as possible and that are from a lot of material of the type in question. The test specimens then should be assigned randomly in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and a probability level chosen by the parties before the testing is begun. If a bias is found, either its cause must be found and corrected, or future test results must be adjusted in consideration of the known bias.5.2 Thermal shrinkage of nylon, polyester, and other fibers is related to the polymer of origin and its manipulation in processing. Thermal shrinkage measurement can be used to control product uniformity.5.3 The level of thermal shrinkage is critical in the user's subsequent operations. For example it can affect the drumset (original length of cord) required in tire building to produce a finished, final tire of a particular size.5.4 Thermal shrinkage is critical to final shape and size of fiber reinforced articles. For example, thermal shrinkage affects final size of V-belts and their ability to maintain tension while running.5.5 This test method is similar to the procedures of Test Methods D885/D885M for the determination of thermal shrinkage of yarns and cords. Shrinkage is measured while the specimen is within an oven and tensioned as specified in Test Methods D885/D885M; however, there are enough vagaries among different units of apparatus for measurement of thermal shrinkage that numerical equivalence between units of different design should not be assumed, even under the same nominal conditions.1.1 This test method covers the measurement of shrinkage of yarns and cords when exposed in a thermal shrinkage oven.1.2 This test method is applicable to yarns and cords made of nylon, polyester, and other polymers not detrimentally affected by the temperature used and with linear densities in the range from 20 to 700 tex [180 to 6300 denier].1.2.1 Yarns or cords for testing may be taken from yarn or cord packages or from fabrics.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. Referee decisions are to use SI units.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. Specific hazard statements are given in Section 8.1.5 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

5.1 Some process catalysts used in refining can be poisoned when trace amounts of sulfur bearing materials are contained in the feedstocks. There are also government regulations as to how much sulfur is permitted to be present in commercial transportation fuels. This test method can be used to determine sulfur in process and downstream distribution streams. It can also be used for purposes of screening and quality control of finished hydrocarbon fuel products.1.1 This test method covers the determination of total sulfur in liquid hydrocarbon based fuel with a final boiling point of up to 450 °C. It is applicable to analysis of natural, processed and final product materials containing sulfur in the range of 4.0 mg/kg to 830 mg/kg (see Note 1).NOTE 1: For liquid hydrocarbons containing less than 4.0 mg/kg total sulfur or more than 830 mg/kg total sulfur, Test Method D5453 may be more appropriate.1.2 This test method is applicable for total sulfur determination in liquid hydrocarbons containing less than 0.35 % (m/m) halogen(s).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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see 4.1, 8.3, and Section 9.1.5 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

定价： 590元 / 折扣价： 502 元 加购物车

This specification establishes the requirements for welded copper for air conditioning and refrigeration service for use in connections, repairs, and alterations. The material of manufacture shall be sheet or strip of Copper Alloy UNS No. C10100, or C10200, or C12000, or C12200 of such purity and soundness as to be suitable for processing into welded tube to meet the properties prescribed. The product shall be manufactured by forming the material into a tubular shape on a suitable forming mill and welded using an automatic process. The product shall be cold worked to the finished size and wall thickness and subsequently annealed to meet the temper properties specified. The material shall conform to the chemical compositional requirements for the Copper UNS No. designation specified. Tensile strength test, expansion test, microscopical examination, hydrogen embrittlement susceptibility, flattening test, reverse bend test, electromagnetic test, and cleanness test shall be made to conform to specified requirements.1.1 This specification establishes the requirements for welded copper tube for air conditioning and refrigeration service for use in connections, repairs, and alterations. The tube shall be made from one of the following coppers:Copper UNS No. Previously Used Designation Type of Copper     C10100 OFE Oxygen-free electronicC10200 OF Oxygen-free without-residual oxidantsC12000 DLP Phosphorus-deoxidized, low-residual phosphorusC12200 DHP Phosphorus-deoxidized, high-residual phosphorus NOTE 1: Fittings used for soldered or brazed connections in air conditioning and refrigeration systems are described in ASME Standard B 16.22.NOTE 2: The assembly of copper tubular systems by soldering is described in Practice B828.NOTE 3: Solders for joining copper tubular systems by described in Specification B32. The requirements for acceptable fluxes for these systems are described in Specification B813.1.2 Copper UNS No. C12200 shall be furnished, unless otherwise specified. The copper tube shall be supplied in annealed coils or drawn temper straight lengths.1.3 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.1.4 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： 590元 / 折扣价： 502 元 加购物车

1.1 This specification covers a coextruded polyethylene composite pressure pipe with a butt welded aluminum tube reinforcement between the inner and outer layers. The inner and outer polyethylene layers are bonded to the aluminum tube by a melt adhesive. Included is a system of nomenclature for the polyethylene-aluminum-polyethylene of raised temperature (PE-RT/AL/PE-RT) pipes, the requirements and test methods for materials, the dimensions and strengths of the component tubes and finished pipe, adhesion tests, and the burst and sustained pressure performance. Also given are the requirements and methods of marking. The pipe covered by this specification is intended for use in air conditioning and refrigeration (ACR) line set systems.1.2 This specification relates only to composite pipes incorporating a butt welded aluminum tube having both internal and external polyethylene layers. The welded aluminum tube is capable of sustaining internal pressures. Pipes consisting of metallic layers not butt welded together and plastic layers other than polyethylene are outside the scope of this specification.1.3 The dimensions in this specification are ID controlled to match that of ACR Copper Tube so that the flowrate and volume remains the same on a size-for-size basis.1.4 Specifications for fittings for use with pipe meeting the requirements of this specification are given in Annex A1.1.5 This specification excludes crosslinked polyethylene-aluminum-crosslinked polyethylene pipes (see Specification F1281).1.6 This specification tests the pipe for service at 60 °C ± 2 °C (140 °F ± 3 °F) or 82 °C ± 2 °C (180 °F ± 3 °F).1.7 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.1.8 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： 590元 / 折扣价： 502 元 加购物车

5.1 Air leakage accounts for a significant portion of the thermal space conditioning load. In addition, it affects occupant comfort and indoor air quality.5.2 In most commercial or industrial buildings, outdoor air is often introduced by design; however, air leakage is a significant addition to the designed outdoor airflow. In most residential buildings, indoor-outdoor air exchange is attributable primarily to air leakage through cracks and construction joints and is induced by pressure differences due to temperature differences, wind, operation of auxiliary fans (for example, kitchen and bathroom exhausts), and the operation of combustion equipment in the building.5.3 The fan-pressurization method is simpler than tracer gas measurements and is intended to characterize the air tightness of the building envelope. It is used to compare the relative air tightness of several similar buildings to identify the leakage sources and rates of leakage from different components of the same building envelope, and to determine the air leakage reduction for individual retrofit measures applied incrementally to an existing building, and to determine ventilation rates when combined with weather and leak location information.1.1 This test method measures air-leakage rates through a building envelope under controlled pressurization and de-pressurization.1.2 This test method is applicable to small temperature differentials and low-wind pressure differential, therefore strong winds and large indoor-outdoor temperature differentials shall be avoided.1.3 This test method is intended to quantify the air tightness of a building envelope. This test method does not measure air change rate or air leakage rate under normal weather conditions and building operation.NOTE 1: See Test Method E741 to directly measure air-change rates using the tracer gas dilution method.1.4 This test method is intended to be used for measuring the air tightness of building envelopes of single-zone buildings. For the purpose of this test method, many multi-zone buildings can be treated as single-zone buildings by opening interior doors or by inducing equal pressures in adjacent zones.1.5 Only metric SI units of measurement are used in this standard. If a value for measurement is followed by a value in other units in parentheses, the second value may be approximate. The first stated value is the requirement.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. For specific hazard statements see Section 7.1.7 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： 646元 / 折扣价： 550 元 加购物车

This specification covers materials proposed for use as air-entraining admixtures to be added to concrete mixtures in the field. The air-entraining admixture shall conform to the requirements such as initial and final time of setting, compressive strength, flexural strength, and length change (maximum shrinkage). Samples shall either be a grab sample (one obtained in a single operation) or a composite sample (one obtained by combining three or more grab samples). For the purpose of this specification, it is recognized that samples shall be taken for quality tests and uniformity tests.1.1 This specification covers materials proposed for use as air-entraining admixtures to be added to concrete mixtures in the field.1.2 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.1.3 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 the standard.

定价： 515元 / 折扣价： 438 元 加购物车