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5.1 Procedure A is designed to produce moisture diffusion material property data that may be used as follows:5.1.1 To determine approximate exposure times for coupon conditioning in Procedures B-E, Y, and Z;5.1.2 As input to moisture prediction analysis computer codes; or5.1.3 For making qualitative decisions on material selection or performance under environmental exposure to various forms of moisture.5.2 Procedures B-E are designed to condition test coupons to a specified environmental condition or equilibrium state prior to other material property testing (including, but not limited to, mechanical testing).5.3 Procedures Y-Z are designed to determine the loss of moisture content due to removal of a test coupon from the conditioning chamber (such as for strain gauge bonding) or due to heating of the test coupon prior to and during mechanical loading.5.4 A single pair of tests on thin and thick specimens using Procedure A provides the moisture diffusivity constant, Dz, and the moisture equilibrium content, Mm, at the given moisture exposure level and temperature. Multiple tests at differing temperatures are required to establish the dependence of Dz on temperature. Multiple tests at differing moisture exposure levels are required to establish the dependence of Mm on moisture exposure level.NOTE 1: For many polymer matrix composites, the moisture diffusivity is usually only weakly related to relative humidity and is often assumed to be a function only of temperature, usually following an Arrhenius-type exponential relation with inverse absolute temperature. For many of these materials, moisture equilibrium content is only weakly related to temperature and is usually assumed to be a function only of relative humidity (1).5.5 Vapor-exposure testing shall be used to condition the specimen when the in-service environmental condition is a vapor such as humid air. Immersion in a liquid bath should be used to simulate vapor exposure only when apparent absorption properties are desired for qualitative purposes. Properties determined in the latter manner shall be reported as apparent properties.NOTE 2: For many polymer matrix composites, the moisture absorption properties under atmospheric humid conditions are generally not equivalent to exposure either to liquid immersion or to pressurized steam. These latter environments may have different material diffusion characteristics.1.1 This test method covers a procedure for the determination of moisture absorption or desorption properties in the through-the-thickness direction for single-phase Fickian solid materials in flat or curved panel form. Also covered are procedures for conditioning test coupons prior to use in other test methods; either to an essentially moisture-free state, to equilibrium in a standard laboratory atmosphere environment, or to equilibrium in a non-laboratory environment. Also included are procedures for determining the moisture loss during elevated temperature testing, as well as moisture loss resulting from thermal exposure after removal from the conditioning environment, such as during strain gauge bonding. While intended primarily for laminated polymer matrix composite materials, these procedures are also applicable to other materials that satisfy the assumptions of 1.2.1.2 The calculation of the through-the-thickness moisture diffusivity constant in Procedure A assumes a single-phase Fickian material with constant moisture absorption properties through the thickness of the specimen. The validity of the equations used in Procedure A for evaluating the moisture diffusivity constant in a material of previously unknown moisture absorption behavior is uncertain prior to the test, as the test results themselves determine if the material follows the single-phase Fickian diffusion model. A reinforced polymer matrix composite material tested below its glass-transition temperature typically meets this requirement, although two-phase matrices such as toughened epoxies may require a multi-phase moisture absorption model. While the test procedures themselves may be used for multi-phase materials, the calculations used to determine the moisture diffusivity constant in Procedure A are applicable only to single-phase materials. Other examples of materials and test conditions that may not meet the requirements are discussed in Section 6.1.3 The evaluation by Procedure A of the moisture equilibrium content material property does not assume, and is therefore not limited to, single-phase Fickian diffusion behavior.1.4 The procedures used by this test method may be performed, and the resulting data reduced, by suitable automatic equipment.1.5 This test method is consistent with the recommendations of CMH-17 Rev G (1),2 which describes the desirable attributes of a conditioning and moisture property determination procedure.1.6 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.1.6.1 Within the text, the inch-pound units are shown in brackets.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.

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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

定价： 515元 / 折扣价： 438 元 加购物车

4.1 Moisture content is one of the most important variables affecting the properties of wood and wood-based materials. The procedures in these test methods are structured to permit the full range of use from fundamental research to industrial processing. Method A is the reference (primary) standard for determining moisture content of wood and wood-based materials, which is designed for obtaining the most precise values of moisture content consistent with the needs of the user. It provides means of assessing variability contributed by the oven or specimen hygroscopicity, or both. In addition, criteria are described for defining the endpoint in oven-drying. Method B provides relatively simple procedures of measuring moisture content, but generally with a lower precision than Method A. Representativeness of the specimens to the full-size product, including knots, sapwood, and heartwood, needs to be considered. These methods are not recommended for use with treated wood products impregnated with creosote, petroleum, and their solutions where the volatile non-wood chemicals contained in the specimen introduce greater bias than desired in the results.1.1 These test methods cover the determination of the moisture content (MC) of wood, veneer, and other wood-based materials, including those that contain adhesives and chemical additives. The test procedures appear in the following order:    Sections  Method A—Primary Oven-Drying Method 5  Method B—Secondary Oven-Drying Method 61.2 The primary oven-drying method (Method A) is intended as the sole primary method. It is structured for purposes where the highest accuracy or degree of precision is needed (for example, research or calibration).1.3 The secondary oven-drying method (Method B) is intended for the purposes where the primary procedure (Method A) is not desired or justified. Test results in this method are generally less precise than in Method A.1.4 For materials that have been chemically treated or impregnated with creosote, petroleum, and their solutions such that the oven-drying procedures introduce greater bias than desired in the results, other methods, such as AWPA A6, are recommended.1.5 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.1.6 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： 590元 / 折扣价： 502 元 加购物车

4.1 Hand-held meters provide a rapid means of sampling MC of wood-based materials during and after processing to maintain quality assurance and compliance with standards. These measurements are influenced by actual MC, a number of other wood variables, environmental conditions, geometry of the measuring probe circuitry, and design of the meter. The maximum accuracy can only be obtained by an awareness of the effect of each parameter on the meter output and correction of readings as specified by this test method.4.1.1 This test method employs controlled conditions and straight-grain, clear wood specimens to provide measurements that are reproducible in a laboratory. The controlled conditions prevent moisture and temperature gradients in the test specimen.4.1.2 In laboratory calibration, the reference direct moisture measurements (for example, Test Methods D4442) shall be made only in the area of direct measurement of the meter. This minimizes error associated with sampling of differing areas of measurement between this test method and that of the reference (Test Methods D4442).4.2 Most uses of hand-held moisture meters employ correlative (predictive) relationships between the meter reading and wood areas or volumes that exceed that of the direct meter measurement (for example, larger specimens, pieces of lumber, or lots). These correlative relationships are beyond the scope of this test method. (See Practice D7438.)1.1 This test method applies to the measurement of moisture content (MC) of solid wood products, including those containing additives (that is, chemicals or adhesives) for laboratory standardization and calibration of hand-held moisture meters1.2 This test method makes no distinction between meter measurement technologies for standardization and calibration requirements. Provision is made for test specimen size to accommodate specific meters. Appendix X1 provides an explanatory discussion and history corresponding to the mandatory sections. Fundamental measurement technologies are described in Appendix X2 when available.1.2.1 Meters employing differing technologies may not provide equivalent readings under the same conditions. When this test method has been applied, it is assumed that the referenced meter is acceptable unless otherwise specified. Meters shall be calibrated with respect to MC by direct measurement as determined by Test Methods D4442.1.3 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.

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5.1 This test method is useful as a repeatable, nondestructive technique to monitor in-place density and moisture of soil and rock along lengthy sections of horizontal, slanted, and vertical access holes or tubes. With proper calibration in accordance with Annex A1, this test method can be used to quantify changes in density and moisture content of soil and rock.5.2 This test method is used in vadose zone monitoring, for performance assessment of engineered barriers at waste facilities, and for research related to monitoring the movement of liquids (water solutions and hydrocarbons) through soil and rock. The nondestructive nature of the test allows repetitive measurements at a site and statistical analysis of results.5.3 The fundamental assumptions inherent in the density measurement portion of this test method are that Compton scattering and photoelectric absorption are the dominant interactions of the gamma rays with the material under test.5.4 The probe response, in counts, can be converted to wet density by comparing the detected rate of gamma radiation with previously established calibration data (see Annex A1).5.5 The probe count response may also be utilized directly for unitless, relative comparison with other probe readings.5.5.1 For materials of densities higher than that of about the density of water, higher count rates within the same soil type relate to lower densities and, conversely, lower count rates within the same soil type relate to higher densities.5.5.2 For materials of densities lower than the density of water, higher count rates within the same soil type relate to higher densities and, conversely, lower count rates within the same soil type relate to lower densities.5.5.3 Because of the functional inflection of probe response for densities near the density of water, exercise great care when drawing conclusions from probe response in this density range.5.6 The fundamental assumption inherent in the moisture measurement portion of this test is that the hydrogen contained in the water molecules within the soil and rock is the dominant neutron thermalizing media, so increased water content of the soil and rock results in higher count rates of the moisture content system of the instrument.1.1 This test method covers collection and comparison of logs of thermalized-neutron counts and back-scattered gamma counts along horizontal or vertical air-filled access tubes.1.2 For limitations, see Section 6, “Interferences.”1.3 The in situ water content in mass per unit volume and the density in mass per unit volume of soil and rock at positions or in intervals along the length of an access tube are calculated by comparing the thermal neutron count rate and gamma count rates respectively to previously established calibration data.1.4 Units—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. Within the text of this standard, SI units appear first followed by the inch-pound (or other non-SI) units in brackets1.4.1 Reporting the test results in units other than SI shall not be regarded as nonconformance with the standard.1.5 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.1.5.1 The procedures used to specify how data are collected, recorded, and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that should generally 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 analysis methods for engineering design.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 hazards, see Section 8.1.7 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

定价： 618元 / 折扣价： 526 元 加购物车

3.1 The purpose of this test method is to define a procedure for testing components being considered for installation into a high-purity gas distribution system. Application of this test method is expected to yield comparable data among components tested for the purposes of qualification for this installation.1.1 This test method covers testing components for total moisture contribution to a gas distribution system at ambient temperature. In addition, the test method allows testing at elevated ambient temperatures as high as 70°C and of the component moisture capacity and recovery.1.2 This test method applies to in-line components containing electronics grade materials such as those used in semiconductor gas distribution systems.1.3 Limitations: 1.3.1 This test method is limited by the sensitivity of current instrumentation, as well as by the response time of the instrumentation. This test method is not intended to be used for test components larger than 12.7-mm (1/2-in.) outside diameter nominal size. This test method could be applied to larger components; however, the stated volumetric flow rate may not provide adequate mixing to ensure a representative sample. Higher flow rates may improve the mixing but excessively dilute the sample.1.3.2 This test method is written with the assumption that the operator understands the use of the apparatus at a level equivalent to six months of experience.1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.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. Specific hazard statements are given in Section 5.1.6 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： 0元 / 折扣价： 0 元

定价： 590元 / 折扣价： 502 元 加购物车

3.1 Gasket materials undergo several processing steps from point of manufacture to installation in a flange. Many applications require close control of dimensional change. An accurate test method for determining the relative stability of various materials is needed for design and quality assurance purposes. This test method is useful towards that end. It simulates the extreme storage conditions that a material may undergo prior to installation. Samples are allowed unrestricted expansion or contraction, and so this test method should not be used to predict behavior clamped in a flange or other applications, or during specific processing steps.3.2 This test method measures linear change, and may need to be modified if the test specimen is not flat, homogeneous, or free of voids.1.1 This test method covers a procedure to determine the stability of a gasket material to linear dimensional change due to hygroscopic expansion and contraction. It subjects a sample to extremes, that is, oven drying and complete immersion in water, that have shown good correlation to low and high relative humidities.21.2 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

4.1 The purpose of this test is to obtain, by means of a specified laboratory procedure, the values of the equilibrium moisture content at higher RH levels ((≈ 95 to 100%). These values are used either as means to characterize the material or as material characteristics needed as input to appropriate computer models that can simulate wetting or drying potential of individual building materials or material assemblies under specified environmental conditions.1.1 This test method specifies a laboratory procedure for the determination of the water retention curve (or moisture storage capacity) of porous building materials at very high relative humidity (RH) levels (≈ 95 to 100% RH) corresponding to the capillary moisture region of the sorption isotherm. This is achieved by using the pressure plate test apparatus. This technique was originally developed to study soil moisture content and eventually had been adapted to building construction materials.1.2 At higher RH levels (≈ 95 to 100% RH) of the sorption isotherm (see Test Method C1498), use of climatic chamber is not an option. This technique uses overpressure to extract water out of the pore structure of porous materials until equilibrium between the moisture content in the specimens and the corresponding overpressure is achieved. Using the pressure plate extractors, equilibrium can only be reached by desorption.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.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.

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5.1 This recommended practice furnishes directions for the sampling of wool of the various forms indicated in Section 1, in order that correct probability statements may be made about the relationship between the sample mean and the population mean. If these statements are to be correct, certain conditions, which are stated, must hold.5.2 This recommended practice requires that a deliberate act of randomization be performed so that all potential sampling units have approximately the same chance of being taken and no sampling unit is deprived of its chance of being taken.5.3 In any case where insufficient information about the variability of the sampling units within the lot is available, directions are given for calculating confidence limits for the sample mean so that a correct probability statement can still be made.1.1 This practice covers the design of a sampling plan to be used to obtain samples for the determination of the moisture content of grease wool, scoured wool, carded wool, garnetted wool, wool top and intermediate products, and rovings.1.2 Directions are given for the designation of sampling units, calculation of the number of sampling units required to achieve a preselected precision and confidence level or, alternatively, for calculating the confidence limits for the mean based on the variability of the sample tested.NOTE 1: This practice for devising a sampling plan is intended for use in connection with Test Method D1576 or Test Method D2462. The sampling of raw wool for the determination of clean wool fiber present is covered in Practice D1060.1.3 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 / 折扣价： 502 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车