定价： 515元 加购物车

定价： 515元 加购物车

5.1 This test method allows specification of the density calibration procedures to be used to calibrate and perform material density measurements using CT image data. Such measurements can be used to evaluate parts, characterize a particular system, or compare different systems, provided that observed variations are dominated by true changes in object density rather than by image artifacts. The specified procedure may also be used to determine the effective X-ray energy of a CT system.5.2 The recommended test method is more accurate and less susceptible to errors than alternative CT-based approaches, because it takes into account the effective energy of the CT system and the energy-dependent effects of the X-ray attenuation process.FIG. 1 Density Calibration Phantom5.3 This (or any) test method for measuring density is valid only to the extent that observed CT-number variations are reflective of true changes in object density rather than image artifacts. Artifacts are always present at some level and can masquerade as density variations. Beam hardening artifacts are particularly detrimental. It is the responsibility of the user to determine or establish, or both, the validity of the density measurements; that is, they are performed in regions of the image which are not overly influenced by artifacts.5.4 Linear attenuation and mass attenuation may be measured in various ways. For a discussion of attenuation and attenuation measurement, see Guide E1441 and Practice E1570.1.1 This test method covers instruction for determining the density calibration of X- and γ-ray computed tomography (CT) systems and for using this information to measure material densities from CT images. The calibration is based on an examination of the CT image of a disk of material with embedded specimens of known composition and density. The measured mean CT values of the known standards are determined from an analysis of the image, and their linear attenuation coefficients are determined by multiplying their measured physical density by their published mass attenuation coefficient. The density calibration is performed by applying a linear regression to the data. Once calibrated, the linear attenuation coefficient of an unknown feature in an image can be measured from a determination of its mean CT value. Its density can then be extracted from a knowledge of its mass attenuation coefficient, or one representative of the feature.1.2 CT provides an excellent method of nondestructively measuring density variations, which would be very difficult to quantify otherwise. Density is inherently a volumetric property of matter. As the measurement volume shrinks, local material inhomogeneities become more important; and measured values will begin to vary about the bulk density value of the material.1.3 All values are stated in 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.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 These test methods provide accurate and reliable methods to measure the relative density of gaseous fuels on an intermittent or continuous basis. These measurements are frequently used for regulatory or contract compliance custody transfer and process control.1.1 These test methods cover the determination of relative density of gaseous fuels, including liquefied petroleum gases, in the gaseous state at normal temperatures and pressures. The test methods specified are sufficiently varied in nature so that one or more may be used for laboratory, control, reference, gas measurement, or in fact, for any purpose in which it is desired to know the relative density of gas or gases as compared to the density of dry air at the same temperature and pressure.1.2 The procedures appear in the following sections:  SectionMethod A, Ac-Me Gravity Balance 7 – 9Method B, Ranarex Recording and Indicating Gravitometer 10-11Method C, UGC Gravitometer 12 – 14NOTE 1: The test methods and apparatus described herein are representative of methods and apparatus used broadly in industry. Manufacturer's instructions for specific models should be consulted for further details and as supplements to the information presented here. In addition to instrumentation described below additional equally accurate and satisfactory instruments may be available.1.3 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 and health 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 加购物车

4.1 This test method provides a method for determining the packed density of a bed of granular activated carbon. Determination of the packed density is essential when designing vessels to hold the material and for ordering purposes when procuring materials to fill existing vessels.1.1 This test method covers the determination of the apparent density of granular activated carbon. For purposes of this test method, granular activated carbon is defined as a minimum of 90 % being larger than 80 mesh.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： 515元 加购物车

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3.1 This test method provides a controlled laboratory test for the determination of quantitative volumes of emulsified asphalt for use in bills of lading, invoicing, and application rates.1.1 This test method covers the determination of density of emulsified asphalt used in highway construction. This unit is computed by determining the mass of an emulsified asphalt contained in a standard measure of known volume.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 test method 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.

定价： 515元 加购物车

4.1 The density of polyethylene is a conveniently measurable property which is frequently useful as a means of following physical changes in a sample, as an indication of uniformity among samples, and as a means of identification.4.2 This test method is designed to yield results with a precision of ±0.08 % or better.1.1 This test method covers the determination of the density of polyethylene through the utilization of ultrasound equipment.1.2 This test method is based on the distinct behaviors of the amorphous and crystalline phases of polyethylene in response to ultrasound. Polyethylene shall be viewed as a composite structure where high-density crystalline regions are connected by lower-density amorphous material. The ratio of crystalline to amorphous material determines the final density of the material. The amorphous and crystalline phases exhibit very distinct behaviors with regard to the propagation of sound waves. The propagation characteristics in the composite will depend on the relative amount of the two phases (the degree of crystallinity).1.3 Inorganic materials increase density as measured by Test Methods D792 and D1505, but they have little or no effect on ultrasonic density. The ultrasonic measurement is basically a base resin density.1.4 The values stated in SI units are to be regarded as the standard. The values 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.NOTE 1: There is no known ISO equivalent to this standard.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： 515元 加购物车

5.1 Density is a fundamental physical property that can be used in conjunction with other properties to characterize the sandwich core. Most sandwich core structural properties, such as strength and stiffness, are proportional to the density.5.2 This test method provides a standard method of obtaining sandwich core density data for design properties, material specifications, research and development applications, and quality assurance.5.3 Factors that influence the density and shall therefore be reported include the following: core material, methods of material fabrication, core geometry (nominal cell size), specimen geometry, specimen preparation, methods of weight and dimensional measurement, specimen conditioning, and moisture content during weight and dimensional measurements.1.1 This test method covers the determination of the density of sandwich construction core materials. Permissible core material forms include those with continuous bonding surfaces (such as balsa wood and foams) as well as those with discontinuous bonding surfaces (such as honeycomb).1.2 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.1.2.1 Within the text, the inch-pound units are shown in brackets.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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4.1 Option A for bundle weighing of Test Method D1577 is used in the trade for acceptance testing of commercial shipments. Option B for single-fiber weighing and Option C for the vibroscope may be used for acceptance testing (see Section 37); however, caution is advised when using Option B or Option C because between-laboratory precision information is incomplete. Comparative tests as directed in 4.1.1 may be advisable.4.1.1 In case of dispute arising from differences in reported test results when using Test Method D1577 for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of samples that are as homogeneous as possible and that are from a lot of material of the type in question. These samples should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using the appropriate statistical analysis and a probability level chosen by the two parties before testing is begun. If a bias is found, either the cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results for that material with consideration to the known bias.4.2 Option A for bundle weighing is generally considered to be the referee procedure for acceptance testing.4.3 Option A is not recommended for measurement of linear density of blends of production fibers having different nominal linear densities.4.4 The accuracy of the linear density values obtained by Options A and B is dependent upon the accuracy with which the fibers can be cut and weighed.NOTE 2: On short staple fiber, an accuracy in cutting of 1.0 % is difficult to obtain. This problem is further complicated if crimp is present in the fibers.4.4.1 The accuracy of weighing can be controlled by the number of fibers composing the bundle. However, with short fiber of low linear density the number of fibers to be counted becomes prohibitive unless the bundle mass is kept low.4.5 Options A and B are fundamental procedures which are used to standardize the vibroscope equipment used in Options C1 and C2.4.6 Test Method Options B and C are most useful for the measurement of linear density of single fibers when further tests upon the same test specimen are required, for example, tension tests and adjustment of the data obtained for the linear density of the test specimen. These options offer advantages in accuracy and ease of operations over calculation from specific gravity and microscopically measured cross-sectional area.4.7 Additional information specific to Option C is in Section 26.1.1 These test methods cover the measurement of mass per unit length (linear density) of textile fibers and filaments. Direct weighing and vibroscope procedures with modifications for crimped and uncrimped fibers are included. The options and sections are listed below.  Option Sections   A—Fiber Bundle Weighing  7 – 15  B—Single-Fiber Weighing 16 – 23  C—Vibroscope, General 24 – 30    35 and 36  C1—Uncrimped Fibers 31 and 32  C2—Crimped Fibers 33 and 34  Precision and Bias 37 and 38NOTE 1: For linear density of short lengths of yarn, refer to Test Method D1059. For cotton linear density, refer to Test Methods D1769 and D2480. For measurement of wool diameter, refer to Test Methods D1282, D2130, and D3510.1.2 The crimp, taper, and cross-sectional shape of the fiber may influence the linear density measured by single-fiber weighing and vibroscope.1.3 These test methods measure the linear density of fibers with moisture in equilibrium with the standard atmosphere for testing textiles. The fiber moisture under these conditions is not necessarily the same as the commercial moisture regain for the fibers.1.4 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 exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.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.

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4.1 This test method is particularly applicable where the fluid has too high a viscosity or where a component is too volatile for a specific gravity balance determination.1.1 This test method covers the measurement of density (weight per gallon) of adhesives, and components thereof, when in liquid form.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 加购物车

5.1 This test method is used to determine the density of construction slurries in the laboratory and field. For freshly mixed slurry, this test method may be used as an indicator of mix proportions. For in-trench slurry or in-borehole slurry, a certain value may be specified for maintaining trench or borehole stability.NOTE 1: The quality of the result produced by this standard depends on the competence of the personnel performing it and the suitability of the equipment and facilities being 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 ensure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.1.1 This test method covers the determination of the density of slurries used in slurry construction techniques, such as those used to drill borings, maintain trench stability, perform ground improvement, and form hydraulic barriers. This test method is modified from API Recommended Practice 13B.1.2 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only and are not considered standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.1.2.1 Note that unitless specific gravity is equivalent to SI density in g/cm3.1.2.2 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This practice implicitly combines two separate systems of units; the absolute and the gravitational systems. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. As stated, this standard includes the gravitational system of inch-pound units and does not use/present the slug unit of mass. However, the use of balances and scales recording pounds of mass (lbm) or recording density in lbm/ft3 shall not be regarded as nonconformance with this standard.1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this test method.1.3.1 For purposes of comparing a measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal of significant digits in the specified limit.1.3.2 The procedures used to specify how data are collected/recorded or calculated in the 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 analysis methods for engineering design.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： 515元 加购物车

5.1 Fiber density is useful in the evaluation of new materials at the research and development level and is one of the material properties normally given in fiber specifications.5.2 Fiber density can be used to determine fiber strength and modulus of a single fiber or bundle of fibers. These properties are based on load or modulus slope over an effective area. Fiber density, when used with the lineal mass of the specimen, can calculate an approximate, total effective area for the specimen.5.3 In composite applications, fiber density is used as constituent property when determining reinforcement volume and void volume based on reinforcement mass and laminate density.1.1 These test methods cover two procedures for determination of the density of flax fiber and are applicable to fibers of any length.1.1.1 Test Method A—Gas Pycnometry—This is the more accurate method of density measurement and is preferred in cases in which specimen conditioning (oven drying) can be applied or outgassing effects can be mitigated by purge settings. The level of accuracy for the test methods can be assessed from the precision and bias tables. Outgassing effects can be assessed by performing a purge cycle, pressurization, and pressure stability check on the sample. If the pressure increases in an isolated sample chamber, outgassing may affect the accuracy of results. Oven dry specimens below 55 ºC to equilibrium with a 0 % relative humidity (RH) environment or use longer purge methods, or both, to eliminate outgassing effects.1.1.2 Test Method B—Buoyancy (Archimedes) Method—This is acceptable as an alternative to Test Method A in applications in which less accurate results are sufficient, as represented in the precision and bias tables. Test Method B is preferred in cases in which outgassing effects in Test Method A cannot be addressed by oven drying or purge settings and prevent Test Method A from producing valid results.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. Specific hazard statements are given in Sections 9 and 17.1.4 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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