定价： 515元 加购物车

定价： 590元 加购物车

定价： 515元 加购物车

3.1 A diffusion coating is one produced by causing an element or elements to react with or diffuse into, or both, the surface of a metallic substrate, thus chemically altering the substrate adjacent to the surface. To appreciate the significance of coating thickness measurements one must understand the contributions to a particular coating of solid-solution zones in the substrate and reaction products such as intermetallic compounds.1.1 These test methods cover two procedures for measuring the thickness of diffusion coatings.1.2 Test Method A is the determination of the dimensional-change thickness, defined as the difference in the thickness of the part before and after coating. (The terms micrometer thickness and part growth are considered synonymous with dimensional change thickness.)1.3 Test Method B is the determination of total coating thickness, defined as the distance between the observably unaffected substrate and the exterior surface of the coating. This includes the total of all included phases, zones and layers. (The term case depth is considered to be synonymous with total coating thickness.) The total coating thickness is determined by cross-sectioning the coating, preparing a metallurgical mount and microscopically measuring the coating thickness.1.4 The total coating thickness as determined microscopically from a cross-section will usually be greater than, or equal to, the dimensional change thickness determined by part growth. When the coating is produced primarily by reaction with the substrate, the substrate-coating interface recedes as the substrate is consumed in the reaction. In such cases the difference between the total coating thickness and the dimensional change thickness is the thickness of the substrate consumed.1.5 Diffusion coatings are usually formed at elevated temperatures for service at elevated temperatures. This means that diffusion coatings are dynamic systems which are continually undergoing changes while in an elevated-temperature environment. It is necessary to know that certain phases are growing at the expense of others and to know the previous history of a coating to understand the significance of coating thickness data.1.6 Values in SI units are to be regarded as the standard. Inch-pound units are provided for information only.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 加购物车

5.1 This practice is used to determine the thickness and lateral extent of a peat deposit such that, the volume of the peat deposit can be calculated. When the overlying material is peat and the underlying one is soil or bedrock, the depth of change may be interpreted as the thickness of peat.5.2 This information is useful to peat producers to evaluate the volume of the deposit for planning purposes. It is also useful to peat producers and regulators in evaluating some ecologic functions.NOTE 1: 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.1.1 This practice uses a technique of probing to estimate the thickness of surficial peat deposits overlying mineral soil or bedrock.1.1.1 The resistance to penetration of a pushed or driven rod will increase sharply at the boundary of a peat layer with underlying mineral soil or bedrock. When this abrupt change is measured in a series of probings with an appropriate spacing, the thickness and areal extent of peat can be defined and the volume of peat may be calculated.1.2 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.1.3 All measured and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.3.1 The procedures used to specify how data are collected/recorded and 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 these test methods to consider significant digits used in analysis methods for engineering data.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 practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.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

定价： 590元 加购物车

5.1 Many coating properties are markedly affected by the film thickness of the dry film such as adhesion, flexibility, wear, durability, chemical resistance, and hardness. To be able to compare results obtained by different operators, it is essential to measure film thickness carefully.5.2 Most protective and high performance coatings are applied to meet a requirement or a specification for the dry-film thickness of each coat, or for the complete system, or both. Coatings must be applied within certain minimum and maximum thickness tolerances in order that they can fulfill their intended function. In addition to potential performance deficiencies, it is uneconomical to apply more material than necessary when coating large areas such as floors and walls.5.3 Low readings may occur occasionally on coatings with rough surfaces. The instrument may allow a user adjustment to prevent this.5.4 This test method may not be applicable to measure organic coating thickness on all substrates. The instrument's ability to detect a distinct interface between the coating and the substrate may be impeded if the coating and the substrate are of similar composition, density or attenuation or if the coating is non-homogeneous. Verify operation on a known thickness of the coating/substrate combination if these circumstances are thought to exist.5.5 Multilayered coatings have many interfaces and the instrument will measure to the interface separating the two most acoustically different materials. Some instruments have the ability to detect and measure the individual layer thicknesses in a multi-layer system.5.6 The use of this test method is not necessarily limited by the type of substrate material.1.1 This test method describes the use of ultrasonic film thickness gages to measure accurately and nondestructively the dry film thickness of organic coatings applied over a substrate of dissimilar material. Measurements may be made on field structures, on commercially manufactured products, or on laboratory test specimens. These types of gages can accurately measure the dry film thickness of organic coatings on a variety of substrates such as concrete, wood, wallboard, plastic, fiber composites and metal.1.2 This test method is not applicable to coatings that will be readily deformable under load of the measuring instrument as the instrument probe is placed directly on the coating surface to take a reading.1.3 The effective range of instruments using the principle of ultrasonics is limited by gage design. A thickness range of 8 μm to 7.60 mm (0.3 to 300 mils) has been demonstrated.1.4 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 加购物车

5.1 Normally, a close tolerance is desirable for core thickness so that sandwich panels may be manufactured with all the sandwich components fitting properly and without crushing the core.5.2 These test methods are designed for measuring thickness of core as it is produced and are not intended for use in determining dimensions of core specimens for other tests.5.3 These test methods provide standard methods of obtaining the core thickness of flat sandwich core materials, and provide a basis for determining average thickness dimensions. The thickness properties derived may be used in design properties, material specifications, research and development applications, and quality assurance.5.4 Factors that influence core thickness measurement and shall therefore be reported include the following: core material through-thickness rigidity, surface roughness, specimen geometry (including warpage), specimen preparation, methods of dimensional measurement, specimen conditioning, and moisture content during dimensional measurements.1.1 These test methods cover plant manufacturing procedures for measuring the thickness of flat sandwich cores. 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). The two test methods covered include the following:1.1.1 Test Method A—Roller-Type Thickness Tester.1.1.2 Test Method B—Disk-Type Thickness Tester.NOTE 1: These test methods are designed for measuring thickness of core as it is produced and are not intended for use in determining dimensions of core specimens for other tests.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.

定价： 590元 加购物车

5.1 Some electrical properties, such as dielectric strength, vary with the thickness of the material. Determination of certain properties, such as relative permittivity (dielectric constant) and volume resistivity, usually require a knowledge of the thickness. Design and construction of electrical machinery require that the thickness of insulation be known.1.1 These test methods cover the determination of the thickness of several types of solid electrical insulating materials employing recommended techniques. Use these test methods except as otherwise required by a material specification.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 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 加购物车

5.1 Thickness is one of the basic physical properties used to control the quality of many geosynthetics. Thickness values can be required for calculation of some geosynthetics properties such as permeability and tensile stress, among others.5.2 The thickness of some geosynthetics may vary considerably with the applied normal load. Specific pressures and surfaces on which they are applied are indicated in this method to ensure all results are comparable.5.3 This test method may be used for acceptance testing of commercial shipments of geosynthetics for which this method is applicable (see 1.1).NOTE 1: The user should be aware that the compressibility of some materials, their rebound characteristics, and other phenomenon will affect the thickness of some geosynthetics, following the time when they are rolled up, shipped, and stored.1.1 This test method covers the measurement of the nominal thickness of geosynthetics, except textured and some structured geomembranes where the entire surface of the presser foot cannot come into complete contact with the geosynthetic surface.1.2 This test method does not provide thickness values for geosynthetics under variable normal compressive stresses. This test method determines nominal thickness, not necessarily minimum thickness.1.3 The values stated in SI units are to be regarded as 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.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

定价： 515元 加购物车

定价： 515元 加购物车

定价： 646元 加购物车

定价： 712元 加购物车

定价： 571元 加购物车