定价： 819元 / 折扣价： 697 元

定价： 260元 / 折扣价： 221 元 加购物车

4.1 The degree of deacetylation of chitosan, as well at the molar mass and molar mass distribution, determines the functionality of chitosan in an application. For instance, functional and biological effects are highly dependent upon the composition and molar mass of the polymer.4.2 This test method describes procedures for measurement of molar mass of chitosan chlorides and glutamates, and chitosan base, although it in principle applies to any chitosan salt. The measured molar mass is that for chitosan acetate, since the mobile phase contains acetate as counter ion. This value can further be converted into the corresponding molar mass for the chitosan as a base, or the parent salt form (chloride or glutamate).4.3 Light scattering is one of very few methods available for the determination of absolute molar mass and structure, and it is applicable over the broadest range of molar masses of any method. Combining light scattering detection with size exclusion chromatography (SEC), which sorts molecules according to size, gives the ability to analyze polydisperse samples, as well as obtaining information on branching and molecular conformation. This means that both the number-average and mass-average values for molar mass and size may be obtained for most samples. Furthermore, one has the ability to calculate the distributions of the molar masses and sizes.4.4 Multi-angle laser light scattering (MALS) is a technique where measurements of scattered light are made simultaneously over a range of different angles. MALS detection can be used to obtain information on molecular size, since this parameter is determined by the angular variation of the scattered light. Molar mass may in principle be determined by detecting scattered light at a single low angle (LALLS). However, advantages with MALS as compared to LALLS are: (1) less noise at larger angles, (2) precision of measurements is improved by detecting at several angles, and (3) the ability to detect angular variation allows determination of size, branching, aggregation, and molecular conformation.4.5 Size exclusion chromatography uses columns, which are typically packed with polymer particles containing a network of uniform pores into which solute and solvent molecules can diffuse. While in the pores, molecules are effectively trapped and removed from the flow of the mobile phase. The average residence time in the pores depends upon the size of the solute molecules. Molecules that are larger than the average pore size of the packing are excluded and experience virtually no retention; these are eluted first, in the void volume of the column. Molecules, which may penetrate the pores will have a larger volume available for diffusion, they will be retained in the column for a time dependent upon their molecular size, with smaller molecules eluting after larger molecules.4.6 For polyelectrolytes, dialysis against the elution buffer has been suggested, in order to eliminate Donnan-type artifacts in the molar mass determination by light scattering (1, 2).5 However, in the present method, the size exclusion chromatography step preceding the light scatter detection is an efficient substitute for a dialysis step. The sample is separated on SEC columns with large excess of elution buffer for 30 to 40 min, and it is therefore in full equilibrium with the elution buffer when it reaches the MALS detector.1.1 This test method covers the determination of the molar mass of chitosan and chitosan salts intended for use in biomedical and pharmaceutical applications as well as in tissue engineered medical products (TEMPs) by size exclusion chromatography with multi-angle laser light scattering detection (SEC-MALS). A guide for the characterization of chitosan salts has been published as Guide F2103.1.2 Chitosan and chitosan salts used in TEMPs should be well characterized, including the molar mass and polydispersity (molar mass distribution) in order to ensure uniformity and correct functionality in the final product. This test method will assist end users in choosing the correct chitosan for their particular application. Chitosan may have utility as a scaffold or matrix material for TEMPs, in cell and tissue encapsulation applications, and in drug delivery formulations.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.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 The composition and sequential structure of alginate, as well as the molar mass and molar mass distribution, determines the functionality of alginate in an application. For instance, the gelling properties of an alginate are highly dependent upon the composition and molar mass of the polymer.4.2 Light scattering is one of very few methods available for the determination of absolute molar mass and structure, and it is applicable over the broadest range of molar masses of any method. Combining light scattering detection with size exclusion chromatography (SEC), which sorts molecules according to size, gives the ability to analyze polydisperse samples, as well as to obtain information on branching and molecular conformation. This means that both the number-average and mass-average values for molar mass and size may be obtained for most samples. Furthermore, one has the ability to calculate the distributions of the molar masses and sizes.4.3 Multi-angle laser light scattering (MALS) is a technique where measurements are made simultaneously over a range of different angles and used to determine the scattering at 0°, which directly relates to molecular weight. MALS detection can be used to obtain information on molecular size, since this parameter is determined by the angular variation of the scattered light. This can be related to branching, aggregation, and molecular conformation. Molar mass can also be determined by detecting scattered light at a single low angle (LALS) and assuming that this is not significantly different from the scattering at 0°.4.4 Size exclusion chromatography uses columns, which are typically packed with polymer particles containing a network of uniform pores into which solute and solvent molecules can diffuse. While in the pores, molecules are effectively trapped and removed from the flow of the mobile phase. The average residence time in the pores depends upon the size of the solute molecules. Molecules that are larger than the average pore size of the packing are excluded and experience virtually no retention; these are eluted first, in the void volume of the column. Molecules which penetrate the pores will have a larger volume available for diffusion; their retention will depend on their molecular size, with the smaller molecules eluting last.4.5 For polyelectrolytes, dialysis against the elution buffer has been suggested, in order to eliminate Donnan-type artifacts in the molar mass determination by light scattering (1, 2).6 However, in the present method, the size exclusion chromatography step preceding the light scatter detection is an efficient substitute for a dialysis step. The sample is separated on SEC columns with large excess of elution buffer for 30 to 40 min, and it is therefore in full equilibrium with the elution buffer when it reaches the MALS detector.1.1 This test method covers the determination of the molar mass (typically expressed as grams/mole) of sodium alginate intended for use in biomedical and pharmaceutical applications as well as in tissue-engineered medical products (TEMPs) by size exclusion chromatography with multi-angle laser light scattering detection (SEC-MALS). A guide for the characterization of alginate has been published as Guide F2064.1.2 Alginate used in TEMPs should be well characterized, including the molar mass and polydispersity (molar mass distribution) in order to ensure uniformity and correct functionality in the final product. This test method will assist end users in choosing the correct alginate for their particular application. Alginate may have utility as a scaffold or matrix material for TEMPs, in cell and tissue encapsulation applications, and in drug delivery formulations.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 and health practices and determine the applicability of regulatory limitations prior to use.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 SGCs are used to produce asphalt mixture specimens in the laboratory to assess volumetric properties and predict pavement performance. In the fabrication of an SGC specimen in accordance with Test Method D6925, loose asphalt mixture is placed inside a metal mold, which is then placed into an SGC. A constant consolidation pressure is applied to the sample while the mold gyrates at a nominally constant angle (referred to as the internal angle of gyration) and rate. Consistency in the density of the asphalt specimens produced as measured by Test Method D2726/D2726M or D6752/D6752M is very important to the validity of the tests performed. Specimens of a consistent density are produced when an SGC maintains a constant pressure and a known constant internal angle of gyration during the compaction process.5.2 There are several manufacturers and models of SGC. Each model employs a unique method of setting, inducing, and maintaining the internal angle of gyration. Each model also employs a unique calibration system to measure the external angle of gyration. These existing calibration systems cannot be used universally on all of the different SGC models commercially available. Inconsistencies in asphalt specimens produced on different SGC models have been at least partially attributed to variations in the angle of gyration.5.3 This method describes instruments and processes that can be used to independently measure the internal angle of gyration of any manufacturer’s SGC model under simulated loading conditions. The external shape of the instrument chassis ensures that the points of physical contact between the mold end plates and the instrument occur at a fixed and known distance away from the axis of gyration. As a result, the vertical load is applied at these fixed points, creating tilting moments at each end of the mold.5.4 Unless otherwise specified, a tilting moment of 466.5 N-m shall be applied to the SGC by the instrument while making this measurement.NOTE 1: The quality of the results produced by this test method 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 test method 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.NOTE 2: A 466.5 N-m tilting moment corresponds to a 22 mm eccentric on the AFLS1 or a 21° cone angle on the DAVII-HMS with an applied load of 10603 N (600 kPa at a 150 mm diameter specimen setting).1.1 This test method covers the procedure for the measurement of the Superpave Gyratory Compactor (SGC) internal angle of gyration using an instrument capable of simulating loading conditions similar to those created by an asphalt mixture specimen.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. The value given in rotations per minute is provided for information regarding commonly used units.1.2.1 IEEE/ASTM SI 10, American National Standard for Metric Practice, offers guidance where use of decimal degrees for plane angles (versus radians) and revolutions per minute for rate of gyration (versus radians per second) is acceptable within the IEEE/ASTM SI 10 system when used on a minimal basis.1.3 The text of this test method 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 standard1.4 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 Particle size, shape, and bulk density will affect the flowability of powder material. This test method is used for the determination of the angle of repose of free-flowing mold powders. At angles greater than this value this material will flow.1.2 The values stated in inch-pound units and degrees are to be regarded as standard. The values stated in parentheses are for information only.1.3This 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.

定价： 0元 / 折扣价： 0 元

5.1 The purpose of this practice is to provide a procedure for locating, detecting and estimating the relevance of longitudinally oriented crack-like discontinuities which have been previously indicated by AE examination.5.2 This practice may be used for a pressure vessel that is situated in such a way as to limit access to the vessel's wall. Typical examples include tube trailers and gas tube railroad cars. Since the pressure vessels are stacked horizontally in a frame, with limited space between them, the circumferential location of a discontinuity may be a distance away from the search unit (several skip distances).5.3 This practice has been shown to be effective for cylinders between 9 in. (229 mm) and 24 in. (610 mm) in diameter and wall thicknesses between 1/4 in. (6.4 mm) to 1 in. (26 mm) with discontinuities that are oriented longitudinally in pressure vessel sidewall.5.4 To reliably detect discontinuities by the procedure in this practice, a significant part of the reflecting surface must be transverse to the beam direction.5.5 Evaluation of possible discontinuity in the end faces indicated by AE is not covered by this practice.1.1 This practice describes a contact angle-beam shear wave ultrasonic technique to detect and locate the circumferential position of longitudinally oriented discontinuities and to compare the amplitude of the indication from such discontinuities to that of a specified reference notch. This practice does not address examination of the vessel ends. The basic principles of contact angle-beam examination can be found in Practice E587. Application to pipe and tubing, including the use of notches for standardization, is described in Practice E213.1.2 This practice is appropriate for the ultrasonic examination of cylindrical sections of gas-filled, seamless, steel pressure vessels such as those used for the storage and transportation of pressurized gasses. It is applicable to both isolated vessels and those in assemblies.1.3 The practice is intended to be used following an Acoustic Emission (AE) examination of stacked seamless gaseous pressure vessels (with limited surface scanning area) described in Test Method E1419.1.4 This practice does not establish acceptance criteria. These are determined by the reference notch dimensions, which must be specified by the using parties.NOTE 1: Background information relating to the technical requirements of this practice can be found in the references sited in Test Method E1419, Appendix X1.1.5 Dimensional values stated in inch-pound units are regarded as standard; SI equivalents, in parentheses may be approximate.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

5.1 Measurements made by this test method are related to the night time brightness of retroreflective traffic signs approximately facing the driver of a mid-sized automobile equipped with tungsten filament headlights at about 100 m distance.5.2 Retroreflective material used on traffic signs degrades with time and requires periodic measurement to ensure that the performance of the retroflection provides adequate safety to the driver.5.3 The quality of the sign as to material used, age, and wear pattern will have an effect on the coefficient of retroreflection. These conditions need to be observed and noted by the user.5.4 This test method is not intended for use for the measurement of signs when the instrument entrance and observation angles differ from those specified herein.1.1 This test method covers measurement of the retroreflective properties of sign materials such as traffic signs and symbols (vertical surfaces) using a portable retroreflectometer that can be used in the field. The portable retroreflectometer is a hand-held instrument with a defined standard geometry that can be placed in contact with sign material to measure the retroreflection in a standard geometry. The measurements can be compared to minimum requirements to determine the need for replacement. Entrance and observation angles specified in this test method are those used currently in the United States and may differ from the angles used elsewhere in the world.1.2 This test method is intended to be used for the field measurement of traffic signs but may be used to measure the performance of materials before placing the sign in the field or before placing the sign material on the sign face.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.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 Measurements made by this test method are related to the night time brightness of retroreflective traffic signs approximately facing the driver of a mid-sized automobile equipped with tungsten filament headlights at about 200 m distance.5.2 Retroreflective material used on traffic signs degrades with time and requires periodic measurement to ensure that the performance of the retroflection provides adequate safety to the driver.5.3 The quality of the sign as to material used, age, and wear pattern will have an effect on the coefficient of retroreflection. These conditions need to be observed and noted by the user.5.4 This test method is not intended for use for the measurement of signs when the instrument entrance and observation angles differ from those specified herein.1.1 This test method covers measurement of the retroreflective properties of sign materials such as traffic signs and symbols (vertical surfaces) using a portable retroreflectometer that can be used in the field. The portable retroreflectometer is a hand-held instrument with a defined standard geometry that can be placed in contact with sign material to measure the retroreflection in a standard geometry. The measurements can be compared to minimum requirements to determine the need for replacement. Entrance and observation angles specified in this test method are those used currently in the United States and may differ from the angles used elsewhere in the world.1.2 This test method is intended to be used for the field measurement of traffic signs but may be used to measure the performance of materials before placing the sign in the field or before placing the sign material on the sign face.1.3 This test method covers measurements at a 0.2 degree observation angle. See Test Method E2540 for measurements at a 0.5 degree observation angle.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

5.1 This test method is a tool for quality assurance use. Given a pressure-sensitive label stock and a requirement in terms of the minimum or maximum peel adhesion value expected for this label stock, the data from the test can be used in conjunction with acceptance criteria.5.2 This test method can show the relative bond strength of a given label stock to one or more surfaces of varied material and texture as compared to the standard stainless steel panel. Substitution of panels representative of the proposed substrates for the standard stainless steel panel would be acceptable for this procedure.1.1 This test method covers the measurement of the peel adhesion of pressure-sensitive label stocks. This test method gives a measure of the adherence to a standard steel substrate or to other surfaces of interest for a pressure-sensitive label stock.1.2 This test method provides a means of assessing the uniformity of the adhesion of a given type of pressure-sensitive label stock. The assessment may be within a sheet or roll, between sheets or rolls, or between production lots.1.3 Variations in the label stock facestock and adhesive can affect the response; therefore, this test method cannot be used to pinpoint the specific cause(s) of nonuniformity.1.4 This test method may not be appropriate to test label stocks having either stiff backings or backings showing a high stretch at low forces. These characteristics could result in a high variability of the test response, which is not a true indication of the real nature of the adhesive bond.1.5 The values stated in either SI or inch-pound units are to be regarded separately as the standard. The values stated in each system may not be exact equivalents; therefore, each system must be used independently, without combining values in any way.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

This specification covers the material and fabrication of new reusable, slotted angle metal crates intended for use as containers for domestic and overseas shipment of lightweight airframe components and lightweight bulky items for domestic or overseas air and surface shipments. This specification includes metal crates in a variety of types, classes, and styles reflecting varied performance, but does not address their performance under al atmosphere, handling, shipping, and storage conditions. Type I are open crates, while Type II are fully-enclosed or sheathed with solid material. On the other hand, Class 1 are used for outside or indeterminate storage, while Class 2 are for inside or protected storage. And finally, Style A are furnished without skids or rubbing strips, while Style B are furnished with skid blocks or skids with rubbing strips and provisions for forklift truck handling. Details regarding the manufacture and construction requirements are itemized thoroughly.1.1 This specification covers the material and fabrication of new reusable metal (slotted angle) crates intended for use as containers for domestic and overseas shipment of lightweight airframe components and lightweight bulky items, not exceeding 3000 lb [1361 kg] for domestic or overseas air and surface shipments.1.2 Slotted angle crate performance is dependent on its fabricated components; therefore, a variety of types, classes, and styles reflecting varied performance are specified. This specification, however, does not cover slotted angle crate performance under all atmosphere, handling, shipping, and storage conditions.1.3 If the use of other construction methods or techniques are acceptable and permitted (see 5.1.12), the resulting packaging systems shall be of equal or better performance than would result from the use of these specified materials and procedures. The appropriate distribution cycle specified in Practice D4169 can be used to develop comparative procedures and criteria.1.4 The values stated in either inch-pound or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. See IEEE/ASTM SI 10 for conversion of units.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： 646元 / 折扣价： 550 元 加购物车

4.1 Some tile surfaces may exhibit variations under low angle conditions as part of the designed aesthetic.4.2 This practice is intended for tiles that are designed to have an overall uniform appearance under low angle conditions.1.1 This practice replicates low angle viewing conditions on ceramic tile installations.1.2 The values stated in inch-pound units are to be regarded as the standard. The values in parentheses are for information only.1.3 This qualitative practice is intended to provide general guidance at the manufacturing level to determine if product will be acceptable under typical end use conditions.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 / 折扣价： 438 元 加购物车

5.1 This test method is designed to show the adhesion of a pressure-sensitive tape to fiberboard when the tape is under a constant stress. Test data from this test method for some types of packaging tape relates to tape performance on fiberboard box closure.5.2 Procedure A should be used when comparing tapes to an established requirement. The requirement may be established using either the standard linerboard or another linerboard representing a specific fiberboard.5.3 Procedure B should be used to rank tapes as to their ability to adhere to fiberboard.1.1 This test method covers the determination of the property of adhesion of pressure-sensitive tape to a fiber-board surface. The user of this test method has the option of choosing the paper surface for the test. The test surface may be the standard linerboard, another linerboard (or paper) of individual interest, or a specific fiberboard.1.2 The values stated in either SI or inch-pound units are to be regarded separately as standard. The values stated in each system are not exact equivalents; therefore, each system must be used independently, without combining values in any way.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

5.1 This standard is useful for characterizing the wettability of surfaces. A surface that is easy to wet is one over which a coating is more likely to give good adhesion and appearance and less likely to suffer surface tension related defects such as crawling, cratering, pinholing and orange peel.5.2 This standard also can be used to test pigment surfaces for wettability, particularly by potential surfactant- or resin-based dispersants or mill bases. Easily wetted pigments are more likely to be easy to disperse and dispersants/mill bases that wet pigments of interest are more likely to disperse those pigments well.5.3 Although the contact angle is governed by the surface tensions of the test liquid and test surface, the angle cannot provide a surface tension value directly.5.4 A low advancing contact angle value (<45°) is indicative of wetting and angles of 10 to 20° are indicative of excellent wetting.5.5 Water can be used as a test liquid to establish (via the advancing contact angle) whether a surface is hydrophilic (angle <45°), hydrophobic (angle >90°) or somewhere in-between (angle of 45 to 90°). Water contact angles have been used to estimate surface cleanliness before and after cleaning operations, ease of wettability of surfaces by waterborne coatings and the effectiveness of rinsing processes.5.6 An organic liquid such as a solvent also can be used to characterize a substrate, coating or pigment. The resultant contact angle will depend on the surface tensions of the liquid and the test surface. A low surface tension (energy) test surface will not be wet by a high surface tension liquid.5.7 In addition to water and solvents, a surfactant dispersion or dispersant solution can be used to test a pigment surface. Any test liquid that is a potential dispersant for a test pigment must wet the pigment well or it will not work as a dispersant.5.8 Contact angle measurements can be used to map surfaces in terms of hydrophilicity, presence of low surface tension components or contaminants, or variations in composition. Other analytical methods such as infrared microscopy would be needed to identify the chemical moieties that give the contact angle differences.5.9 This test method can be used on nearly all coatings and substrates and may be extended to pigments by compressing the pigment powder into a solid disk.1.1 This practice covers the measurement of the angle of contact when a drop of liquid is applied to a coated surface, substrate, or preformed disk of pigment.1.2 There are two types of contact angles, advancing and receding. This standard deals only with advancing contact angles.1.3 This practice is intended to supplement the manufacturer’s instructions for the device being used to make the measurements, but is not intended to replace them.1.4 A common test liquid is water, but many other liquids such as solvents, surfactant and dispersant solutions and even liquid paints can be used.1.5 This practice is based on goniometry, which involves the observation of a sessile drop of test liquid on a solid substrate.1.6 Although contact angles are governed by surface tension, this standard cannot be used to measure surface tension directly.1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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： 515元 / 折扣价： 438 元 加购物车

4.1 The rectangular or square copper alloy tube covered by this test method may be used in applications in which control of twist is important to proper fit in final assembly and to minimize rework to bring the tube into compliance. It is recognized that the amount of twist, in degrees per increment of length, can change as a result of the weight of the product and its length during measurement.4.2 This test method provides a procedure for measuring the twist in square and rectangular copper and copper alloy tubes as a measure of the deviation from straightness.4.3 This test method allows the purchaser and supplier or manufacturer to inspect square and rectangular copper and copper alloy tube with a standard technique that provides acceptable twist in delivered tubes.1.1 This test method establishes the requirements for the determination of the angle of twist in rectangular and square copper and copper alloy tube.1.2 The values stated in inch-pound 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 / 折扣价： 438 元 加购物车