This specification covers steel joint bars of low-carbon, medium-carbon, and high-carbon grades (Grades 1, 2, and 3) for railway applications. Steel shall be made through basic-oxygen or electric-furnace processes and cast through continuous process or in ingots. An analysis of each heat or cast shall be made to determine the percentage compositions of carbon, manganese, phosphorus, and sulfur. Tension test shall also be made to conform to specified tensile strength and elongation values. Guidelines on the dimensions and physical variations of joint bars are given. Inspection, rejection, rehearing, certification, and product marking procedures are cited.1.1 This specification covers steel joint bars for connecting steel rails in mine, industrial, and standard railroad track.1.2 Three grades of joint bars are defined for applications where non-heat treated bars are suitable:1.2.1 Grade 1, low-carbon, primarily for industrial and mine use.1.2.2 Grade 2, medium-carbon, primarily for industrial and mine use.1.2.3 Grade 3, high-carbon, for general use in standard railroad track. They may be used in the production of insulated track joints.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 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 Comparison of brake horsepower developed and of specific fuel consumption rates from engine to engine may be made by use of data based upon a standard for composition of an engine assembly.4.2 The purchaser of the engine assembly will be fully advised of the minimum scope of assembly which the purchaser may rightfully expect to be encompassed by a response to a request for quotation and to be delivered in response to a purchase order unless the engine builder in the proposal or in the offer to sell has clearly advised otherwise.4.3 It will be made apparent to the purchaser that additional auxiliary and accessory equipment will be needed to supplement the defined engine assembly when full consideration is given to the application of the engine assembly as a prime mover in a specific vessel.1.1 This guide covers performance and minimum scope of assembly of all medium speed marine diesel engines intended for main propulsion of single or multiple screw propelled marine vessels or for vessels using other than screw propeller-type main propulsion.1.2 This guide is intended to supplement the regulations of legally constituted regulating authorities. In the event of any conflict, which may become apparent after publication of this guide, with such legally constituted regulations, the latter shall take precedence, as may be applicable within the jurisdiction of such authorities and specific to each case, unless such latter regulations are formally waived by proper cognizant authority.1.3 This guide is not intended to relieve the purchaser of the obligation fully to advise the engine builder of all of the purchaser’s unique operational considerations to allow those considerations to be satisfied.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

4.1 These test methods for the chemical analysis of metals and alloys are primarily intended as referee methods to test such materials for compliance with compositional specifications particularly those under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel, and Related Alloys. It is assumed that all who use these test methods will be trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory under appropriate quality control practices such as those described in Guide E882.1.1 These test methods cover the chemical analysis of tool steels and other similar medium- and high-alloy steels having chemical compositions within the following limits:Element Composition Range, %Aluminum   0.005 to 1.5Boron   0.001 to 0.10Carbon   0.03  to 2.50Chromium   0.10  to 14.0Cobalt   0.10  to 14.0Copper   0.01  to 2.0Lead   0.001 to 0.01Manganese   0.10  to 15.00Molybdenum   0.01  to 10.00Nickel   0.02  to 4.00Nitrogen   0.001 to 0.20Phosphorus   0.002 to 0.05Silicon   0.10  to 2.50Sulfur   0.002 to 0.40Tungsten   0.01  to 21.00Vanadium   0.02  to 5.501.2 The test methods in this standard are contained in the sections indicated below:    SectionsCarbon, Total, by the Combustion— Thermal Conductivity Method— Discontinued 1986   125–135Carbon, Total, by the Combustion Gravimetric Method—Discontinued 2012   78–88Chromium by the Atomic Absorption Spectrometry Method (0.006 % to 1.00 %) 174–183Chromium by the Peroxydisulfate Oxidation—Titration Method   (0.10 % to 14.00 %) 184–192Chromium by the Peroxydisulfate-Oxidation Titrimetric Method—Discontinued 1980   117–124Cobalt by the Ion-Exchange— Potentiometric Titration Method     (2 % to 14 %)  52–59Cobalt by the Nitroso-R-Salt  Spectrophotometric Method  (0.10 % to 5.0 %)  60–69Copper by the Neocuproine  Spectrophotometric Method  (0.01 % to 2.00 %) 89–98Copper by the Sulfide Precipitation- Electrodeposition Gravimetric Method   (0.01 % to 2.0 %)  70–77Lead by the Ion-Exchange—Atomic  Absorption Spectrometry Method (0.001 % to 0.01 %) 99–108Manganese by the Periodate  Spectrophotometric Method  (0.10 % to 5.00 %) 9–18Molybdenum by the Ion Exchange– 8-Hydroxyquinoline Gravimetric Method    203–210Molybdenum by the Thiocyanate Spectrophotometric Method  (0.01 % to 1.50 %) 162–173Nickel by the Dimethylglyoxime Gravimetric Method (0.1 % to 4.0 %) 144–151Phosphorus by the Alkalimetric Method  (0.01 % to 0.05 %) 136–143Phosphorus by the Molybdenum Blue  Spectrophotometric Method (0.002 % to 0.05 %) 19–29Silicon by the Gravimetric Method  (0.10 % to 2.50 %) 45–51Sulfur by the Gravimetric Method—Discontinued 1988   29–35Sulfur by the Combustion-Iodate  Titration Method—Discontinued 2012   36–44Sulfur by the Chromatographic Gravimetric Method—Discontinued 1980   109–116Tin by the Solvent Extraction— Atomic Absorption Spectrometry Method (0.002 % to 0.10 %) 152–161Vanadium by the Atomic Absorption Spectrometry Method (0.006 % to 0.15 %) 193–2021.3 Test methods for the determination of carbon and sulfur not included in this standard can be found in Test Methods E1019.1.4 Some of the composition ranges given in 1.1 are too broad to be covered by a single test method and therefore this standard contains multiple test methods for some elements. The user must select the proper test method by matching the information given in the and Interference sections of each test method with the composition of the alloy to be analyzed.1.5 The values stated in SI units are to be regarded as 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. Specific hazards statements are given in Section 6 and in special “Warning” paragraphs throughout these test methods.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： 843元 / 折扣价： 717 元 加购物车

3.1 Membrane switch keys are subjected to repeated actuations, usually by a human finger. This can transfer body oil, hand creams, automotive fluids and so forth. Materials are often subjected to other conditions (for example, wiping, cleaning, rubbing) during handling, end-use, shipment, or storage that may cause abrasion damage. The result may be a significant removal of the coatings, text, or decorative inks.3.2 This test method is applicable to a wide range of materials. The main criterion is that the abrasion process produces visible wear or breakthrough of the surface being tested.3.3 The amount of abrasion damage to a surface is dependent on numerous variables. This test method provides a way of comparing relative abrasion resistance and the effect of chemicals on inks, coatings, and substrates. In no way do the results provide a correlation value of the number of human finger touches before coating failure. It only provides a means to compare results of tests performed using the same equipment, abrasive materials and loading conditions.3.4 The test method can be used for quality control purposes, as a research and development tool, to evaluate material combinations for a given application, or for the comparison of materials with relatively similar properties and the effect of chemicals on the abrasion resistance.1.1 This test method describes the procedure for subjecting inks or coatings on substrates to an abrasive medium, with or without the application of chemicals, at a specified force.1.2 Within certain limitations, as described in this standard, this test method is applicable for materials including, but not limited to: printed or coated polyester, polycarbonate, and silicone rubber. The samples can be either flat or contoured.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 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 quantity and quality of the spores produced by this practice may be used to assess environmental surface disinfectants for sporicidal activity (4). The method is applicable to standard as well as clinically isolated toxigenic and non-toxigenic strains of C. difficile.1.1 This practice describes the production and semipurification of C. difficile spores (also called endospores) primarily for use in testing the sporicidal activities of environmental surface disinfectants (Test Methods E2111and E2197); such spores can also be used to study their structure, chemistry and germination.1.2 While the practice described is based on the use of 500-mL volumes of the liquid culture medium in an anaerobic incubator, anaerobic jars with smaller volumes of the same medium can also be used.1.3 It is the responsibility of the investigator to determine whether Good Laboratory Practice (GLP) regulations are required and to follow them when appropriate (40 CFR, Part 160 for EPA submissions and 21 CFR; Part 58 for FDA submissions).1.4 Warning—This standard may involve hazardous materials, chemicals, and microorganisms and should be performed only by persons with formal training in microbiology.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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

This specification covers stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use in insulated conductor assemblies for electrical purposes. These conductors shall be composed of one or more roller shaped or die closed layers of helically laid wires using the single input wire. For stranded conductors, the direction of lay of the outer layer shall be leeft hand and may be reversed or unidirectional/unilay in successive layers. Test for the physical and electrical properties of wires composing conductors made from hard-drawn or medium-hard-drawn wires, uncoated or coated, shall be made before but not after stranding. For the purpose of calculating mass, cross sections, and so forth, the density of the copper shall be taken. The mass and electrical resistance of a unit length of stranded unsealed conductor are a function of the lenght of lay shall be calculated.1.1 This specification covers stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use in insulated conductor assemblies for electrical purposes. These conductors shall be composed of one or more roller shaped or die closed layers of helically laid wires using the single input wire (SIW) methodology. (see Note 1 and Explanatory Note 1)NOTE 1: Sealed conductors which are intended to prevent longitudinal water propagation and are further covered/insulated, are also permitted within the guidelines of this specification.1.2 The values stated in inch-pound or SI units are to be regarded separately as standard. The values 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.1.2.1 For density, resistivity, and temperature, the values stated in SI units are to be regarded as standard.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

This specification deals with continuous grain flow carbon and alloy steel crankshaft forgings intended for medium speed diesel and natural gas engines. The steel used in the manufacture of the forgings is required to be vacuum degassed. Heat treatment, which may be done either before or after rough machining, shall consist of normalizing followed by tempering at a subcritical temperature, or austenitizing, liquid quenching and subcritical tempering. Charpy impact and tensile tests, which shall be performed at a frequency of one test per heat treatment load, shall be used to evaluate tensile strength, yield strength, elongation, reduction of area, and Brinell hardness requirements of forgings. Chemical composition requirements shall also be examined by heat analysis. Grain size tests and non-destructive magnetic particle examinations shall be conducted as well. When required by the purchaser, crankshafts may be surface hardened in designated areas for the purposes of enhanced wear resistance and fatigue strength.1.1 This specification covers continuous grain flow forged carbon and alloy steel crankshafts for medium speed diesel and natural gas engines.1.2 The steel used in the manufacture of the forgings is required to be vacuum degassed.1.3 The choice of steel composition grade for a given strength class is normally made by the forging supplier, unless otherwise specified by the purchaser.1.4 Provision is made for treatment of designated surfaces of the crankshaft to provide enhanced fatigue strength, or wear resistance, or both.1.5 Except as specifically required in this specification, all provisions of Specification A788/A788M apply.1.6 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound units.1.7 The values stated in either inch-pound units or SI (metric) units are to be regarded separately as standard. Within the text and tables the SI units are shown in brackets. 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.1.8 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： 590元 / 折扣价： 502 元 加购物车

This practice covers the procedures used for detection of mycoplasma contamination of cell cultures by growth on agarose medium. This practice does not cover identification of mycoplasma and indirect methods for detection of mycoplasma. This practice will not detect cultivar strains of Mycoplasma hyorhinis nor intended for use in detection of mycoplasma contamination in sera, culture media, vaccines, or other systems. The practice involves DM-1 solid medium preparation, quality control, and mycoplasma isolation.1.1 This practice covers the procedures used for detection of mycoplasma contamination by direct microbiological culture.1.2 This practice does not cover indirect methods for detection of mycoplasma such as DNA staining, biochemical detection, or genetic probes.1.3 This practice does not cover methods for identification of mycoplasma organisms.1.4 This practice will not detect cultivar strains (1) of Mycoplasma hyorhinis.1.5 This practice is not intended for use in detection of mycoplasma contamination in sera, culture media, vaccines, or other systems.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： 0元 / 折扣价： 0 元

5.1 This plate format is useful for the routine monitoring of culturable, waterborne bacteria in potable and non-potable waters. The significance of finding these bacteria can help with identifying water quality or water system problems or evaluate compliance with maintenance protocols. This test method uses small volumes of water, or dilutions thereof, and provides an easy and reliable method that eliminates media preparation and reduces laboratory waste.1.1 This test method describes a simple procedure for the quantification of culturable, waterborne bacteria in potable water (drinking water, bottled water, and dental water, for example) and non-potable waters (cooling towers, for example).1.1.1 The EasyDisc2, 3 plate format is designed to test 1 mL of a water sample on a 47 mm gridded plate containing a growth reagent embedded to the plate’s inner surface.1.1.2 Detection is based on colorimetric technology in which viable, aerobic, heterotrophic, waterborne bacteria grow when present in the water sample, displaying a color reaction which allows for a simplified visualization of colony growth.1.2 Each plate can accurately detect up to 300 colony forming units per 1 mL (CFU/1 mL) of sample. To increase the quantification range, a sample dilution can be used. Adjust the CFU/mL result to reflect dilutions.1.3 This test method can be used for potable (for example, drinking, bottled, and dental) waters and non-potable waters such as cooling tower waters. It is the user’s responsibility to adhere to all requirements by local regulations and ensure the validity of this test method for waters other than those tested as part of the Interlaboratory Study (ILS).1.4 The values stated in SI units are to be regarded as the 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 / 折扣价： 502 元 加购物车

4.1 Static measurements of tires are important to tire manufacturers, processing engineers, and vehicle design engineers for purposes of commerce (in consumer/vendor agreements) and in tire research and development.4.2 The procedures are sufficiently detailed to achieve commercially acceptable reproducibility among laboratories and may therefore be used for specification, compliance, or reference purposes.4.3 Changes attributable to growth after inflation may be obtained by comparing measurements made immediately after inflation with those made 18 to 24 h later.1.1 This test method covers methods for performing certain mechanical static measurements on tires. The term “static” implies that the tire is not rotating while measurements are being made.1.2 The values stated in SI units are to be regarded as 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： 590元 / 折扣价： 502 元 加购物车

This specification covers unpigmented, unsupported, sheet or tubular, medium-density polyethylene films intended for general uses and packaging applications. The film shall be made from homopolymer polyethylene, copolymer polyethylene commonly referred to as low-pressure polyethylene, or blends of homopolymers and copolymers that include ethylene/vinyl-acetate copolymers. The specimens shall be conditioned before testing in the standard laboratory temperature. Tests shall be conducted to determine the physical properties of the specimens which shall conform to the following physical requirements: secant modulus or stiffness; kinetic coefficient of friction; optical properties such as clarity, gloss, and haze; surface treatment level or wetting tension; impact resistance; tensile strength and elongation at break; heat sealability; and odor level.1.1 This specification covers unpigmented, unsupported, sheet or tubular, medium-density polyethylene films (hereafter referred to as film or films) from resins having densities in the range from 926.0 to 938.0 kg/m3 (0.926 to 0.938 g/cm3), inclusive, as measured on molded plaques.1.2 This specification is applicable to homopolymer polyethylene but is not restricted to it.1.3 This specification is also applicable to films made from copolymer polyethylene commonly referred to in industry as low-pressure polyethylene.1.4 This specification is also applicable to films made from blends of homopolymers and copolymers, including ethylene/vinyl-acetate copolymers.1.5 This specification allows for the use of recycled polyethylene film or resin as feedstock, in whole or in part, as long as all the requirements of this specification are met and as long as any specific requirements as governed by the producer and end user are also met (see Note 1).NOTE 1: Guide D7209 contains terminology and definitions relating to recycled plastics.1.6 Special care must be exercised if this specification is applied to colored or pigmented films. This specification does not address specific problems associated with coloring, such as, quantity and quality of pigment dispersion, optical properties, and increase in density. These and other areas must be taken into account by mutual agreement between the supplier and the purchaser.1.7 The thickness of the films covered by this specification range from 25 to 100 μm (0.001 to 0.004 in.), inclusive. The maximum width of the sheet or lay-flat is 3.05 m (120 in.).1.8 This specification does not cover oriented heat-shrinkable films.1.9 This specification defines the levels of various physical properties from which specifications for specific films are to be described. The levels of physical properties required by a film for a given application are selected from Section 6 and the corresponding tables. However, Sections 7.2 – 7.5 relating to tolerances shall apply without change to all film falling within the scope indicated by the title and 1.1 – 1.4.1.10 This specification covers dimensional tolerances, classification, intrinsic quality requirements, and test methods. The dimensional tolerances include thickness, width, and length or yield. Classification defines types, classes, surfaces, and finishes. The intrinsic quality requirements include density, workmanship, impact strength, tensile strength, heat sealability, and odor, as well as the classification properties for stiffness, coefficient of friction, optical properties, and surface treatment. A sampling method is included.1.11 The values stated in SI units are to be regarded as standard. The values in parentheses are given for information only.1.12 The following precautionary caveat pertains only to the test methods portion, Section 10, of this specification: 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.NOTE 2: There is no known ISO equivalent to this standard.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 The transmittance of an attenuating medium can cause errors for an infrared thermographer using an infrared imaging radiometer to measure the temperature of a specimen through the medium. Three test methods are given for measuring and compensating for this error source.5.1.1 A procedure is given for measuring the transmittance of an attenuating medium.5.1.2 A procedure is given for compensating for errors when measuring the temperature of a specimen having a known emissivity through an attenuating medium with a known transmittance.5.1.3 A procedure is given for measuring and compensating for transmittance and emissivity errors when the specimen temperature is known.5.2 These procedures can be used in the field or laboratory using commonly available materials.5.3 These procedures can be used with any infrared radiometers that have the required computer capabilities.5.4 The values of transmittance are defined only in terms of the procedure for the purpose of process control and nondestructive evaluation of materials.1.1 This practice covers procedures for measuring and compensating for transmittance when using an infrared imaging radiometer to measure the temperature of a specimen through an attenuating medium, such as a window, filter, or atmosphere.21.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 These procedures may involve use of equipment and materials in the presence of heated or electrically-energized equipment, or both.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

1.1 This test method covers the determination of capillary-moisture relationships for coarse- and medium-textured soils as indicated by the soil-moisture tension relations for tensions between 10 and 101 kPa (0.1 and 1 atm). Under equilibrium conditions, moisture tension is defined as the equivalent negative gage pressure, or suction, corresponding to a soil moisture content. This test method determines the equilibrium moisture content retained in a soil subjected to a given soil-water tension. This test method is not suitable for very fine-textured soils.Note 1--For determination of capillary-moisture relationships for fine-textured soils, refer to Test Method D3152.1.2 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： 0元 / 折扣价： 0 元

5.1 When significant quantities of inorganic or organic material are present in water samples (high suspended solids), microplastic particles/fibers can be masked and the ability to conduct reliable identification and quantification analyses of the plastic particles/fibers can be impeded.5.2 In order to quantify the occurrence of microplastic particles/fibers in wastewater influent (high suspended solids), the sampling procedure must be able to reliably collect samples at a constant flow over the desired 24-hour interval to reflect changes in diurnal flow. For wastewater influent the capture flow rate should be no less than 1 GPM over the 24-hour interval (approximately 1440 gal or 5450 L total) to minimize the problem with heterogeneity of the suspended solids and to reduce the standard error (the larger the sample size, the smaller the standard error).5.3 In order to quantify the occurrence of microplastic particles/fibers in all other water samples with a lower content of inorganic or organic material present addressed by this practice (low to medium suspended solids), a minimum volume of 1500 L (approximately 400 gal) should be filtered through the appropriate filters or sieves to minimize potential issues with heterogeneity of suspended solids and to reduce the standard error (the larger the sample size, the smaller the standard error).5.4 Microplastic particles/fibers retained on the sieves are suitable for characterization in terms of size, shape, quantity, and composition (polymer type), dependent upon the chosen analytical method.1.1 This practice provides for the collection of water samples with high, medium, or low suspended solids to determine the presence, count, polymer type, and physical characteristics of microplastic particles and fibers. This collection practice has been validated for the collection of samples from drinking water, surface waters, wastewater influent and effluent (secondary and tertiary), and marine waters. This practice is not limited to these particular water matrices; however, the applicability of this practice to other aqueous matrices must be demonstrated.1.2 Water samples are passed through filters or sieves of adequate mesh size to enable capture of the smallest desired particle size. For waters with high or medium suspended solids content, a series of sieves with increasingly smaller mesh size should be used to prevent clogging and allow for the collection of desired particle size fractions.1.3 Subsequent sample preparation followed by analysis utilizing either Pyrolysis gas chromatography/mass spectrometry (Py-GC/MS), IR spectroscopy, or Raman spectroscopy may be used to identify the quantity (mass or number count) and composition (polymer type) of microplastic particles/fibers. The spectroscopic methods can provide a count of the number of particles and fibers present in a sample, and Py-GC/MS can provide the mass present in a sample. When desired, microplastic particle/fiber size, shape and surface characteristics can be ascertained with appropriate instruments such as a scanning electron microscope (SEM).1.4 Units—The values stated in SI units are to be regarded as the standard except where standard U.S. equipment is specified in imperial units, for example, inches and gallons. No other units of measurement are included in this standard.1.5 Standard Practice—This practice offers a set of instructions for performing one or more specific operations. This practice 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 practice 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 practice be applied without consideration of a project’s many unique aspects.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 Large volumes of water are required to be sieved for accurate quantification of microplastics. Water with high to medium content of suspended solids can lead to an excess of inorganic and organic background material which can interfere with the ability to conduct reliable analyses. The presence of this background material can often impede the ability to accurately discern, distinguish and identify the number of microplastic particles in solution.5.2 The digestion described in this procedure allows for significant reduction of interfering substances and contaminants, rendering a sample suitable for particle and fiber characterization and identification using either Raman and IR spectroscopic analysis or for polymeric quantification and identification by Pyrolysis-GC/MS.5.3 For water samples with medium to low suspended solids, the oxidation and digestion steps necessary will be dependent upon the type and nature of interfering substances and contaminants and may be determined through simple trial efforts.1.1 This practice provides for the sample preparation of collected water samples with high, medium, or low suspended solids to determine the presence, count, polymer type, and physical characteristics of microplastic particles and fibers. It has been designed for the preparation of samples collected from drinking water, surface waters, wastewater influent and effluent (secondary and tertiary), and marine waters using collection practice (Practice D8332). This practice is not limited to these particular water matrices; however, the applicability of this practice to other aqueous matrices must be demonstrated.1.2 This practice consists of a wet peroxide oxidation followed by progressive enzymatic digestion to the extent necessary to remove interfering organic constituents such as cellulose, lipids and chitin that are typically found in abundance in water matrices of samples with high to medium suspended solids such as wastewater influent. For water samples with low suspended solids, such as but not limited to drinking water and tertiary treated wastewater, the oxidation and digestion steps may not be necessary.1.3 Water samples prepared using this practice are suitable for analysis utilizing either Pyrolysis-GC/MS methods for qualitative identification and mass quantitation, or IR spectroscopy or Raman spectroscopy for identifying the quantity (number count) and composition (polymer type) of microplastic particles. If desired, microplastic particle size and shape may be ascertained with appropriate instruments such as a scanning electron microscope (SEM) and microscopy techniques.1.4 Units—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： 515元 / 折扣价： 438 元 加购物车