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5.1 Uranium hexafluoride used to produce nuclear fuel must meet certain criteria for its isotopic composition as described in Specifications C787 and C996.1.1 This method applies to the determination of isotopic composition in hydrolyzed nuclear grade uranium hexafluoride. It covers isotopic abundance of  235U between 0.1 and 5.0 % mass fraction, abundance of  234U between 0.0055 and 0.05 % mass fraction, and abundance of   236U between 0.0003 and 0.5 % mass fraction. This test method may be applicable to other isotopic abundance providing that corresponding standards are available.1.2 This test method can apply to uranyl nitrate solutions. This can be achieved either by transforming the uranyl nitrate solution to a uranyl fluoride solution prior to the deposition on the filaments or directly by depositing the uranyl nitrate solution on the filaments. In the latter case, a calibration with uranyl nitrate standards must be performed.1.3 This test method can also apply to other nuclear grade matrices (for example, uranium oxides) by providing a chemical transformation to uranyl fluoride or uranyl nitrate solution.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.

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定价： 590元 / 折扣价： 502 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This test method is of particular use as a quality control tool for a molding or synthesis operation. Acetaldehyde is a volatile degradation product generated during melt processing of PET. Thus, it becomes trapped in the sidewalls of a molded article and desorbs slowly into the contents packaged therein. In some foods and beverages AA can impart an off-taste that is undesirable, thus, it is important to know its concentration in PET articles that are to be used in food contact applications.5.2 The desorption conditions of 150 °C for 60 min are such that no measurable AA is generated by the sample during the desorption process.1.1 This test method covers a gas chromatographic procedure for the determination of the ppm residual acetaldehyde (AA) present in poly(ethylene terephthalate) (PET) homo-polymers and co-polymers which are used in the manufacture of beverage bottles. This includes sample types of both amorphous and solid-stated pellet and preform samples, as opposed to the bottle test, Test Method D4509, an acetaldehyde test requiring 24 h of desorption time at 23 °C into the bottle headspace and then the concentration of the headspace quantified by a similar GC method.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： 590元 / 折扣价： 502 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

定价： 646元 / 折扣价： 550 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

1.1 This test method covers the measurement of volatile organic-vapor-barrier properties of films, plastic sheeting, coated papers, and laminates. The specific material properties measured include diffusivity, solubility, and permeability coefficients; parameter values which are required for the solution of mass transfer problems associated with nonsteady state and steady state conditions. 1.2 Applicable test vapors include volatile organic compounds which are detectable by a flame ionization detector. Examples of applicable permeation compounds include solvents, organic film additives, flavor compounds, and aroma compounds. 1.3 This test method assumes the material being measured exhibits Fickian behavior and uses the solutions to Fick's Laws for a planar surface as the data regression model. (See Annex A1.) 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.

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4.1 Although Co-60 nuclei only emit monoenergetic gamma rays at 1.17 and 1.33 MeV, the finite thickness of sources, and encapsulation materials and other surrounding structures that are inevitably present in irradiators can contribute a substantial amount of low-energy gamma radiation, principally by Compton scattering (1, 2).3 In radiation-hardness testing of electronic devices this low-energy photon component of the gamma spectrum can introduce significant dosimetry errors for a device under test since the equilibrium absorbed dose as measured by a dosimeter can be quite different from the absorbed dose deposited in the device under test because of absorbed dose enhancement effects (3, 4). Absorbed dose enhancement effects refer to the deviations from equilibrium absorbed dose caused by non-equilibrium electron transport near boundaries between dissimilar materials.4.2 The ionization chamber technique described in this method provides an easy means for estimating the importance of the low-energy photon component of any given irradiator type and configuration.4.3 When there is an appreciable low-energy spectral component present in a particular irradiator configuration, special experimental techniques should be used to ensure that dosimetry measurements adequately represent the absorbed dose in the device under test. (See Practice E1249.)1.1 Low energy components in the photon energy spectrum of Co-60 irradiators lead to absorbed dose enhancement effects in the radiation-hardness testing of silicon electronic devices. These low energy components may lead to errors in determining the absorbed dose in a specific device under test. This method covers procedures for the use of a specialized ionization chamber to determine a figure of merit for the relative importance of such effects. It also gives the design and instructions for assembling this chamber.1.2 This method is applicable to measurements in Co-60 radiation fields where the range of exposure rates is 7 × 10 −6 to 3 × 10−2 C kg −1 s−1 (approximately 100 R/h to 100 R/s). For guidance in applying this method to radiation fields where the exposure rate is >100 R/s, see Appendix X1.NOTE 1: See Terminology E170 for definition of exposure and its units.1.3 The values stated in SI units are to be regarded as the 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： 702元 / 折扣价： 597 元 加购物车

This practice provides application criteria, definitions, and supplemental information to assist the user in obtaining meaningful vacuum ionization gage measurements in space-simulation facilities. Acceptable vacuum-measuring equipment shall consist of those items in which performance is compatible with obtaining meaningful measurements. The gage mounting, gage orientation, gage operational error, and gage correction for gas composition are presented in details. The gas composition determination, operating criteria, heavy molecular weight contamination effects, apparent X-ray limit for hot-cathode gages, and cold cathode gages are presented in details.1.1 This practice provides application criteria, definitions, and supplemental information to assist the user in obtaining meaningful vacuum ionization gage measurements below 10−1 N/m2 (10−3 torr) in space-simulation facilities. Since a variety of influences can alter observed vacuum measurements, means of identifying and assessing potential problem areas receive considerable attention. This practice must be considered informational, for it is impossible to specify a means of applying the vacuum-measuring equipment to guarantee accuracy of the observed vacuum measurement. Therefore, the user's judgment is essential so that if a problem area is identified, suitable steps can be taken to either minimize the effect, correct the observed readings as appropriate, or note the possible error in the observation.1.2 While much of the discussion is concerned with the application of hot-cathode ionization gages, no exclusion is made of cold-cathode designs. Since a great deal more experience with hot-cathode gages is available and hot-cathode devices are used in the majority of applications, the present emphasis is fully warranted.1.3 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 The determination of oxygenates is important in the manufacture of ethene, propene, 1-3 butadiene, C4 hydrocarbons, and C5 hydrocarbons. Alcohols, ethers, aldehydes, and ketones are trace impurities in these hydrocarbons. Oxygenates decrease catalyst activity in downstream polymerization processes.1.1 This test method covers the gas chromatographic procedure for the quantitative determination of organic oxygenates in C2, C3, C4, and C5 matrices by multidimensional gas chromatography and flame ionization detection. This test method is applicable when the hydrocarbon matrices have a final boiling point not greater than 200 °C. Oxygenate compounds include, but are not limited to, those listed in Table 1. The linear working range for oxygenates is 0.50 mg/kg to 100 mg/kg.1.2 This test method is intended to determine the mass concentration of each oxygenate in the hydrocarbon matrix. Oxygenate compound identification is determined by reference standards and column elution retention order.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.1.4.1 The user is advised to obtain LPG safety training for the safe operation of this test method procedure and related activities. The eLearning training course “Liquefied Petroleum Gases Sampling Safety” is available on the ASTM.org website.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

定价： 515元 / 折扣价： 438 元 加购物车