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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

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5.1 Methanol and ethanol are generated by the degradation of cellulosic materials used in the solid insulation systems of electrical equipment. More particularly, methanol comes from the depolymerization of cellulosic materials.3, 4, 5, 65.2 Methanol and ethanol, which are soluble in an insulating liquid to an appreciable degree, will proportionally migrate to that liquid after being produced from the cellulose.5.3 High concentrations or unusual increases in the concentrations of methanol or ethanol, or both, in an insulating liquid may indicate cellulose degradation from aging or incipient fault conditions. Testing for these alcohols may be used to complement dissolved gas-in-oil analysis and furanic compounds as performed in accordance with Test Methods D3612 and D5837 respectively.1.1 This test method describes the determination of by-products of cellulosic materials degradation found in electrical insulation systems that are immersed in insulating liquid. Such materials include paper, pressboard, wood and cotton materials. This test method allows the analysis of methanol and ethanol from the sample matrix by headspace GC-MS or GC-FID.1.2 This test method has been used to test for methanol and ethanol in mineral insulating liquids and less flammable electrical insulating liquids of mineral origin as defined in D3487 and D5222 respectively. Currently, this method is not a practical application for ester liquids.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.

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5.1 Uranium material is used as a fuel in certain types of nuclear reactors. To be suitable for use as nuclear fuel, the starting material shall meet certain specifications such as those described in Specifications C753, C776, C787, C833, C967, C996, and C1008, or as specified by the purchaser. The 235U/238U isotope amount ratios and the amount content of uranium material can be measured by mass spectrometry following this test method to ensure that they meet the specification.5.2 The double spike method has been used for studies of uranium fractionation effects in isotope geochemistry and cosmochemistry, for uranium source attribution in nuclear forensics and for investigation of conversion or sampling processes in nuclear industry and nuclear safeguards (7-11). Most recently, the double spike method has been used for the validation of the Cristallini sampling method of UF6 (12 and 13). The double spike method can be used for a wide range of sample sizes even in samples containing as low as 50 μg of uranium. The concentration of the loading solution for the DS method has to be in the range of 1 to 6 mg/g to allow a sample loading of 4 to 6 μg of uranium. A minimum loading of 4 μg uranium per filament is recommended.5.3 The measurement of 236U/238U ratios using this method is not possible due to the large isobaric interference from the 236U ion beam of the double spike onto the 236U ion beam from the sample (>50.000 times for close to natural material, for example, like IRMM-184).5.4 The application of the double spike method for measurements of 235U/238U ratio is limited by the isobaric interference between the 236U from the double spike material and the 236U contained in the sample. As a consequence, the method is not suitable for samples which contain significant amounts of 236U due to prior neutron capture from 235U in the predecessor materials. For samples with 236U/238U ratios higher than about 10–6, the double spike method should be applied with care for the isobaric correction. For an appropriate isobaric correction, the 236U/238U ratios of the samples should be determined separately using a suitable measurement method, for example, the modified total evaporation MTE method (Test Method C1832, Ref (5) and (6)).5.5 The measurement of 234U/238U ratios using this method is very limited in the analytical performance due to the isobaric interference of the 234U from the double spike with the 234U from the sample (range from 5 to 15 %). The correction algorithms are presented in 14.3, but statements for precision and bias are not given. Other methods like MTE (Test Method C1832, Ref (5) and (6)) are better suited and more reliable for measurements of 234U/238U ratios.5.6 The DS method described here can also be extended to measurement of elements other than uranium, if a suitable double spike material is available.1.1 This test method describes the determination of the isotope amount ratios of uranium material as nitrate solutions by the double spike (DS) method using a thermal ionization mass spectrometer (TIMS) instrument.1.2 The analytical performance in the determination of the 235U/238U major isotope amount ratio by the DS method is five to ten times better in terms of the internal and external reproducibility compared to the (“classical”) total evaporation (TE) method as described in Test Method C1672 and the “modified total evaporation” (MTE) as described in Test Method C1832. This is due to the use of an internal rather than external mass fractionation correction by using a double spike material with a known or certified 233U/236U isotope ratio, which is mixed with the sample prior to the measurement, either during the sample preparation or directly on the TIMS filament.1.3 The DS method cannot be applied for the determination of the 236U/238U minor isotope amount ratio, and is also not recommended for the determination of the 234U/238U minor isotope amount ratio.1.4 In case the uranium amount concentration of the double spike is known or certified, the uranium amount concentration of the sample can be determined using the isotope dilution mass spectrometry (IDMS) method as described in Test Method C1672, by blending the sample gravimetrically with the double spike and performing a DS measurement.1.5 An external mass fractionation correction by measurements of a certified reference material loaded on different filaments and measured in the same measurement sequence, as recommended for TE and required for MTE measurements, is not necessary for the DS method. However, for quality control (QC) purposes it is recommended to perform DS measurements of low enriched or natural uranium isotopic reference materials on a regular basis.1.6 The DS method can only be applied to uranium samples with relative isotope abundances 233U/U below 10–5 and 236U/U below 5 × 10–4, the DS method is therefore mainly used for low enriched or close to natural uranium samples.1.7 Units—The values stated in SI units are to be regarded as the standard. When no SI units are provided, the values 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.

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5.1 Many regulators, industrial processes, and other stakeholders require determination of NMOC in atmospheres.5.2 Accurate measurements of ambient NMOC concentrations are critical in devising air pollution control strategies and in assessing control effectiveness because NMOCs are primary precursors of atmospheric ozone and other oxidants (7, 8).5.2.1 The NMOC concentrations typically found at urban sites may range up to 1 ppm C to 3 ppm C or higher. In order to determine transport of precursors into an area monitoring site, measurement of NMOC upwind of the site may be necessary. Rural NMOC concentrations originating from areas free from NMOC sources are likely to be less than a few tenths of 1 ppm C.5.3 Conventional test methods based upon gas chromatography and qualitative and quantitative species evaluation are relatively time consuming, sometimes difficult and expensive in staff time and resources, and are not needed when only a measurement of NMOC is desired. The test method described requires only a simple, cryogenic pre-concentration procedure followed by direct detection with an FID. This test method provides a sensitive and accurate measurement of ambient total NMOC concentrations where speciated data are not required. Typical uses of this standard test method are as follows.5.4 An application of the test method is the monitoring of the cleanliness of canisters.5.5 Another use of the test method is the screening of canister samples prior to analysis.5.6 Collection of ambient air samples in pressurized canisters provides the following advantages:5.6.1 Convenient collection of integrated ambient samples over a specific time period,5.6.2 Capability of remote sampling with subsequent central laboratory analysis,5.6.3 Ability to ship and store samples, if necessary,5.6.4 Unattended sample collection,5.6.5 Analysis of samples from multiple sites with one analytical system,5.6.6 Collection of replicate samples for assessment of measurement precision, and5.6.7 Specific hydrocarbon analysis can be performed with the same sample system.1.1 This test method2 presents a procedure for sampling and determination of non-methane organic compounds (NMOC) in ambient, indoor, or workplace atmospheres.1.2 This test method describes the collection of integrated whole air samples in silanized or other passivated stainless steel canisters, and their subsequent laboratory analysis.1.2.1 This test method describes a procedure for sampling in canisters at final pressures above atmospheric pressure (pressurized sampling).1.3 This test method employs a cryogenic trapping procedure for concentration of the NMOC prior to analysis.1.4 This test method describes the determination of the NMOC by the flame ionization detection (FID), without the use of gas chromatographic columns and other procedures necessary for species separation.1.5 The range of this test method is from 20 ppb C to 10 000 ppb C (1, 2).31.6 This test method has a larger uncertainty for some halogenated or oxygenated hydrocarbons than for simple hydrocarbons or aromatic compounds. This is especially true if there are high concentrations of chlorocarbons or chlorofluorocarbons present.1.7 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.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： 646元 / 折扣价： 550 元 加购物车

定价： 646元 / 折扣价： 550 元 加购物车

5.1 The presence of trace amounts of hydrogen, oxygen, carbon monoxide, and carbon dioxide can have deleterious effects in certain processes using hydrocarbon products as feed stock. This test method is suitable for setting specifications, for use as an internal quality control tool, and for use in development and research work.1.1 This test method covers the determination of hydrogen, nitrogen, oxygen, methane, carbon monoxide, and carbon dioxide in the parts per billion mole (nmol/mol) to parts per million mole (µmol/mol) range in C2 and C3 hydrocarbons.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. For some specific hazard statements, see Annex A1.1.3.1 The user is advised to obtain LPG safety training for the safe operation of this test method procedure and related activities.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