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

4.1 Although it is possible to observe and measure each of the several characteristics of a detector under different and unique conditions, it is the intent of this practice that a complete set of detector specifications be obtained at the same operating conditions, including geometry, flow rates, and temperatures. To specify a detector's capability completely, its performance should be measured at several sets of conditions within the useful range of the detector. The terms and tests described in this practice are sufficiently general so that they may be used under any chosen conditions.4.2 Linearity and speed of response of the recorder should be such that it does not distort or otherwise interfere with the performance of the detector. Effective recorder response should be sufficiently fast so that its effect on the sensitivity of measurement is negligible. If additional amplifiers are used between the detector and the final readout device, their characteristics should first be established.1.1 This practice covers testing the performance of a nitrogen/phosphorus thermionic ionization detector (NPD) used as the detection component of a gas chromatographic system.1.2 This practice applies to an NPD that employs a heated alkali metal compound and emits an electrical charge from that solid surface.1.3 This practice addresses the operation and performance of the NPD independently of the chromatographic column. However, the performance is specified in terms that the analyst can use to predict overall system performance when the detector is coupled to the column and other chromatographic components.1.4 For general chromatographic procedures, Practice E260 should be followed except where specific changes are recommended in this practice for the use of a nitrogen/phosphorus (N/P) thermionic detector.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. For specific safety information, see Section 5, Hazards.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

5.1 Uranium and plutonium oxides can be used as a nuclear-reactor fuel in the form of pellets. In order to be suitable for use as a nuclear fuel the starting material must meet certain specifications, such as found in Specifications C757, C833, C753, C776, C1008, or as specified by the purchaser. The uranium concentration, plutonium concentration, or both, and the isotopic abundances are measured by mass spectrometry following this test method.5.2 The separated heavy element fractions placed on mass spectrometric filaments must be very pure. The quantity required depends upon the sensitivity of the instrument detection system. If an electron multiplier detector is to be used, only a few nanograms are required. If a Faraday cup is used, a few micrograms are needed. Chemical purity of the sample becomes more important as the sample size decreases, because ion emission of the sample is suppressed by impurities.1.1 This test method covers the determination of the concentration and isotopic composition of uranium and plutonium in solutions. The purified uranium or plutonium from samples ranging from nuclear materials to environmental or bioassay matrices is loaded onto a mass spectrometric filament. The isotopic ratio is determined by thermal ionization mass spectrometry, the concentration is determined by isotope dilution.1.2 The values stated in SI units are to be regarded as the standard. Values 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 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 The total evaporation method is used to measure the isotopic composition of uranium, plutonium, and americium materials, and may be used to measure the elemental concentrations of these elements when employing the IDMS technique.5.2 Uranium and plutonium compounds are used as nuclear reactor fuels. In order to be suitable for use as a nuclear fuel the starting material must meet certain criteria, such as found in Specifications C757, C833, C753, C776, C787, C967, C996, or as specified by the purchaser. The uranium concentration, plutonium concentration, or both, and isotope abundances are measured by TIMS following this method.5.3 Americium-241 is the decay product of 241Pu isotope. The abundance of the 241Am isotope together with the abundance of the 241Pu parent isotope can be used to estimate radio-chronometric age of the Pu material for nuclear forensic applications Ref (6). The americium concentration and isotope abundances are measured by TIMS following this method.5.4 The total evaporation method allows for a wide range of sample loading with no significant change in precision or accuracy. The method is also suitable for trace-level loadings with some loss of precision and accuracy. The total evaporation method and modern instrumentation allow for the measurement of minor isotopes using ion counting detectors, while the major isotope(s) is(are) simultaneously measured using Faraday cup detectors.5.5 The new generation of miniaturized ion counters allow extremely small samples, in the picogram range, to be measured via the total evaporation method. The method may be employed for measuring environmental or safeguards inspection samples containing nanogram quantities of uranium or plutonium. Very small loadings require special sample handling and careful evaluation of measurement uncertainties.5.6 Typical uranium analyses are conducted using sample loadings between 50 nanograms and 800 nanograms. For uranium isotope ratios the total evaporation method had been used in several recent NBL isotopic certified reference material (CRM) characterizations (for example (2, 3)). A detailed comparison of the total evaporation data on NBL uranium CRMs analyzed by the MAT 261 and TRITONTM instruments is provided in Ref (5). For total evaporation, plutonium analyses are generally conducted using sample loads in the range of 20 to 200 nanograms of plutonium.1.1 This method describes the determination of the isotopic composition, or the concentration, or both, of uranium, plutonium, and americium as nitrate solutions by the total evaporation method using a thermal ionization mass spectrometer (TIMS) instrument. Purified uranium, plutonium, or americium nitrate solutions are deposited onto a metal filament and placed in the mass spectrometer. Under computer control, ion currents are generated by heating of the filament(s). The ion currents are continually measured until the whole deposited solution sample is exhausted. The measured ion currents are integrated over the course of the measurement and normalized to a reference isotope ion current to yield isotope ratios.1.2 In principle, the total evaporation method should yield isotope ratios that do not require mass bias correction. In practice, samples may require this bias correction. Compared to the conventional TIMS method described in Test Method C1625, the total evaporation method is approximately two times faster, improves precision of the isotope ratio measurements by a factor of two to four, and utilizes smaller sample sizes. Compared to the C1625 method, the total evaporation method provides “major” isotope ratios 235U/238U, 240Pu/239Pu, and 241Am/243Am with improved accuracy.1.3 The total evaporation method is prone to biases in the “minor” isotope ratios (233U/238U, 234U/238U, and 236U/238U ratios for uranium materials and 238Pu/239Pu, 241Pu/239Pu, 242Pu/239Pu, and 244Pu/239Pu ratios for plutonium materials) due to peak tailing from adjacent major isotopes. The magnitude of the absolute bias is dependent on measurement and instrumental characteristics. The relative bias, however, depends on the relative isotopic abundances of the sample. The use of an electron multiplier equipped with an energy filter may eliminate or diminish peak tailing effects. Measurement of the abundance sensitivity of the instrument may be used to ensure that such biases are negligible, or may be used to bias correct the minor isotope ratios.1.4 The values stated in SI units are to be regarded as standard. When non-SI units are provided in parentheses, they are for information only.1.5 This standard may involve the use of hazardous materials and equipment. This standard does not purport to address all 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 to 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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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.

定价： 515元 / 折扣价： 438 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

General Utility—The molecular mass (MM) and molecular mass distribution (MMD) are fundamental characteristics of a synthetic polymer that result from the polymerization process. The MM and MMD is useful for a wide variety of correlations for fundamental studies, processing and product applications. For example, it is possible to compare the observed MMD to predictions from an assumed kinetic or mechanistic model for the polymerization reaction. Differences between the values will allow alteration of the model or experimental design. Similarly, it is possible the strength, the melt flow rate, and other properties of a polymer are dependent on the MM and MMD. Determination of the MM and MMD are used for quality control of polymers and as specification in the commerce of polymers.Limitations—If the MMD is too wide, it is possible that the assumption of the constancy of the intensity scale calibration is in serious error.1.1 This test method covers the determination of molecular mass (MM) averages and the distribution of molecular masses for linear atactic polystyrene of narrow molecular mass distribution (MMD) ranging in molecular masses from 2000 g/mol to 35 000 g/mol by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). This test method is not absolute and requires the use of biopolymers for the calibration of the mass axis. The relative calibration of the intensity axis is assumed to be constant for a narrow MMD. Generally, this is viewed as correct if the measured polydispersity is less than 1.2 for the molecular mass range given above.1.2 The values stated in SI units are to be regarded as the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.Note 1—There is no known ISO equivalent to this standard.

定价： 0元 / 折扣价： 0 元

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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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

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.

定价： 646元 / 折扣价： 550 元 加购物车

5.1 In gasoline blending, the determination of organic oxygenated compounds is important. Alcohols, ethers, and other oxygenates are added to gasoline to increase the octane number and to reduce tailpipe emissions of carbon monoxide. They must be added in the proper concentration and ratios to meet regulatory limitations and to avoid phase separation and problems with engine performance or efficiency.5.2 This test method provides sufficient oxygen-to-hydro-carbon selectivity and sensitivity to allow determination of oxygenates in gasoline samples without interference from the bulk hydrocarbon matrix.1.1 This test method covers a gas chromatographic procedure for the quantitative determination of organic oxygenated compounds in gasoline having a final boiling point not greater than 220 °C and oxygenates having a boiling point limit of 130 °C. It is applicable when oxygenates are present in the 0.1 % to 20 % by mass range.1.2 This test method is intended to determine the mass concentration of each oxygenate compound present in a gasoline. This requires knowledge of the identity of each oxygenate being determined (for calibration purposes). However, the oxygen-selective detector used in this test method exhibits a response that is proportional to the mass of oxygen. It is, therefore, possible to determine the mass concentration of oxygen contributed by any oxygenate compound in the sample, whether or not it is identified. Total oxygen content in a gasoline may be determined from the summation of the accurately determined individual oxygenated compounds. The summed area of other, uncalibrated or unknown oxygenated compounds present, may be converted to a mass concentration of oxygen and summed with the oxygen concentration of the known oxygenated compounds.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 Although it is possible to observe and measure each of the several characteristics of a detector under different and unique conditions, it is the intent of this recommended practice that a complete set of detector specifications should be obtained at the same operating conditions, including geometry, flow rates, and temperatures. It should be noted that to specify a detector’s capability completely, its performance should be measured at several sets of conditions within the useful range of the detector. The terms and tests described in this recommended practice are sufficiently general so that they may be used at whatever conditions may be chosen for other reasons.4.2 The FID is generally only used with non-ionizable supercritical fluids as the mobile phase. Therefore, this standard does not include the use of modifiers in the supercritical fluid.4.3 Linearity and speed of response of the recording system or other data acquisition device used should be such that it does not distort or otherwise interfere with the performance of the detector. Effective recorder response, Bonsall (5) and McWilliam (6), in particular, should be sufficiently fast so that it can be neglected in sensitivity of measurements. If additional amplifiers are used between the detector and the final readout device, their characteristics should also first be established.1.1 This practice covers the testing of the performance of a flame ionization detector (FID) used as the detection component of a gas or supercritical fluid (SF) chromatographic system.1.2 This recommended practice is directly applicable to an FID that employs a hydrogen-air or hydrogen-oxygen flame burner and a dc biased electrode system.1.3 This recommended practice covers the performance of the detector itself, independently of the chromatographic column, the column-to-detector interface (if any), and other system components, in terms that the analyst can use to predict overall system performance when the detector is made part of a complete chromatographic system.1.4 For general gas chromatographic procedures, Practice E260 should be followed except where specific changes are recommended herein for the use of an FID. For definitions of gas chromatography and its various terms see recommended Practice E355.1.5 For general information concerning the principles, construction, and operation of an FID, see Refs (1, 2, 3, 4).21.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific safety information, see Section 5.1.8 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

4.1 For certain applications when insulating liquid is stressed at high voltage gradients, it is desirable to be able to determine the rate of gas evolution or gas absorption under specified test conditions. At present time correlation of such test results with equipment performance is limited.4.2 In this test method, hydrogen (along with low molecular weight hydrocarbons) is generated by ionic bombardment of some insulating liquid molecules and absorbed by chemical reaction with other insulating liquid molecules. The value reported is the net effect of these two competing reactions. The aromatic molecules or unsaturated portions of molecules present in insulating liquids are largely responsible for the hydrogen-absorbing reactions. Both molecule type, as well as concentration, affects the gassing tendency result. Saturated molecules tend to be gas evolving. The relation between aromaticity and quantity of unsaturates of the insulating liquid and gassing tendency is an indirect one and cannot be used for a quantitative assessment of either in the insulating liquid.4.3 This test method measures the tendency of insulating liquids to absorb or evolve gas under conditions of electrical stress and ionization based on the reaction with hydrogen, the predominant gas in the partial discharge. For the test conditions, the activating gas hydrogen, in contrast to other gases, for example, nitrogen, enhances the discrimination of differences in the absorption-evolution patterns exhibited by the insulating liquids. Insulating liquids shown to have gas-absorbing (H2) characteristics in the test have been used to advantage in reducing equipment failures, particularly cables and capacitors. However, the advantage of such insulating liquids in transformers is not well defined and there has been no quantitative relationship established between the gassing tendency as indicated by this test method and the operating performance of the equipment. This test method is not concerned with bubble evolution, which may arise from physical processes associated with super-saturation of gases in oil or water vapor bubbles evolving from wet insulation.1.1 This test method measures the rate at which gas is evolved or absorbed by insulating liquids when subjected to electrical stress of sufficient intensity to cause ionization in cells having specific geometries.1.2 This test method is not concerned with bubbles arising from supersaturation of the insulating liquid.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 whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautions see 5.1.4 and 8.4.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This test method covers the determination of the dissolved gases methane, ethane, ethylene, and propane in drinking, waste, and ground waters, including domestic wells; whether naturally occurring or resulting from commercial activities, dissolved gases can be hazardous both to the environment and humans. Due to increased scrutiny of dissolved gases, developing a valid method for the testing of dissolved gases in water has become more imperative. Static headspace sampling is generally applicable for sampling these compounds. However, as these compounds are extremely volatile, a closed sampling system is recommended. This test method can be used for quantitatively determining dissolved gases in ground, waste, and drinking waters.5.2 This test method is suitable for analysis of domestic drinking water samples from residential and commercial water supply wells prior to oil and gas exploration activities to form a baseline for monitoring potential impacts during exploration; development, including hydraulic fracturing; operation; closure; and reclamation of nearby oil and gas production and injection wells.1.1 This test method covers the determination of the dissolved gases methane, ethane, ethylene, and propane in drinking, waste, and ground waters, including domestic wells whether naturally occurring or resulting from commercial activities, or both. This test method has an analytical range from 10 µg/L to 11 000 µg/L for methane, and 10 µg/L to 5000 µg/L for ethane, ethylene, and propane. If a sample has a dissolved gas concentration above the calibration range, the sample would require dilution. Other analytical ranges may be used as long as the instrument calibration encompasses the desired range and demonstrates adequate linearity.1.2 This test method is applicable to samples collected at a nominal ambient pressure. Samples collected under high pressures, that is, above ambient pressure, may not be accurately analyzed using this method.1.3 This test method is applicable to a variety of dissolved gases; however, for the present standard, only methane, ethane, ethylene, and propane were validated. In order to validate for a gas not listed in this method, the analyst would need to establish the saturation concentration of the new gas, and establish a valid curve, method detection limits, and demonstration of capability following the procedures outlined in this method.1.4 It is the analyst’s responsibility to ensure the validity of this test method for dissolved gases other than methane, ethane, ethylene, and propane and other sample matrices.1.5 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.6 A single laboratory study was done in order to establish precision and bias for the surrogate (see Section 16).1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 646元 / 折扣价： 550 元 加购物车