5.1 The significance of this practice is adequately covered in Section 1.1.1 This practice is a general guide for ambient air analyzers used in determining air quality.1.2 The actual method, or analyzer chosen, depends on the ultimate aim of the user: whether it is for regulatory compliance, process monitoring, or to alert the user of adverse trends. If the method or analyzer is to be used for federal or local compliance, it is recommended that the method published or referenced in the regulations be used in conjunction with this and other ASTM methods.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. For specific hazard statements, see Section 6.1.5 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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定价： 590元 / 折扣价： 502 元 加购物车

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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

定价： 590元 / 折扣价： 502 元 加购物车

1.1 This test method covers procedures for the use of oxygen analyzers to measure the percentage of oxygen in an insulating glass unit where normal atmospheric air has been replaced with other gases such as argon, krypton, xenon, or sulfur hexafluoride (SF6). The procedure shows how to convert the measured percentage of oxygen in an insulating glass unit to the percentage of air in the unit, and subtracts the air percentage from 100 % to calculate the percentage of fill gas in the unit.1.2 This test method does not determine the type of fill gas. It only measures the percentage of oxygen in the gas in the space between the lites of an insulating glass unit.1.3 This test method is not applicable to insulating glass units containing open capillary/breather tubes.1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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 and health practices and determine the applicability of regulatory limitations prior to use.

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5.1 Density is a fundamental physical property that may be used in conjunction with other properties to characterize the quality of crude oils.5.2 The density or relative density of crude oils is used for the conversion of measured volumes to volumes at the standard temperatures of 15 °C or 60 °F and for the conversion of crude mass measurements into volume units.5.3 The application of the density result obtained from this test method, for fiscal or custody transfer accounting calculations, may require measurements of the water and sediment contents obtained on similar specimens of the crude oil parcel.1.1 This test method covers the determination of the density, relative density, and API gravity of crude oils that may be handled in a normal fashion as liquids at test temperatures between 15 °C and 35 °C utilizing either manual or automated sample injection equipment. This test method applies to crude oils with high vapor pressures provided appropriate precautions are taken to prevent vapor loss during transfer of the sample to the density analyzer.1.2 This test method was evaluated in interlaboratory study testing using crude oils in the 0.75 g/mL to 0.95 g/mL range. Lighter crude oil may require special handling to prevent vapor losses.1.3 The values stated in SI units are to be regarded as standard. Other units of measurement are included in this standard. The accepted units of measurement of density are grams per millilitre and kilograms per cubic metre.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. Specific warning statements are given in 7.4, 7.5, and 7.6.1.5 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 Automatic determination of stability parameters using a light back-scattering technique improves accuracy and removes human errors. In manual testing, operators have to visually compare oil stains on pieces of filter paper to determine if asphaltenes have been precipitated.5.2 Refinery thermal and hydrocracking processes can be run closer to their severity limits if stability parameters can be calculated more accurately. This gives increased yield and profitability.5.3 Results from the test method could be used to set a standard specification for stability parameters for fuel oils.5.4 The compatibility parameters of crude oils can be used in crude oil blending in refineries to determine, in advance, which crude oil blends will be compatible and thus can be used to minimize plugging problems, unit shut downs, and maintenance costs. Determination of crude oil compatibility parameters also enables refineries to select crude oil mixtures more economically.5.5 This test method can measure stability and compatibility parameters, and determine stability reserve on different blends for particular applications to optimize the blending, storage, and use of heavy fuel oilsNOTE 1: Users of this test method would normally use stability and compatibility parameters to determine stability reserve of residual products, fuel blends and crude oils. However, the interpretation of stability, stability reserve and compatibility is heavily ‘use dependent,’ and is beyond the scope of this test method.1.1 This test method covers an automated procedure involving titration and optical detection of precipitated asphaltenes for determining the stability and compatibility parameters of refinery residual streams, residual fuel oils, and crude oils. Stability in this context is the ability to maintain asphaltenes in a peptized or dissolved state and not undergo flocculation or precipitation. Similarly, compatibility relates to the property of mixing two or more oils without precipitation or flocculation of asphaltenes.1.2 This test method is applicable to residual products from atmospheric and vacuum distillation, from thermal, catalytic, and hydrocracking processes, to products typical of Specifications D396, Grades No. 5L, 5H, and 6, and D2880, Grades No. 3-GT and 4-GT, and to crude oils, providing these products contain 0.05 mass % or greater concentration of asphaltenes.1.3 This test method is not relevant to oils that contain less than 0.05 % asphaltenes, and would be pointless to apply to unstable oils that already contain flocculated asphaltenes.1.4 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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6.1 Test Method A is the most frequently used in leak testing components which are structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10−3 torr). Testing of small components can be correlated to calibrated leaks, and the actual leak rate can be measured or acceptance can be based on a maximum allowable leak. For most production needs acceptance is based on acceptance of parts leaking less than an established standard which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with reference leak at a representative place on the test volume. Leak rates are determined by calculating the net gain or loss through a leak in the test part that would cause failure during the expected life of the device.6.2 Test Method B is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test or for conditioning parts. As the volume tends to be large, a check of the response time as well as system sensitivity should be made. Volume of the system in liters divided by the speed of the vacuum pump in L/s will give the response time to reach 63 % of the total signal. Response times in excess of a few seconds makes leak detection difficult.6.3 Test Method C is to be used only when there is no convenient method of connecting the leak detector to the outlet of the high vacuum pump. If a helium leak detector is used and the high vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle as these pumps leave a relatively high percentage of helium in the high vacuum chamber. This will obscure all but large leaks, and the trace gas will quickly saturate the pumps.1.1 This practice covers procedures for testing and locating the sources of gas leaking at the rate of 1 × 10 −8 Pa m3/s (1 × 10−9 Std cm 3/s)3 or greater. The test may be conducted on any object to be tested that can be evacuated and to the other side of which helium or other tracer gas may be applied.1.2 Three test methods are described:1.2.1 Test Method A—For the object under test capable of being evacuated, but having no inherent pumping capability.1.2.2 Test Method B—For the object under test with integral pumping capability.1.2.3 Test Method C—For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector.1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the 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 Proton exchange membranes (PEM) used in fuel cells are susceptible to contamination from a number of species that can be found in hydrogen. It is critical that these contaminants be measured and verified to be present at or below the amounts stated in SAE J2719 and ISO 14687 to ensure both fuel cell longevity and optimum efficiency. Contaminant concentrations as low as single-figure ppb(v) for some species can seriously compromise the life span and efficiency of PEM fuel cells. The presence of contaminants in fuel-cell-grade hydrogen can, in some cases, have a permanent adverse impact on fuel cell efficiency and usability. It is critical to monitor the concentration of key contaminants in hydrogen during the production phase through to delivery of the fuel to a fuel cell vehicle or other PEM fuel cell application. In ISO 14687, the upper limits for the contaminants are specified. Refer to SAE J2719 (see 2.3) for specific national and regional requirements. For hydrogen fuel that is transported and delivered as a cryogenic liquid, there is additional risk of introducing impurities during transport and delivery operations. For instance, moisture can build up over time in liquid transfer lines, critical control components, and long-term storage facilities, which can lead to ice buildup within the system and subsequent blockages that pose a safety risk or the introduction of contaminants into the gas stream upon evaporation of the liquid. Users are reminded to consult Practice D7265 for critical thermophysical properties such as the ortho/para hydrogen spin isomer inversion that can lead to additional hazards in liquid hydrogen usage.1.1 This test method describes contaminant determination in fuel cell grade hydrogen as specified in relevant ASTM and ISO standards using cavity ring-down spectroscopy (CRDS). This standard test method is for the measurement of one or multiple contaminants including, but not limited to, water (H2O), oxygen (O2), methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), ammonia (NH3), and formaldehyde (H2CO), henceforth referred to as “analyte.”1.2 This test method applies to CRDS analyzers with one or multiple sensor modules (see 6.2 for definition). This test method describes sampling apparatus design, operating procedures, and quality control procedures required to obtain the stated levels of precision and accuracy.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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.1.4 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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定价： 646元 / 折扣价： 550 元 加购物车