定价： 553元 / 折扣价： 471 元 加购物车

This specification deals with the standard structural quality of high-strength low-alloy nickel, copper, phosphorus steel H-piles and sheet piling for use in the construction of dock walls, bulkheads, excavations, and like applications in marine environments. The steel shall be semi-killed or killed and shall be exposed to the washing action of rain and the drying action of wind or sun, or both to determine its atmospheric corrosion resistance. Material specimens shall undergo product analysis, heat analysis, and tension testing and shall conform to the required chemical composition, tolerance, tensile strength, yield point, and elongation specifications.1.1 This specification covers high-strength low-alloy nickel, copper, phosphorus steel H-piles and sheet piling of structural quality for use in the construction of dock walls, sea walls, bulkheads, excavations, and like applications in marine environments.1.2 The atmospheric corrosion resistance of this steel is substantially better than that of ordinary carbon steels with or without copper addition (see Note 1). The steel has also shown to have substantially greater resistance to seawater “Splash Zone” corrosion than ordinary carbon steel (Specifications A36/A36M and A328/A328M) where exposed to the washing action of rain and the drying action of the wind or sun, or both. Where the steel is not boldly exposed, the usual provisions for the protection of ordinary carbon steel should be considered.NOTE 1: For methods of estimating atmospheric corrosion resistance of low-alloy steels, see Guide G101.1.3 When the steel is to be welded, it is presupposed that a welding procedure suitable for the grade of steel and intended use or service will be utilized. See Appendix X3 of Specification A6/A6M for information on weldability.1.4 The values stated in either inch-pound units or SI units are to be regarded as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.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

5.1 The distillation (volatility) characteristics of hydrocarbons and other liquids have an important effect on their safety and performance, especially in the case of fuels and solvents. The boiling range gives information on the composition, the properties, and the behavior of the fuel during storage and use. Volatility is the major determinant of the tendency of a hydrocarbon mixture to produce potentially explosive vapors.5.2 The distillation characteristics are equally important for both automotive and aviation gasolines, affecting starting, warm-up, and tendency to vapor lock at high operating temperatures or high altitude, or both. The presence of high boiling point components in these and other fuels can significantly affect the degree of formation of solid combustion deposits.5.3 Volatility, as it affects the rate of evaporation, is an important factor in the application of many solvents, particularly those used in paints.5.4 Distillation limits are often included in petroleum product specifications, in commercial contract agreements, process refinery/control applications, and for compliance to regulatory rules.5.5 This test method is suitable for setting specifications, for use as an internal quality control tool, and for use in development or research work on hydrocarbon solvents.5.5.1 This test method gives a broad indication of general purity and can also indicate presence of excessive moisture. It will not differentiate between products of similar boiling range.1.1 This test method covers the procedure for the determination of the distillation characteristics of petroleum products and liquid fuels in the range of 20 °C to 400 °C (68 °F to 752 °F) using miniaturized automatic distillation apparatus.1.2 This test method is applicable to such products as: light and middle distillates, automotive spark-ignition engine fuels, automotive spark-ignition engine fuels containing up to 10 % ethanol, aviation gasolines, aviation turbine fuels, all grades of No. 1 and No. 2 diesel fuels (as described in Specification D975), biodiesel (B100), biodiesel blends up to 30 % biodiesel, special petroleum spirits, pure petrochemical compounds, naphthas, white spirits, kerosenes, furnace fuel oils, and distillate marine fuels.NOTE 1: The up to 10 % by volume ethanol limit in spark ignition engine fuels (E10) was the range used in the supporting interlaboratory studies. Spark ignition engine fuels containing > 10 % by volume ethanol and up to 20 % by volume ethanol (E20) may be analyzed, however the stated precision and bias does not apply.1.3 This test method is designed for the analysis of distillate products; it is not applicable to products containing appreciable quantities of residual material.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, 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： 777元 / 折扣价： 661 元 加购物车

5.1 The distillation (volatility) characteristics of hydrocarbons and other liquids have an important effect on their safety and performance, especially in the case of fuels and solvents. The boiling range gives information on the composition, the properties, and the behavior of the fuel during storage and use. Volatility is the major determinant of the tendency of a hydrocarbon mixture to produce potentially explosive vapors.5.2 The distillation characteristics are critically important for both automotive and aviation gasolines, affecting starting, warm-up, and tendency to vapor lock at high operating temperature or at high altitude, or both. The presence of high boiling point components in these and other fuels can significantly affect the degree of formation of solid combustion deposits.5.3 Distillation limits are often included in petroleum product specifications, in commercial contract agreements, process refinery/control applications, and for compliance to regulatory rules.5.4 This test method can be applied to contaminated products or hydrocarbon mixtures. This is valuable for fast product quality screening, refining process monitoring, fuel adulteration control, or other purposes including use as a portable apparatus for field testing.5.5 This test method uses an automatic micro distillation apparatus, provides fast results using small sample volume, and eliminates much of the operator time and subjectivity in comparison to Test Method D86.1.1 This test method covers a procedure for determination of the distillation characteristics of petroleum products and liquid fuels having boiling range between 20 °C to 400 °C at atmospheric pressure using an automatic micro distillation apparatus.1.2 This test method is applicable to such products as; light and middle distillates, automotive spark-ignition engine fuels, automotive spark-ignition engine fuels containing up to 20 % ethanol, aviation gasolines, aviation turbine fuels, regular and low sulfur diesel fuels, biodiesel (B100), biodiesel blends up to 20 % biodiesel, special petroleum spirits, naphthas, white spirits, kerosines, burner fuels, and marine fuels.1.3 The test method is also applicable to hydrocarbons with a narrow boiling range, like organic solvents or oxygenated compounds.1.4 The test method is designed for the analysis of distillate products; it is not applicable to products containing appreciable quantities of residual material.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： 843元 / 折扣价： 717 元 加购物车

5.1 In the past, ASTM specifications for low-alloy weathering steels, such as Specifications A242/A242M, A588/A588M, A606/A606M Type 4, A709/A709M Grade 50W, HPS 70W, and 100W, A852/A852M, and A871/A871M stated that the atmospheric corrosion resistance of these steels is “approximately two times that of carbon structural steel with copper.” A footnote in the specifications stated that “two times carbon structural steel with copper is equivalent to four times carbon structural steel without copper (Cu 0.02 maximum).” Because such statements relating the corrosion resistance of weathering steels to that of other steels are imprecise and, more importantly, lack significance to the user (1 and 2),4 the present guide was prepared to describe more meaningful methods of estimating the atmospheric corrosion resistance of weathering steels.5.2 The first method of this guide is intended for use in estimating the expected long-term atmospheric corrosion losses of specific grades of low-alloy steels in various environments, utilizing existing short-term atmospheric corrosion data for these grades of steel.5.3 The second method of this guide is intended for use in estimating the relative atmospheric corrosion resistance of a specific heat of low-alloy steel, based on its chemical composition.5.4 It is important to recognize that the methods presented here are based on calculations made from test data for flat, boldly exposed steel specimens. Atmospheric corrosion rates can be much higher when the weathering steel remains wet for prolonged periods of time, or is heavily contaminated with salt or other corrosive chemicals. Therefore, caution must be exercised in the application of these methods for prediction of long-term performance of actual structures.1.1 This guide presents two methods for estimating the atmospheric corrosion resistance of low-alloy weathering steels, such as those described in Specifications A242/A242M, A588/A588M, A606/A606M Type 4, A709/A709M grades 50W, HPS 70W, and 100W, A852/A852M, and A871/A871M. One method gives an estimate of the long-term thickness loss of a steel at a specific site based on results of short-term tests. The other gives an estimate of relative corrosion resistance based on chemical composition.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 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 dioxide is used as a nuclear-reactor fuel. This test method is designed to determine whether the percent uranium and O/U or O/M content meet Specifications C776 and C922.1.1 This test method applies to the determination of uranium, the oxygen to uranium (O/U) ratio in sintered uranium dioxide pellets, and the oxygen to metal (O/M) ratio in sintered gadolinium oxide-uranium dioxide pellets with a Gd2O3 concentration of up to 12 weight %. The O/M calculations assume that the gadolinium and uranium oxides are present in a metal dioxide solid solution.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 specific hazards statements, see Section 9.1.4 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 basic test method of determining the boiling range of a petroleum product by performing a simple batch distillation has been in use as long as the petroleum industry has existed. It is one of the oldest test methods under the jurisdiction of ASTM Committee D02, dating from the time when it was still referred to as the Engler distillation. Since the test method has been in use for such an extended period, a tremendous number of historical data bases exist for estimating end-use sensitivity on products and processes.5.2 The distillation (volatility) characteristics of hydrocarbons have an important effect on their safety and performance, especially in the case of fuels and solvents. The boiling range gives information on the composition, the properties, and the behavior of the fuel during storage and use. Volatility is the major determinant of the tendency of a hydrocarbon mixture to produce potentially explosive vapors.5.3 The distillation characteristics are critically important for both automotive and aviation gasolines, affecting starting, warm-up, and tendency to vapor lock at high operating temperature or at high altitude, or both. The presence of high boiling point components in these and other fuels can significantly affect the degree of formation of solid combustion deposits.5.4 Volatility, as it affects rate of evaporation, is an important factor in the application of many solvents, particularly those used in paints.5.5 Distillation limits are often included in petroleum product specifications, in commercial contract agreements, process refinery/control applications, and for compliance to regulatory rules.1.1 This test method covers the atmospheric distillation of petroleum products and liquid fuels using a laboratory batch distillation unit to determine quantitatively the boiling range characteristics of such products as light and middle distillates, automotive spark-ignition engine fuels with or without oxygenates (see Note 1), aviation gasolines, aviation turbine fuels, diesel fuels, biodiesel blends up to 30 % volume, marine fuels, special petroleum spirits, naphthas, white spirits, kerosines, and Grades 1 and 2 burner fuels.NOTE 1: An interlaboratory study was conducted in 2008 involving 11 different laboratories submitting 15 data sets and 15 different samples of ethanol-fuel blends containing 25 % volume, 50 % volume, and 75 % volume ethanol. The results indicate that the repeatability limits of these samples are comparable or within the published repeatability of the method (with the exception of FBP of 75 % ethanol-fuel blends). On this basis, it can be concluded that Test Method D86 is applicable to ethanol-fuel blends such as Ed75 and Ed85 (Specification D5798) or other ethanol-fuel blends with greater than 10 % volume ethanol. See ASTM RR:D02-1694 for supporting data.21.2 The test method is designed for the analysis of distillate fuels; it is not applicable to products containing appreciable quantities of residual material.1.3 This test method covers both manual and automated instruments.1.4 Unless otherwise noted, the values stated in SI units are to be regarded as the standard. The values given in parentheses are provided for information only.1.5 WARNING—Mercury has been designated by many regulatory agencies as a hazardous substance that can cause serious medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Use Caution when handling mercury and mercury-containing products. See the applicable product Safety Data Sheet (SDS) for additional information. The potential exists that selling mercury or mercury-containing products, or both, is prohibited by local or national law. Users must determine legality of sales in their location.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： 843元 / 折扣价： 717 元 加购物车

This guide describes quality assurance protocols for the determination of the anions and cations in atmospheric wet deposition which include the minimum recommended requirements for the preparation of calibration standards and suggested procedures for validating laboratory measurement results. Specimens to be used in all tests shall consist of reagent grade chemicals, water, and standard solutions. Common techniques for chemical analysis include automated colorimetry; ion chromatography, flame atomic absorption spectrophotometry, electrometry, and inductively coupled plasma spectrometry. Analytical precision and bias determinations shall be done for evaluation of the reference materials. Samples for reanalysis may be selected from the evaluation of control charts and the calculation of ion and conductivity percent differences.1.1 This guide describes quality assurance (QA) protocols for the determination of the anions and cations in Atmospheric Wet Deposition (AWD) shown in Table 1.1.2 Included in this guide are minimum recommended requirements for the preparation of calibration standards and suggested procedures for validating laboratory measurement results.1.3 This guide describes minimum requirements for the frequency of analysis of quality assurance samples and recommends procedures for the evaluation of quality assurance data.1.4 The guide's recommendations are based upon expected anion and cation concentrations in AWD (1)2 and Appendix X1.1.5 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

5.1 The small size of the wire compared to the short galvanic interaction distance in atmospheric exposures gives a large cathode-to-anode area ratio which accelerates the galvanic attack. The area between the wire and the threads creates a long, tight crevice, also accelerating the corrosion. For these reasons, this practice, with a typical exposure period of 90 days, is the most rapid atmospheric galvanic corrosion test, particularly compared to Test Method G104. The short duration of this test means that seasonal atmospheric variability can be evaluated. (If average performance over a 1-year period is desired, several staggered exposures are required with this technique.) Reproducibility of this practice is somewhat better than other atmospheric galvanic corrosion tests.5.2 The major disadvantage of this test is that the anode material must be available in wire form and the cathodic material must be available in the form of a threaded rod. This should be compared to Test Method G104 where plate or sheet material is used exclusively.5.3 An additional limitation is that the more anodic material of the pair must be known beforehand (from information such as in Guide G82) or assemblies must be made with the material combinations reversed.5.4 The morphology of the corrosion attack or its effect on mechanical properties of the base materials cannot be assessed by this practice. Test Method G104 is preferable for this purpose.5.5 This test has been used under the names CLIMAT and ATCORR to determine atmospheric corrosivity by exposing identical specimens made from 1100 aluminum (UNS A91100) wire wrapped around threaded rods of nylon, 1010 mild steel (UNS G10100 or G10080), and CA110 copper (UNS C11000). Atmospheric corrosivity is a function of the material that is corroding, however. The relative corrosivity of atmospheres could be quite different if a different combination of materials is chosen.1.1 This practice covers the evaluation of atmospheric galvanic corrosion of any anodic material that can be made into a wire when in contact with a cathodic material that can be made into a threaded rod.1.2 When certain materials are used for the anode and cathode, this practice has been used to rate the corrosivity of atmospheres.1.3 The wire-on-bolt test was first described in 1955 (1),2 and has since been used extensively with standard materials to determine corrosivity of atmospheres under the names CLIMAT Test (CLassify Industrial and Marine ATmospheres) (2-5) and ATCORR (ATmospheric CORRosivity) (6-9).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.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 Some chemical constituents of AWD are not stable and must be preserved before chemical analysis. Without sample preservation, it is possible that analytes can be lost through decomposition or sorption to the storage bottles.4.2 Contamination of AWD samples can occur during both sample preservation and sample storage. Proper selection and cleaning of sampling containers are required to reduce the possibility of contamination of AWD samples.4.3 The natural sponge and talc-free plastic gloves used in the following procedures should be recognized as potential sources of contamination. Individual experience should be used to select products that minimize contamination.1.1 This practice presents recommendations for the cleaning of plastic or glass materials used for collection of atmospheric wet deposition (AWD). This practice also presents recommendations for the preservation of samples collected for chemical analysis.1.2 The materials used to collect AWD for the analysis of its inorganic constituents and trace elements should be plastic. High density polyethylene (HDPE) is most widely used and is acceptable for most samples including samples for the determination of the anions of acetic, citric, and formic acids. Borosilicate glass is a collection alternative for the determination of the anions from acetic, citric, and formic acid; it is recommended for samples for the determination of other organic 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

5.1 Atmospheric pressure is one of the basic variables used by meteorologists to describe the state of the atmosphere.5.2 The measurement of atmospheric pressure is needed when differences from “standard” pressure conditions must be accounted for in some scientific and engineering applications involving pressure dependent variables.5.3 These test methods provide a means of measuring atmospheric pressure with the accuracy and precision comparable to the accuracy and precision of measurements made by governmental meteorological agencies.1.1 These test methods cover the measurement of atmospheric pressure with two types of barometers: the Fortin-type mercurial barometer and the aneroid barometer.1.2 In the absence of abnormal perturbations, atmospheric pressure measured by these test methods at a point is valid everywhere within a horizontal distance of 100 m and a vertical distance of 0.5 m of the point.1.3 Atmospheric pressure decreases with increasing height and varies with horizontal distance by 1 Pa/100 m or less except in the event of catastrophic phenomena (for example, tornadoes). Therefore, extension of a known barometric pressure to another site beyond the spatial limits stated in 1.2 can be accomplished by correction for height difference if the following criteria are met:1.3.1 The new site is within 2000 m laterally and 500 m vertically.1.3.2 The change of pressure during the previous 10 min has been less than 20 Pa.The pressure, P2 at Site 2 is a function of the known pressure P1 at Site 1, the algebraic difference in height above sea level, h1 −  h2, and the average absolute temperature in the space between. The functional relationship between P1 and P2 is shown in 10.2. The difference between P1 and P2 for each 1 m of difference between h1 and h2 is given in Table 1 and 10.4 for selected values of P1 and average temperature.1.4 Atmospheric pressure varies with time. These test methods provide instantaneous values only.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 and health practices and determine the applicability of regulatory limitations prior to use. Specific safety precautionary statements are given in Section 7.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 The accurate measurement of pH in atmospheric wet deposition is an essential and critically important component in the monitoring of atmospheric wet deposition for trends in the acidity and overall air quality. Atmospheric wet deposition is, in general, a low ionic strength, unbuffered solution. Special precautions, as detailed in this test method, are necessary to ensure accurate pH measurements (1).3 Special emphasis must be placed on minimizing the effect of the residual liquid junction potential bias.5.2 This test method is applicable only to the measurement of pH in atmospheric wet deposition. Its use in other applications may result in inaccuracies.5.3 Fig. 1 provides a frequency distribution of precipitation pH values measured in conjunction with a national monitoring program within the United States. These data are an indication of the range of pH values common to atmospheric wet deposition.FIG. 1 Frequency Distribution of Measured Laboratory pH of Atmospheric Wet Deposition From the 1984 National Atmospheric Deposition Program (NADP)/National Trends Network (NTN)1.1 This test method is applicable to the determination of pH in atmospheric wet deposition samples by electrometric measurement using either a pH half cell with a reference probe or a combination electrode as the sensor.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 Warning—Mercury has been designated by many regulatory agencies as a hazardous material that can cause serious medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Safety Data Sheet (SDS) for additional information. Users should be aware that selling mercury or mercury-containing products into your state or country may be prohibited by law.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

5.1 Guidance is provided on designing model evaluation performance procedures and on the difficulties that arise in statistical evaluation of model performance caused by the stochastic nature of dispersion in the atmosphere. It is recognized there are examples in the literature where, knowingly or unknowingly, models were evaluated on their ability to describe something which they were never intended to characterize. This guide is attempting to heighten awareness, and thereby, to reduce the number of “unknowing” comparisons. A goal of this guide is to stimulate development and testing of evaluation procedures that accommodate the effects of natural variability. A technique is illustrated to provide information from which subsequent evaluation and standardization can be derived.1.1 This guide provides techniques that are useful for the comparison of modeled air concentrations with observed field data. Such comparisons provide a means for assessing a model's performance, for example, bias and precision or uncertainty, relative to other candidate models. Methodologies for such comparisons are yet evolving; hence, modifications will occur in the statistical tests and procedures and data analysis as work progresses in this area. Until the interested parties agree upon standard testing protocols, differences in approach will occur. This guide describes a framework, or philosophical context, within which one determines whether a model's performance is significantly different from other candidate models. It is suggested that the first step should be to determine which model's estimates are closest on average to the observations, and the second step would then test whether the differences seen in the performance of the other models are significantly different from the model chosen in the first step. An example procedure is provided in Appendix X1 to illustrate an existing approach for a particular evaluation goal. This example is not intended to inhibit alternative approaches or techniques that will produce equivalent or superior results. As discussed in Section 6, statistical evaluation of model performance is viewed as part of a larger process that collectively is referred to as model evaluation.1.2 This guide has been designed with flexibility to allow expansion to address various characterizations of atmospheric dispersion, which might involve dose or concentration fluctuations, to allow development of application-specific evaluation schemes, and to allow use of various statistical comparison metrics. No assumptions are made regarding the manner in which the models characterize the dispersion.1.3 The focus of this guide is on end results, that is, the accuracy of model predictions and the discernment of whether differences seen between models are significant, rather than operational details such as the ease of model implementation or the time required for model calculations to be performed.1.4 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This guide cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This guide 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 it be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this guide means only that the document has been approved through the ASTM consensus process.1.5 This standard applies to gaussian plume models; it may not be applicable to non-point sources, heavy gas models from evaporation from pool (for example, liquid spills), as well as near-field receptors.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this guide.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

4.1 Erratic operation or malfunction of a membrane switch resulting from changes in the specified switch characteristics,4.2 Rupture, implosion or explosion of seals due to pressure variations,4.3 Change in physical or chemical properties due to pressure differentiations, and4.4 Delaminations of a membrane switch may occur due to pressure variations.1.1 This test method covers a procedure for exposing a membrane switch to variations in atmospheric pressure. It can be used to determine the effects of pressure variations on chemical and mechanical properties and functional characteristics of the switch.

定价： 0元 / 折扣价： 0 元

3.1 This test method is capable of generating quantitative values of atmospheric chloride deposition specifying milligrams of chloride ions per square metre per day (or other units derived from such values).NOTE 1: Chlorides in the atmosphere exist as a suspension of liquid droplets or solid particles. They are transported to solid surfaces by gravity, wind, or brownian motions. These transport mechanisms are direction-sensitive so that a vertical cylinder will not necessarily receive the same flux as a horizontal plate, or objects with different sizes and orientations. Therefore, the use of this approach to provide an indication of the deposition of chlorides on objects in atmospheric exposures may not be quantitatively accurate; however, this technique has been successful in classifying the severity of exposure in a variety of marine locations.3.2 The sites where samples are to be taken and the sampling time periods should be established. A continuous program of monthly or 30-day exposures is recommended for site characterization. Seasonal monitoring may be performed if there are specific periods of interest.1.1 This test method covers a wet candle device and its use in measuring atmospheric chloride deposition (amount of chloride salts deposited from the atmosphere on a given area per unit time).1.2 Data on atmospheric chloride deposition can be useful in classifying the corrosivity of a specific area, such as an atmospheric test site. Caution must be exercised, however, to take into consideration the season because airborne chlorides vary widely between seasons.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： 515元 / 折扣价： 438 元 加购物车