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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

定价： 590元 / 折扣价： 502 元 加购物车

5.1 Appropriate application of this practice should result in an estimate of the test-method’s uncertainty (at any concentration within the working range), which can be compared with data-quality objectives to see if the uncertainty is acceptable.5.2 With data sets that compare recovered concentration with true concentration, the resulting regression plot allows the correction of the recovery data to true values. Reporting of such corrections is at the discretion of the user.5.3 This practice should be used to estimate the measurement uncertainty for any application of a test method where measurement uncertainty is important to data use.1.1 This practice establishes a standard for computing the measurement uncertainty for applicable test methods in Committee D19 on Water. The practice does not provide a single-point estimate for the entire working range, but rather relates the uncertainty to concentration. The statistical technique of regression is employed during data analysis.1.2 Applicable test methods are those whose results come from regression-based methods and whose data are intra-laboratory (not inter-laboratory data, such as result from round-robin studies). For each analysis conducted using such a method, it is assumed that a fixed, reproducible amount of sample is introduced.1.3 Calculation of the measurement uncertainty involves the analysis of data collected to help characterize the analytical method over an appropriate concentration range. Example sources of data include: (1) calibration studies (which may or may not be conducted in pure solvent), (2) recovery studies (which typically are conducted in matrix and include all sample-preparation steps), and (3) collections of data obtained as part of the method’s ongoing Quality Control program. Use of multiple instruments, multiple operators, or both, and field-sampling protocols may or may not be reflected in the data.1.4 In any designed study whose data are to be used to calculate method uncertainty, the user should think carefully about what the study is trying to accomplish and much variation should be incorporated into the study. General guidance on designing studies (for example, calibration, recovery) is given in Appendix X1. Detailed guidelines on sources of variation are outside the scope of this practice, but general points to consider are included in Appendix X2, which is not intended to be exhaustive. With any study, the user must think carefully about the factors involved with conducting the analysis, and must realize that the computed measurement uncertainty will reflect the quality of the input data.1.5 Associated with the measurement uncertainty is a user-chosen level of statistical confidence.1.6 At any concentration in the working range, the measurement uncertainty is plus-or-minus the half-width of the prediction interval associated with the regression line.1.7 It is assumed that the user has access to a statistical software package for performing regression. A statistician should be consulted if assistance is needed in selecting such a program.1.8 A statistician also should be consulted if data transformations are being considered.1.9 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.1.10 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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4.1 Environmental site characterization projects almost always require information regarding subsurface soil stratigraphy and hydraulic parameters related to groundwater flow rate and direction. Soil stratigraphy often is determined by various drilling procedures and interpreting the data collected on borehole logs. The electronic piezocone penetrometer test is another means of determining soil stratigraphy that may be faster, less expensive, and provide greater resolution of the soil units than conventional drilling and sampling methods. For environmental site characterization applications, the electronic piezocone also has the additional advantage of not generating contaminated cuttings that may present other disposal problems (2, 3, 4, 5, 6, 7, 8, 9, 10). Investigators may obtain soil samples from adjacent borings for correlation purposes, but prior information or experience in the same area may preclude the need for borings (11). Most cone penetrometer rigs are equipped with direct push soil samplers (Guide D6282/D6282M) that can be used to confirm soil types.4.2 The electronic piezocone penetration test is an in situ investigation method involving:4.2.1 Pushing an electronically instrumented probe into the ground (see Fig. 1 for a diagram of a typical cone penetrometer). The position of the pore pressure element may vary but is typically located in the u2 position, as shown in Fig. 1 (Test Method D5778).4.2.3.3 Robertson proposed the following equations estimating k from Ic and shown on Fig. 4  (11). These equations are used for some cone penetration testing commercial software for estimates of k based on normalized soil behavior type. However, as shown on Tables 1 and 2, the values estimated from Ic are not very accurate for example, the estimated k value may range over two orders of magnitude.FIG. 4 Proposed Relationship Between Ic and Normalized Soil Behavior Type and Estimated Soil Permeability, k (Robertson (1))4.3 When attempting to retrieve a soil gas or water sample, it is advantageous to know where the bearing zones (permeable zones) are located. Although soil gas and water can be retrieved from sediments with low hydraulic conductivity, the length of time required usually makes it impractical. Soil gas and water samples can be retrieved much faster from permeable zones, such as sands. The cone penetrometer tip and friction data generally can distinguish between lower and higher permeability zones less than 0.3 m [1 ft] very accurately.4.4 The electronic cone penetrometer test is used in a variety of soil types. Lightweight equipment with reaction weights of less than 10 tons generally are limited to soils with relatively small grain sizes. Typical depths obtained are 20 to 40 m [60 to 120 ft], but depths to over 70 m [200 ft] with heavier equipment weighing 20 tons or more are not uncommon. Since penetration is a direct result of vertical forces and does not include rotation or drilling, it cannot be utilized in rock or heavily cemented soils. Depth capabilities are a function of many factors (D5778).4.5 Pore Pressure Data: 4.5.1 Excess pore water pressure data often are used in environmental site characterization projects to identify thin soil layers that will either be aquifers or aquitards. The pore pressure channel often can detect these thin layers even if they are less than 20 mm [1 in.] thick.4.5.2 Excess pore water pressure data taken during push are used to provide an indication of relative hydraulic conductivity. Excess pore water pressure is generated during an electronic cone penetrometer test. Generally, high excess pore water pressure indicates the presence of aquitards (clays), and low excess pore water pressure indicates the presence of aquifers (sands). This is not always the case, however. For example, some silty sands and over-consolidated soils generate negative pore pressures if monitored above the shoulder of the cone tip. See Fig. 1. The balance of the data, therefore, also must be evaluated. There have been methods proposed to estimate hydraulic conductivity from dynamic excess pore water pressure measurements (12, 13, 14).4.5.3 Dissipation Tests: 4.5.3.1 In general, since the groundwater flows primarily through sands and not clays, modeling the flow through the sands is most critical. The pore pressure data also can be monitored with the sounding halted. This is called a pore pressure dissipation test. A rapidly dissipating pore pressure indicates the presence of an aquifer while a very slow dissipation indicates the presence of an aquitard. Fig. 5 shows a typical dissipation test showing the t50 determined by waiting for 50 % of the highest pressure registered to dissipate. In some soils there can first be a lag before the peak pore pressure occurs. This example also shows that sufficient time was reached to allow the pore pressure to reach full equalization.FIG. 5 Example Dissipation Test Showing t50 Determination and Equalization of Pore Pressure (Robertson (2))4.5.3.2 Fig. 6 shows one proposed relationship between t50 dissipation time and horizontal, hydraulic conductivity reported by Robertson (2, 11). This chart uses a tip resistance normalized for overburden stresses in the ground. This requires the estimation of the wet and saturated density of the soil and estimated water table location (2). The data points on the chart are laboratory test data from correlated samples. Figure 6 is developed for 10 cm2 diameter cones and a correction factor is required for 15 cm2 cones (multiply k values by factor of 1.5) (2).FIG. 6 Relationship Between CPTu t50 (in minutes) and Soil Hydraulic Conductivity (k) and Normalized Cone Resistance, Qtn (After Robertson (2, 11, 15))4.5.3.3 Included in Fig. 6 is a proposed relationship between dissipation time, soil type, and hydraulic conductivity proposed by Parez and Fauriel (15). This relationship is used in 4.5.3.4 by the high resolution piezocone (HRP) (16) for dissipation tests in sands.4.5.3.4 A pore pressure decay in a clean sand is almost instantaneous. The hydraulic conductivity, therefore, is very difficult to measure in a sand with a cone penetrometer. As a result, until recently the cone penetrometer was not used very often for measuring the hydraulic conductivity of sands in environmental applications. The HRP cone uses special high resolution hardware and software to allow for high resolution data collection even in rapidly dissipating sand formations (16, 17), although recent experience indicates that this might be limited to hydraulic conductivity values less than 10-3 cm/s (18, 19). Partial drainage can also become an issue for cone penetration testing in soils where t50 < 50s and the approximate limits for undrained cone penetration are shown on Fig. 6  (20).4.5.3.5 A thorough study of groundwater flow also includes determining where the water cannot flow. Cone penetrometer pore pressure dissipation tests can be used very effectively to study the hydraulic conductivity of confining units. However, long excessive times for dissipation may not be economical in production CPT. Burns and Mayne (21) have developed methods to model the pore pressure dissipations tests in clays considering the stress history of the clays and can predict k and consolidation characteristics. Their method uses a seismic piezocone to measure the soil stiffness using down-hole shear wave velocity measurements.4.5.3.6 The pore pressure data also can be used to estimate the depth to the water table or identify perched water zones. This is accomplished by allowing the excess pore water pressure to equilibrate and then subtract the appropriate head pressure. Due to high excess pore pressures being generated, typical pore pressure transducers are configured to measure pressures up to 3.5 MPa [500 lbf/in.2] or more. Since transducer accuracy is a function of maximum range, this provides a relative depth to water level accuracy of about ±100 mm [0.5 ft]. Better accuracy can be achieved if the operator allows sufficient time for the transducer to dissipate the heat generated while penetrating dry soil above the water table. Lower pressure transducers are sometimes used just for the purpose of determining the depth to the water table more accurately. For example, a 175-kPa [25-lbf/in.2] transducer would provide accuracy that is better than 10 mm [0.5 in.]. Incorporation of a temperature transducer and appropriate calibration allows for high precision and rapid data collection. Caution must be used, however, to prevent these transducers from being damaged due to a quick rise in excess pressure. Some newer systems allow for large burst pressure protection without hysteresis, which enables users to collect data in highly stratified environments without as much concern for transducer damage.4.5.3.7 When coupled with appropriate models, three dimensional gradient can be derived from final pressure values collected from multiple CPT locations. Once gradient distributions have been derived, and hydraulic conductivity and effective porosity distributions have been generated, seepage velocity distributions can be derived and visualized. This type of information is critical to environmental investigations and remediation design. If contaminant concentration distributions are known, the same software can be used to derive three dimensional distributions of contaminant mass flux.4.6 For a complete description of a typical geotechnical electronic cone penetrometer test, see Test Method D5778.4.7 This practice tests the soil in situ. Soil samples are not obtained. The interpretation of the results from this practice provides estimates of the types of soil penetrated. Onboard CPT single rod soil samplers (D6282/D6282M) are available for short discrete interval soil sampling. Continuous soil cores can be obtained rapidly in a separate location using continuous direct push dual tube samplers (D6282/D6282M). Investigators may obtain soil samples from adjacent locations for correlation purposes, but prior information or experience in the same area may preclude the need for borings for soil samples.4.8 Certain subsurface conditions may prevent cone penetration. Penetration is not possible in hard rock and usually not possible in softer rocks, such as claystones and shales. Coarse particles, such as gravels, cobbles, and boulders may be difficult to penetrate or cause damage to the cone or push rods. Cemented soil zones may be difficult to penetrate depending on the strength and thickness of the layers. If layers are present which prevent direct push from the surface, rotary or percussion drilling methods can be employed to advance a boring through impeding layers to reach testing zones.NOTE 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.Practice D3740 was developed for agencies engaged in the laboratory testing or inspection of soils and rock or both. As such, it is not totally applicable to agencies performing this field practice. However, users of this practice should recognize that the framework of Practice D3740 is appropriate for evaluating the quality of an agency performing this practice. Currently there is no known qualifying national authority that inspects agencies that perform this practice.1.1 The electronic cone penetrometer test often is used to determine subsurface stratigraphy for geotechnical and environmental site characterization purposes (1).2 The geotechnical application of the electronic cone penetrometer test is discussed in detail in Test Method D5778, however, the use of the electronic cone penetrometer test in environmental site characterization applications involves further considerations that are not discussed. For environmental site characterization, it is highly recommended to use the Piezocone (PCPT or CPTu) option in Test Method D5778 so information on hydraulic conductivity and aquifer hydrostatic pressures can be evaluated.1.2 The purpose of this practice is to discuss aspects of the electronic cone penetrometer test that need to be considered when performing tests for environmental site characterization purposes.1.3 The electronic cone penetrometer test for environmental site characterization projects often requires steam cleaning the push rods and grouting the hole. There are numerous ways of cleaning and grouting depending on the scope of the project, local regulations, and corporate preferences. It is beyond the scope of this practice to discuss all of these methods in detail. A detailed explanation of grouting procedures is discussed in Guide D6001.1.4 Cone penetrometer tests are often used to locate aquifer zones for installation of wells (Practice D5092/D5092M, Guide D6274). The cone test may be combined with direct push soil sampling for confirming soil types (Guide D6282/D6282M). Direct push hydraulic injection profiling (Practice D8037/D8037M) is another complementary test for estimating hydraulic conductivity and direct push slug tests (D7242/D7242M) and used for confirming estimates. Cone penetrometers can be equipped with additional sensors for groundwater quality evaluations (Practice D6187). Location of other sensors must conform to requirements of Test Method D5778.1.5 This practice is applicable only at sites where chemical (organic and inorganic) wastes are a concern and is not intended for use at radioactive or mixed (chemical and radioactive) waste sites due to specialized monitoring requirements of drilling equipment.1.6 Units—The values stated in either SI units or in-lb units (presented in brackets) 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. Units for conductivity are either m/s or cm/s depending on the sources cited.1.7 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this 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 practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard 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 this document be applied without consideration of a project's many unique aspects. The word "Standard" in the title means only that the document has been approved through the ASTM consensus process.1.10 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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Ranked set sampling is cost-effective, unbiased, more precise and more representative of the population than simple random sampling under a variety of conditions (1).3Ranked set sampling (RSS) can be used when:4.2.1 The population is likely to have stratification in concentrations of contaminant.4.2.2 There is an auxiliary variable.4.2.3 The auxiliary variable has strong correlation with the primary variable.4.2.4 The auxiliary variable is either quick or inexpensive to measure, relative to the primary variable.This guide provides a ranked set sampling method only under the rule of equal allocation. This guide is intended for those who manage, design, and implement sampling and analysis plans for management of wastes and contaminated media. This guide can be used in conjunction with the DQO process (see Practice D 5792).1.1 This guide describes ranked set sampling, discusses its relative advantages over simple random sampling, and provides examples of potential applications in environmental sampling.1.2 Ranked set sampling is useful and cost-effective when there is an auxiliary variable, which can be inexpensively measured relative to the primary variable, and when the auxiliary variable has correlation with the primary variable. The resultant estimation of the mean concentration is unbiased, more precise than simple random sampling, and more representative of the population under a wide variety of conditions.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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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 Manufacturers of radiant barriers express the performance of their products in terms of the total hemispherical emittance. The purpose of a radiant barrier is to decrease the radiation heat transfer across the attic air space, and hence, to decrease the heat loss or gain through the ceiling below the attic. The amount of decrease in heat flow will depend upon a number of factors, such as weather conditions, amount of mass or reflective insulation in the attic, solar absorptance of the roof, geometry of the attic and roof, and amount and type of attic ventilation. Because of the infinite combinations of these factors, it is not practical to publish data for each possible case.5.2 The calculation of heat loss or gain of a system containing radiant barriers is mathematically complex, and because of the iterative nature of the method, it is best handled by computers.5.3 Computers are now widely available to most producers and consumers of radiant barriers to permit the use of this practice.5.4 The user of this practice may wish to modify the data input to represent accurately the structure. The computer program also may be modified to meet individual needs. Also, additional calculations may be desired, for example, to sum the hourly heat flows in some fashion to obtain estimates of seasonal or annual energy usages. This might be done using the hourly data as inputs to a whole-house model, and by choosing house balance points to use as cutoff points in the summations.1.1 This practice covers the estimation of heat gain or loss through ceilings under attics containing radiant barriers by use of a computer program. The computer program included as an adjunct to this practice provides a calculational procedure for estimating the heat loss or gain through the ceiling under an attic containing a truss or rafter mounted radiant barrier. The program also is applicable to the estimation of heat loss or gain through ceilings under an attic without a radiant barrier. This procedure utilizes hour-by-hour weather data to estimate the hour-by-hour ceiling heat flows. The interior of the house below the ceiling is assumed to be maintained at a constant temperature. At present, the procedure is applicable to sloped-roof attics with rectangular floor plans having an unshaded gabled roof and a horizontal ceiling. It is not applicable to structures with flat roofs, vaulted ceilings, or cathedral ceilings. The calculational accuracy also is limited by the quality of physical property data for the construction materials, principally the insulation and the radiant barrier, and by the quality of the weather data.1.2 Under some circumstances, interactions between radiant barriers and HVAC ducts in attics can have a significant effect on the thermal performance of a building. Ducts are included in an extension of the computer model given in the appendix.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 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 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 Magnitude estimation may be used to measure and compare the intensities of attributes of a wide variety of products.5.2 Magnitude estimation provides a large degree of flexibility for both the experimenter and the assessor. Once trained in magnitude estimation, assessors are generally able to apply their skill to a wide variety of sample types and attributes, with minimal additional training.5.3 Magnitude estimation is not as susceptible to end-effects as interval scaling techniques. These can occur when assessors are not familiar with the entire range of sensations being presented. Under these circumstances, assessors may assign an early sample to a category which is too close to one end of the scale. Subsequently, they may “run out of scale” and be forced to assign perceptually different samples to the same category. This should not occur with magnitude estimation, as, in theory, there are an infinite number of categories.5.4 Magnitude estimation is one frequently used technique that permits the representation of data in terms of Stevens' Power Law.5.5 The disadvantages of magnitude estimation arise primarily from the requirements of the data analysis.5.5.1 Permitting each assessor to choose a different numerical scale may produce significant assessor effects. This disadvantage can be overcome in a number of ways, as follows. The experimenter must choose the approach most appropriate for the circumstances.5.5.1.1 Experiments can be designed such that analysis of variance can be used to remove the assessor effects and interactions.5.5.1.2 Alternatively, assessors can be forced to a common scale, either by training or by use of external reference samples with assigned values (modulus).5.5.1.3 Finally, each assessor's data can be brought to a common scale by one of a variety of normalizing methods.5.5.2 Logarithms must be applied before carrying out data analysis. This becomes problematic if values are near threshold, as a logarithm of zero cannot be taken (see 11.2.1).5.6 Magnitude estimation should be used:5.6.1 When end-effects are a concern, for example when assessors are not familiar with the entire range of sensations being presented.5.6.2 When Stevens' Power Law is to be applied to the data.5.6.3 Generally, in central location testing with assessors trained in the technique. It is not appropriate for home use or mall intercept testing with consumers.5.7 This test method is only meant to be used with assessors who are specifically trained in magnitude estimation. Do not use this method with untrained assessors or untrained consumers.1.1 This test method describes a procedure for the application of unipolar magnitude estimation to the evaluation of the magnitude of sensory attributes. The test method covers procedures for the training of assessors to produce magnitude estimations and statistical evaluation of the estimations.1.2 Magnitude estimation is a psychophysical scaling technique in which assessors assign numeric values to the magnitude of an attribute. The only constraint placed upon the assessor is that the values assigned should conform to a ratio principle. For example, if the attribute seems twice as strong in sample B when compared to sample A, sample B should receive a value which is twice the value assigned to sample A.1.3 The intensity of attributes such as pleasantness, sweetness, saltiness or softness can be evaluated using magnitude estimation.1.4 Magnitude estimation may provide advantages over other scaling methods, particularly when the number of assessors and the time available for training are limited. With approximately 1 h of training, a panel of 15 to 20 naive individuals can produce data of adequate precision and reproducibility. Any additional training that may be required to ensure that the assessors can properly identify the attribute being evaluated is beyond the scope of this test method.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