5.1 This practice describes the maximum transit-rate ratios and depths that can be used for selected isokinetic suspended-sediment sampler/nozzle/container configurations in order to insure isokinetic sampling.5.2 This practice is designed to be used by field personnel collecting whole-water samples from open channel flow.1.1 This practice covers the maximum transit-rate ratios and depths for selected suspended-sediment sampler-nozzle-container configurations.1.2 This practice explains the reasons for limiting the transit-rate ratio and depths that suspended-sediment samplers can be correctly used.1.3 This practice give maximum transit-rate ratios and depths for selected isokinetic suspended-sediment sampler/nozzle/container size for samplers developed by the Federal Interagency Sedimentation Project.1.4 Throughout this practice, a samplers lowering rate is assumed to be equal to its raising rate.1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered 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.

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5.1 Chronic Beryllium Disease (CBD) and Beryllium Sensitization (Be-S) caused by exposure to anthropogenic Beryllium (A-Be) are a continuing health concern in the nuclear and defense industries. The traditional worker protection strategy has been to compare total Be (T-Be) measurements taken in workplaces with appropriate limits or local background Be measurements. That strategy can be ineffective, however, where naturally occurring Be (N-Be) from local soils can be a non-negligible component of the measured T-Be. N-Be is not known to have adverse health effects. This MRM uses the ratio(s) of measurements of Be with measurements of one or more metals found in background materials, but not likely to be in facilities, to predict the amount of N-Be expected in individual samples based on the measurement(s) of the predictor metal(s) in those samples. The measured T-Be can be compared with the predictions to estimate the amount of A-Be present, if any.5.2 In order to use the MRM it is required to identify local sources of N-Be that can be credibly transported into facilities, along with a means of sampling those sources. It would be helpful also to have insight into the metal content of the soils at those sources, to facilitate the identification of candidate predictor metals. Regarding the latter, there are published databases describing the chemistry of surface soils in many regions; however, information found in those databases should be regarded as suggestive, due to the modified sample preparation and analysis methods currently expected to be used because of the need to digest high-fired BeO, one form of A-Be of concern.1.1 This guide describes a general approach to planning investigations in which the goal is to obtain background measurements of naturally occurring Beryllium (N-Be) along with one or more predictor metals in local soils, to be used in predicting the amount of N-Be expected in samples taken for evaluation using the Metal Ratio Method (MRM). Generally, systematic random sampling is recommended, after which the results are interpreted using statistical methods described in this guide.1.2 The total Be (T-Be) measured in evaluation samples can then be compared with the predicted N-Be to estimate the amount of anthropogenic Be (A-Be) present, if any. Several scenarios are discussed in which samples taken and analyzed for T-Be for worker or public protection purposes might include both N-Be and A-Be (see 6.1). This method can allow the N-Be and A-Be components of T-Be measurements to be estimated.1.3 Values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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 document 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 ASTM standard 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 this document be applied without consideration of a project’s many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.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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5.1 Electron multipliers are commonly used in pulse-counting mode to detect ions from magnetic sector mass spectrometers. The electronics used to amplify, detect and count pulses from the electron multipliers always have a characteristic time interval after the detection of a pulse, during which no other pulses can be counted. This characteristic time interval is known as the “dead time.” The dead time has the effect of reducing the measured count rate compared with the “true” count rate.5.2 In order to measure count rates accurately over the entire dynamic range of a pulse counting detector, such as an electron multiplier, the dead time of the entire pulse counting system must be well known. Accurate count rate measurement forms the basis of isotopic ratio measurements as well as elemental abundance determinations.5.3 The procedure described herein has been successfully used to determine the dead time of counting systems on SIMS instruments.6 The accurate determination of the dead time by this method has been a key component of precision isotopic ratio measurements made by SIMS.1.1 This practice provides the Secondary Ion Mass Spectrometry (SIMS) analyst with a method for determining the dead time of the pulse-counting detection systems on the instrument. This practice also allows the analyst to determine whether the apparent dead time is independent of count rate.1.2 This practice is applicable to most types of mass spectrometers that have pulse-counting detectors.1.3 This practice does not describe methods for precise or accurate isotopic ratio measurements.1.4 This practice does not describe methods for the proper operation of pulse counting systems and detectors for mass spectrometry.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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1.1 This test method covers the determination of distribution ratios of chemical species for site-specific geological media by a batch sorption technique. It is a short-term laboratory method primarily intended for ionic species subject to migration in granular porous material, and the application of the results to long-term field behavior is not known. Distribution ratios for radionuclides in selected geomedia are commonly determined for the purpose of assessing potential migratory behavior at waste repositories. This test method is also applicable to studies of intrusion waters and for parametric studies of the effects of variables and of mechanisms which determine the measured distribution ratios.1.2 The values stated in acceptable metric units are to be regarded as the standard.1.3 This standard does not purport to address all of the safety problems, 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 BCR and SIR provide measures of economic performance in a single number that indicates whether a proposed building or building system is preferred over a mutually exclusive alternative that serves as the base for computing the ratio. It may be contrasted with the life-cycle cost (LCC) method that requires two LCC measures to evaluate the economic performance of a building or building system—one for each alternative.5.2 The ratio indicates discounted dollar benefits (or savings) per dollar of discounted costs.5.3 The BCR or SIR can be used to determine if a given building or building system is economic relative to the alternative of not having it.5.4 The BCR or SIR computed on increments of benefits (or savings) and costs can be used to determine if one design or size of a building or system is more economic than another.5.5 The BCR or SIR can be used as an aid to select the economically efficient set of projects among many competing for limited funding. The efficient set of projects will maximize aggregate net benefits or net savings obtainable for the budget.1.1 This practice covers a procedure for calculating and interpreting benefit-to-cost ratios (BCR) and savings-to-investment ratios (SIR) as an aid for making building-related decisions.1.2 A basic premise of the BCR and SIR methods is that future as well as present benefits and costs arising from a decision are important to that decision, and, if measurable in dollars, should be included in calculating the BCR and SIR.1.3 Dollar amounts used to calculate BCR and SIR are all discounted, that is, expressed in time-equivalent dollars, either in present value or uniform annual value terms.1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered 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： 646元 / 折扣价： 550 元 加购物车

This specification covers water well casing pipe and couplings made from thermoplastic materials in standard dimension ratios (SDR), SCH 40 and SCH 80. Well casing is produced in either plain end, belled end, or threaded, and is used for water wells, ground water monitoring, leak detection, recovery systems, dewatering systems, and waste disposal. The well casing pipes, well casing pipe couplings, pipe stiffness and flattening, impact resistance, tup puncture resistance, thread, threaded joints, joint strength, and well screens shall be tested to meet the requirements prescribed.1.1 This specification covers water well casing pipe and couplings made from thermoplastic materials in standard dimension ratios (SDR), SCH 40 and SCH 80.1.2 Specifications are provided for the application of these materials to water well and ground water monitoring applications. Flush threaded joint systems are included for screen and casing used primarily in the construction of ground water monitoring wells (see Practice D5092/D5092M).1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. (See IEEE/ASTM SI 10.)NOTE 1: Certain field conditions may require alternative materials to ensure safe long-term use. The user should consult federal, state, and local codes governing the use of thermoplastic materials for well casing or monitor pipe.NOTE 2: This standard specifies dimensional, performance and test requirements for plumbing and fluid handling applications, but does not address venting of combustion gases.1.4 Although the pipe sizes and SDR values listed in this specification are generally available, numerous other plastic pipes in Schedule 40 and 80 wall, other SDR values and various outside diameters have been used for well casing. Such products are often selected because they fulfill certain needs and Annex A1 includes a list of these Plastic Pipe Well Casing Specials.1.5 The following safety hazards caveat pertains only to the test method portion, Section 6, of this specification: 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： 843元 / 折扣价： 717 元 加购物车