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4.1 This practice is intended for use in determining the sample size required to estimate, with specified precision, a measure of quality of a lot or process. The practice applies when quality is expressed as either the lot average for a given property, or as the lot fraction not conforming to prescribed standards. The level of a characteristic may often be taken as an indication of the quality of a material. If so, an estimate of the average value of that characteristic or of the fraction of the observed values that do not conform to a specification for that characteristic becomes a measure of quality with respect to that characteristic. This practice is intended for use in determining the sample size required to estimate, with specified precision, such a measure of the quality of a lot or process either as an average value or as a fraction not conforming to a specified value.AbstractThis practice covers simple methods for calculating how many units to include in a random sample in order to estimate with a specified precision, a measure of quality for all the units of a lot of material or produced by a process. It also treats the common situation where the sampling units can be considered to exhibit a single source of variability; it does not treat multi-level sources of variability.1.1 This practice covers simple methods for calculating how many units to include in a random sample in order to estimate with a specified precision, a measure of quality for all the units of a lot of material, or produced by a process. This practice will clearly indicate the sample size required to estimate the average value of some property or the fraction of nonconforming items produced by a production process during the time interval covered by the random sample. If the process is not in a state of statistical control, the result will not have predictive value for immediate (future) production. The practice treats the common situation where the sampling units can be considered to exhibit a single (overall) source of variability; it does not treat multi-level sources of variability.1.2 The system of units for this standard is not specified. Dimensional quantities in the standard are presented only as illustrations of calculation methods. The examples are not binding on products or test methods treated.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.

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This specification covers annular ball bearings intended primarily for use in instrument and precision rotating components. Annular ball bearings for instrument and precision rotating components shall be of the following types, as specified: type I - deep groove, unflanged; type II - deep groove, flanged; type III - deep groove, unflanged, inner ring extended; type IV - deep groove, flanged, inner ring extended; type V - angular contact, unflanged, nonseparable, and counterbored outer ring; type VI - angular contact, flanged, nonseparable, and counterbored outer ring on flange side; type VII - angular contact, unflanged, separable, and stepped inner ring; type VIII - angular contact, flanged, separable, and stepped inner ring; type IX - angular contact, unflanged, nonseparable, and stepped inner ring. Materials inspection, passivation test, visual inspection, dimensional inspections, radial internal clearance, torque test, ball quality inspection, hardness test, surface roughness test, dimensional stability test, lubricant inspection, and calibration classification inspection shall be performed to meet the requirements prescribed.1.1 This specification covers annular ball bearings intended primarily for use in instrument and precision rotating components. Instrument and precision ball bearings should meet tolerances specified in ABMA Standard 12.2, Instrument Ball Bearings Inch Design for Classes ABEC 5P and 7P.1.2 Intended Use—Ball bearings defined by this specification are intended for use in critical components of instrument systems. Such components range from air circulating blowers and drive motors through precision gear trains, gyro gimbals, and pickoffs to rate integrating spin-motors.1.3 The specification contains many of the requirements of MIL-B-81793, which was originally developed by the Department of Defense and maintained by the Naval Air Systems Command (Navy-AS) in Lakehurst, NJ. The following government activity codes may be found in the Department of Defense, Standardization Directory SD-1.2Preparing activity Custodians Review activitiesNavy - AS Army - AT Army-AV  Navy - AS Navy - MC, SH  Air Force - 99 Air Force–84  DLA - GS  1.4 Classification—Annular ball bearings for instrument and precision rotating components shall be of the following types, as specified:1.4.1 Type I—Annular ball bearing, for instruments and precision rotating components, deep groove, unflanged; (See Annex A1 – Annex A4)1.4.2 Type II—Annular ball bearing, for instruments and precision rotating components, deep groove, flanged; (See Annex A5 – Annex A8)1.4.3 Type III—Annular ball bearing, for instruments and precision rotating components, deep groove, unflanged, inner ring extended; (See Annex A9 – Annex A12)1.4.4 Type IV—Annular ball bearing, for instruments and precision rotating components, deep groove, flanged, inner ring extended; (See Annex A13 – Annex A16)1.4.5 Type V—Annular ball bearing, for instruments and precision rotating components, angular contact, unflanged, nonseparable, and counterbored outer ring; (See Annex A17 – Annex A20)1.4.6 Type VI—Annular ball bearing, for instruments and precision rotating components, angular contact, flanged, nonseparable, and counterbored outer ring on flange side; (See Annex A21 – Annex A24)1.4.7 Type VII—Annular ball bearing, for instruments and precision rotating components, angular contact, unflanged, separable, and stepped inner ring; (See Annex A25 – Annex A28)1.4.8 Type VIII—Annular ball bearing, for instruments and precision rotating components, angular contact, flanged, separable, and stepped inner ring; (See Annex A29 – Annex A32)1.4.9 Type IX—Annular ball bearing, for instruments and precision rotating components, angular contact, unflanged, nonseparable, and stepped inner ring. (See Annex A33 – Annex A36)1.5 Inch-Pound Specification—This specification covers only the inch-pound bearings.1.5.1 The values stated in inch-pound 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.

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4.1 Each test method has a limited precision. Even if a test is performed as carefully and as correctly as possible on a material which is as homogeneous as can be obtained, the test will still vary from one to another. A widely used measure of the variation of the test results from a test method is the standard deviation (σ). In an ASTM standard test method, the standard deviation of the test method can be found in the Precision and Bias statement for the test. The “Blue Book,” Form and Style for ASTM Standards, requires that all test methods include Precision and Bias statements. Practices C670 and C802 provide guidance for determination of these values.4.2 If the precision of a test method is low and the precision of the test has not been properly considered in a material specification, a uniform material with the right quality may still be rejected most of the time because of the wide variation of the test results. In order to have rational specification limits, the precision of the test used should be properly included in a specification.4.3 This practice provides a guideline for proper inclusion of precision of the test method in a rational specification.1.1 This practice covers a method of determining rational specification limits by inclusion of the precision of the test method used in the specification.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 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of 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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4.1 To describe the uncertainties of a standard test method, precision and bias statements are required.3 The formulation of these statements has been addressed from time to time, and at least two standards practices (Practices E177 and E691) have been issued. The 1986 Compilation of ASTM Standard Definitions (6)4 devotes several pages to these terms. This guide should not be used in cases where small numbers of test results do not support statistical normality. 4.2 The intent of this guide is to help analysts prepare and interpret precision and bias statements. It is essential that, when the terms are used, their meaning should be clear and easily understood. 4.3 Appendix X1 provides the theoretical foundation for precision and bias concepts and Practice E691 addresses the problem of sources of variation. To illustrate the interplay between sources of variation and formulation of precision and bias statements, a hypothetical data set is analyzed in Appendix X2. This example shows that depending on how the data was collected, different precision and bias statements are possible. Reference to this example will be found throughout this guide. 4.4 There has been much debate inside and outside the statistical community on the exact meaning of some statistical terms. Thus, following a number of the terms in Section 3 is a list of several ways in which that term has been used. This listing is not meant to indicate that these meanings are equivalent or equally acceptable. The purpose here is more to encourage clear definition of terms used than to take sides. For example, use of the term systematic error is discouraged by some. If it is to be used, the reader should be told exactly what is meant in the particular circumstance. 4.5 This guide is intended as an aid to understanding the statistical concepts used in precision and bias statements. There is no intention that this be a self-contained introduction to statistics. Since many analysts have no formal statistical training, it is advised that a trained statistician be consulted for further clarification if necessary. 1.1 This guide covers terminology useful for the preparation and interpretation of precision and bias statements. This guide does not recommend a specific error model or statistical method. It provides awareness of terminology and approaches and options to use for precision and bias statements. 1.2 In formulating precision and bias statements, it is important to understand the statistical concepts involved and to identify the major sources of variation that affect results. Appendix X1 provides a brief summary of these concepts. 1.3 To illustrate the statistical concepts and to demonstrate some sources of variation, a hypothetical data set has been analyzed in Appendix X2. Reference to this example is made throughout this guide. 1.4 It is difficult and at times impossible to ship nuclear materials for interlaboratory testing. Thus, precision statements for test methods relating to nuclear materials will ordinarily reflect only within-laboratory variation. 1.5 No units are used in this statistical analysis. 1.6 This guide does not involve the use of materials, operations, or equipment and does not address any risk associated. 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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3.1 This test method covers the determination of the change of resistance with temperature for precision resistors and shunts made from sheet materials.3.2 Materials normally used in the temperature range from 0 to 80°C may be tested using this test method.1.1 This test method covers the determination of the change of resistance with temperature of sheet materials used for shunts and precision resistors for electrical apparatus. It is applicable to materials normally used in the temperature range of from 0 to 80°C.1.2 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate.1.3 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental practices, and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 The objective of this standard is to provide guidelines to Committee D22 for the evaluation of the precision and bias, or both, of ASTM standard methods and practices at the time of their development. Such an evaluation is necessary to assure that a cross section of interested laboratories could perform the test and achieve satisfactory results, using the method as written. It also provides guidance to the user as to what levels of precision and accuracy may be expected in such usage.5.2 The write-up of the method describes the media for which the test method is believed to be appropriate. The collaborative test corroborates the write-up within the limitations of the test design. A collaborative test can only use representative media so that universal applicability cannot be implied from the results.5.3 The fundamental assumption of the collaborative test is that the media tested, the concentrations used, and the participating laboratories are representative and provide a fair evaluation of the scope and applicability of the test method as written.1.1 This standard provides guidance to task groups of Committee D22 on Sampling and Analysis of Atmospheres in planning and conducting collaborative testing of candidate methods.1.2 It is intended for use with other ASTM practices for the determination of precision and bias.1.3 It is applicable to most manual and automated methods and to most components of monitoring systems. It is recognized that the evaluation of monitoring systems may provide special problems. Practice D3249 should be considered for general guidance in this respect.1.4 It is directly applicable to chemical methods and in principle to most physical methods, sampling methods, and calibration procedures.1.5 The processes described are for the general validation of methods of test. A user has the obligation and responsibility to validate any method it uses for a specific application and to demonstrate its own competence in the use of validated methods.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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4.1 The purpose of this test method is to provide a test method for the evaluation of less lethal impact rounds used by law enforcement, corrections, and other public safety officers.4.2 This test method may be used by suppliers, certification bodies, testing laboratories, research and development organizations, and others assessing the performance of less lethal impact rounds.4.3 This test method may be used by purchasers in their evaluation of products to meet their needs and requirements.1.1 This test method addresses direct-fire, single-projectile less lethal impact rounds used by public safety officers, including law enforcement, corrections, and others.1.2 This test method addresses both blunt impact rounds and payload delivery rounds.1.2.1 This test method is limited to direct-fire, single-projectile rounds and excludes skip-fire rounds or multiple-projectile rounds.1.3 This test method is used to measure velocity and determine precision and impact energy for a round.1.4 A specification is under development by ASTM that addresses the safety of targeted individuals during deployment of less lethal impact rounds. That specification will reference this test method.1.5 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.1.6 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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3.1 The purpose of an interlaboratory evaluation, as defined in this guide, is to determine the variability of results obtained in different laboratories on equivalent equipment using a prescribed test method.3.2 The definitions of statistical terms used in this guide are contained in Terminology E456.1.1 This guide covers a simplified statistical procedure for planning and conducting interlaboratory evaluations of test methods.1.2 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 The heat of combustion is a measure of the energy available from a fuel. A knowledge of this value is essential when considering the thermal efficiency of equipment for producing either power or heat.5.2 The mass heat of combustion, that is, the heat of combustion per unit mass of fuel, is measured by this procedure. Its magnitude is particularly important to weight-limited vehicles such as airplanes, surface effect vehicles, and hydrofoils as the distance such craft can travel on a given weight of fuel is a direct function of the fuel's mass heat of combustion and its density.5.3 The volumetric heat of combustion, that is, the heat of combustion per unit volume of fuel, can be calculated by multiplying the mass heat of combustion by the density of the fuel (mass per unit volume). The volumetric heat of combustion, rather than the mass heat of combustion, is important to volume-limited craft such as automobiles and ships, as it is directly related to the distance traveled between refuelings.1.1 This test method covers the determination of the heat of combustion of hydrocarbon fuels. It is designed specifically for use with aviation turbine fuels when the permissible difference between duplicate determinations is of the order of 0.2 %. It can be used for a wide range of volatile and nonvolatile materials where slightly greater differences in precision can be tolerated.1.2 In order to attain this precision, strict adherence to all details of the procedure is essential since the error contributed by each individual measurement that affects the precision shall be kept below 0.04 %, insofar as possible.1.3 Under normal conditions, this test method is directly applicable to such fuels as gasolines, kerosines, Nos. 1 and 2 fuel oil, Nos. 1-D and 2-D diesel fuel, and Nos. 0-GT, 1-GT, and 2-GT gas turbine fuels.1.4 Through the improvement of the calorimeter controls and temperature measurements, the precision is improved over that of Test Method D240.1.5 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. For specific warning statements, see Section 7, 10.6, A1.7.1, and Annex A3.1.7 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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