定价： 590元 / 折扣价： 502 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

This specification states the requirements for sound sources used for measuring the speech privacy between open offices or for measuring the laboratory performance of acoustical components. The sound source shall be a loudspeaker enclosed in a box that has a maximum dimension of 0.30 m (1 ft) on a side, to reduce spurious sound reflections. The measurements shall be carried out in a free sound field. The measurement microphone, amplifier, and level meter used to measure sound pressure levels shall satisfy the requirements prescribed. When the sound source is driven with the qualification signal, the sound output shall be adequate to maintain one-third octave-band sound pressure levels at least 10 dB above the corresponding background noise in each band at each measurement location. The directivity of the sound source shall be verified by driving the source with the qualification signal and measuring the sound pressure levels at measurement points.1.1 This specification states the requirements for sound sources used for measuring the speech privacy between open offices and for measuring the laboratory performance of acoustical components (see Test Methods E1111 and E1130).1.2 The sound source shall be a loudspeaker located in an enclosure driven with an appropriate test signal.1.3 This specification describes the sound source and method of qualifying it using a special qualification signal. Test signals required by open office test methods may differ.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 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

1.1 This guide covers the preparation of a formal plan for measurement of outdoor sound levels. A documented, detailed plan is highly desirable and useful for major environmental noise studies requiring measurements at several locations over a long period. This guide is intended primarily for use in such cases. Many simple measurements can be made without extensive prior planning or documentation. It is recommended that persons or organizations routinely performing such measurements draft and use a brief generic plan based on, but not referencing, this guide. Note 1The extent of planning and plan documentation should be consistent with the budget and needs of the project. In a large measurement program it is possible that use of a formal measurement plan could result in cost savings greater than the cost of preparing the plan. A formal documented plan can be prepared for even the simplest measurement. However, on a small project, the cost of preparation of a formal plan may not be cost effective. In such cases, plan documentation could be limited to inclusion in the final report.1.1.1 This guide addresses the following aspects of outdoor sound level measurements:1.1.2 Test Method E 1503 for Conducting Outdoor Sound Measurements Using a Digital Statistical Analysis System addresses listed aspects of outdoor sound level measurements for situations that are normally encountered. Many other formal and informal practices also address most of these issues. However, there is sometimes a need to depart from the normal methods in order to accommodate a special situation or a regulatory requirement. This guide provides options that are technically correct for specific situations, and provides the information needed for selecting appropriate options.1.1.3 This guide may be used when planning a program for obtaining either a single measurement set of sound level data or multiple sets of data, as well as related supporting data.1.2 Measurements that may be planned using this guide include, but are not limited, to the following:1.2.1 Characterization of the acoustical environment of a site.1.2.2 Characterization of the sound emissions of a specific sound source that exhibits a temporal variation in sound output.1.2.3 Measurement of low-frequency sound (infra-sound) is included because it is sometimes implicated in driving structural vibration that translates to audible interior sound.1.2.4 Measurement of impulsive sound and sound with significant tonal content.1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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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4.1 Situations for which outdoor sound level data are required include, but are not limited to, comparison of sound levels with criteria or regulatory limits.4.2 This guide provides information to (1) measure outdoor sound level in the vicinity of outdoor fixed noise sources, and (2) document other observations necessary for the measurements. This guide provides a standard procedure for a trained acoustical professional that will produce results and documentation which are consistent with the purposes cited in 1.1.1 – 1.1.5.4.3 These sound measurements should be performed by or under the direction of a person experienced in the measurement and analysis of outdoor sound, and who is familiar with the use of the required equipment and techniques.4.4 This guide can be used by individuals, regulatory agencies, or others as a measurement guide to collect data on the sound level received from a fixed source within the constraints cited in Section 8 and Appendix X1 and Appendix X2.4.5 This guide can be used to establish compliance or noncompliance at the time, distance, and conditions during which the data were obtained. However, this guide is only a measurement procedure and does not address the problem of projecting the acquired data outside those conditions, other times of day, other distances, or comparison with specific criteria. In particular, for a given sound source level, distant noise levels will often be found to be greater at night than during the day.1.1 This guide covers the measurement of outdoor sound due to a fixed sound source such as a siren, stationary pump, power plant, or music amphitheater. Procedures characterize the location, sound level, spectral content, and temporal characteristics of that sound source at the time of measurement. Users should be aware that wind and temperature gradients can cause significant variations in sound levels beyond 300 m. With appropriate caution, the use of measurements resulting from this guide include but are not limited to:1.1.1 Assessing compliance with applicable regulations,1.1.2 Monitoring the effectiveness of a noise reduction plan,1.1.3 Verifying the effectiveness of measures for mitigation of noise impact,1.1.4 Validating sound prediction models, and1.1.5 Obtaining source data for use in sound prediction models.1.2 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.1.3 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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4.1 The sound absorption of a material that covers a flat surface depends not only on the physical properties of the material but also on the way in which the material is mounted over the surface. The mountings specified in these practices are intended to simulate in the laboratory conditions that exist in normal use.4.2 Some of the specified mountings require special fixtures or minor deviations from normal practice. These fixtures or deviations are to be used only during laboratory tests and should not be specified for practical installations. They are noted in the specifications for the mountings in question by the phrase “for laboratory testing only.”4.3 Test reports may refer to these mountings by type designation instead of providing a detailed description of the mounting used.1.1 These practices cover test specimen mountings to be used during sound absorption tests performed in accordance with Test Method C423.1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered 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： 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

定价： 515元 / 折扣价： 438 元 加购物车

4.1 This test method deals with methods and techniques which are well defined and which are understood by a trained acoustical professional. This test method has been prepared to provide a standard methodology which, when followed, will produce results which are consistent with requirements of government and industry, and which can be validated using information gathered and documented in the course of the measurement program.4.2 There are numerous situations for which outdoor sound level data are required. These include, but are not limited to the following:4.2.1 Documentation of sound levels before the introduction of a new sound source as a reference for assessment of the noise impact caused by a proposed facility and associated activities,4.2.2 Comparison of sound levels with and without a specific source (for example, assessment of the impact of an existing source), and4.2.3 Comparison of sound levels with criteria or regulatory limits (for example, indication of exceedance of criteria or non-compliance with laws).4.3 This test method provides a means for operating a sound analysis system which incorporates digital circuits for processing and storing sound level data, documenting conditions under which the measurements were performed, and reporting the results.4.4 This test method provides the user with information to (1) perform and document statistical analysis of outdoor sound level over specific time periods at specified places, and (2) make and document the physical observations necessary to qualify the measurements.4.5 This test method can be used by individuals, regulatory agencies, or others as a measurement method to collect acoustical data for many common situations. The data are collected in a format determined by the capabilities of the equipment, equipment operational options selected, and by post-processing options available.4.6 The user is cautioned that there are many factors that can strongly influence the results obtained during measurement of outdoor sound levels and that this test method is not intended to supplant the experience and judgment of experts in the field of acoustics. This test method is intended to facilitate communication between sound measurement professionals and individuals who are responsible for administering regulations, or are otherwise involved in decisions involving sound measurements. Measurements shall be performed only under the direction of people who are experienced in the measurement and analysis of outdoor sound, and who are thoroughly familiar with the use of the equipment and techniques involved.4.7 This test method is only a measurement procedure and, as such, does not address the methods of comparison of the acquired data with specific criteria. No procedures are provided within this test method for estimating the influences of two or more simultaneously measured sounds. This test method can be used, with an appropriate plan, in establishing compliance when the measured data are below a specified limit, or conversely, establishing noncompliance when any of the data are above a specified limit.1.1 This test method covers the measurement of outdoor sound levels at specific locations using a digital statistical sound analysis system and a formal measurement plan.1.1.1 This test method provides basic requirements for obtaining either a single set of data or multiple sets of related data. However, because there are numerous circumstances and varied objectives requiring multiple sets of data, the test method does not address planning of the measurement program.1.2 The use of results of measurements performed using this test method include, but are not limited to, the following:1.2.1 To characterize the acoustical environment of a site,1.2.2 To characterize the sound emissions of a specific sound source which exhibits a temporal variation in sound output, and1.2.3 To monitor the effectiveness of a noise impact mitigation plan.1.3 This test method is intended to be used in conjunction with a measurement plan that references this test method. Changes or additions to the provisions of this test method shall be clearly stated in the plan.1.3.1 In the event it is necessary, for example, because of time constraints, to conduct measurements without first formalizing a plan, this test method can be used if an operator/observer whose qualifications are satisfactory to both the performing organization and the client is present at all times during the measurements and who complies, to the extent possible, with all the applicable requirements of this test method, including record keeping.1.4 The data obtained using this test method enable comparison of sound level data with appropriate criteria.1.4.1 The data obtained with this test method can be used in the derivation of loudness levels provided the necessary requirements regarding sample duration and signal bandwidth are observed in collecting the data. It is recommended that a specialist in the area of loudness evaluation be consulted in preparing a plan for measurements intended to produce data which will be used for this purpose.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： 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