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5.1 The noise reduction of an enclosure is a property of the enclosure, the location of the sound source used to measure noise reduction, and the space in which the enclosure is placed. It is not a property of the enclosure alone, and its measurement under different conditions can be expected to give different results. When the noise reduction is measured in accordance with this test method, the sound source is outside the enclosure and the sound field outside the enclosure approximates a diffuse sound field. Measurements made in accordance with this test method can be expected to be reproducible from one laboratory to another.5.2 The noise reduction measured in accordance with this test method may be used for the following purposes:5.2.1 To rank the order of sound-isolating enclosures according to noise isolation class, NIC.5.2.2 To estimate the highest one-third octave band sound pressure levels that can occur outside the enclosure without exceeding specified sound pressure levels inside the enclosure.5.2.3 To estimate the one-third octave band sound pressure levels that will occur inside the enclosure with specified sound pressure levels outside.5.3 The noise reduction measured in accordance with this test method may not estimate accurately the isolation that the enclosure will provide when it is used to isolate a noise source inside it from the space outside. The user should be cautious when using noise reductions measured by this test method to evaluate enclosures used to enclose noise sources.5.4 Sound-isolating enclosures are frequently made from prefabricated modular panels. The noise reduction measured by this test method applies to the complete enclosure and not to individual panels from which it is made and cannot be used to infer the sound transmission loss of the individual panels.5.5 Specifications for sound-isolating enclosures may include reference to noise reduction and noise isolation class measured in accordance with this test method.1.1 This test method covers the reverberation room measurement of the noise reduction of sound-isolating enclosures.1.2 The noise isolation class may be determined from the noise reduction measured in accordance with this test method.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.

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5.1 To fully understand the effects of a given treatment, five acoustical factors (transmission loss, acceptance, radiation efficiency, absorption, and damping) must be characterized. For example, only knowing the effect of a given treatment on transmission loss will not allow the acoustical designer or engineer to assess its impacts on propagation of vibration (among other effects), which is an important path to consider for large machinery items and propeller excitation.5.2 It is necessary to have a common definition of acoustical performance and test procedure to determine all five acoustical factors for ship’s treatments so that the performance of different treatment types, as well as the same treatment type from different manufacturers, can be compared.5.3 In some cases, particularly for damping treatments, the effect of the treatment will be dependent on the non-treated structure’s material and geometry and other non-acoustic factors such as environmental conditions (that is, temperature). To fully characterize a treatment it may be necessary to test a range of base constructions. For reasons of practicality, convenience, or economy, it may be sufficient to test only one to three constructions to achieve an understanding of the material performance in a range of practical situations. Additional discussion is provided in Annex A1.1.1 This test method covers the laboratory measurement of the acoustical effectiveness of treatments installed on ship bulkheads, decks, and side shells. Measurements are focused on assessing changes in transmission loss, radiation efficiency, and acceptance that occur when treatments are applied. Measurements of changes to absorption and damping are addressed in Appendix X1 and Appendix X2, respectively.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 Any material that is to be installed on a marine division must meet appropriate fire, combustibility, and other applicable SOLAS, USCG, IMO, Navy, or other required non-acoustical standards and specifications. See Appendix X3 for additional information.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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5.1 Use of this guide is intended to provide information on electrochemical noise to monitor corrosion on a continuous basis.5.2 This guide is intended for conducting electrochemical noise measurements, both in the laboratory and in-service environments (36).5.3 This technique is useful in systems in which process upsets or other problems can create corrosive conditions. An early warning of corrosive attack can permit remedial action before significant damage occurs to process equipment (37).5.4 This technique is also useful when inhibitor additions are used to control the corrosion of equipment. The indication of increasing corrosion activity can be used to signal the need for additional inhibitor (38).5.5 Control of corrosion in process equipment requires knowledge of the rate or mechanism of attack on an ongoing basis. This technique can be used to provide such information in a digital format that is easily transferred to computers for analysis (39) .1.1 This guide covers the procedure for conducting online corrosion monitoring of metals by the use of the electrochemical noise technique. Within the limitations described, this technique can be used to detect localized corrosion activity and to estimate corrosion rate on a continuous basis without removal of the monitoring probes from the plant or experimental cell.1.2 This guide presents briefly some generally accepted methods of analyses that are useful in the interpretation of corrosion test results.1.3 This guide does not cover detailed calculations and methods; rather it covers a range of approaches that have found application in corrosion testing.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.

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5.1 This standard defines measurement procedures for estimating the risk of noise-induced hearing loss among users of noise producing equipment. It is applicable to ground vehicles, aircraft, watercraft, and mobile, transportable, and stationary equipment. The primary approach is to separately measure the sound level at operator ear locations for each normal operating condition. These levels can be combined with operational use scenarios and exposure criteria to define noise exposure severity. The data can also be used to define hearing protection requirements or administrative controls to preclude hearing hazards.5.2 The practice has the following limitations:5.2.1 The practice uses field portable measurement equipment.5.2.2 The practice produces data which may be compared with applicable criteria or limits if the limits are in terms of the quantities measured in this standard or which can be calculated from the measured data.1.1 This standard defines noise measurement procedures for estimating the risk of hearing loss among users of noise producing equipment. It is applicable to ground vehicles, aircraft, watercraft, and other mobile, transportable, or stationary equipment.1.2 This standard does not recommend noise exposure limit levels or criteria for any application discussed.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.

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4.1 The rating increases as the impact sound attenuation of the floor ceiling structure increases. The rating can be used by architects, builders, and specification and code authorities for acoustical design purposes in building constructions.4.2 The rating strictly only applies to excitation by the standard tapping machine defined in Test Methods E492 and E1007. It does not deal with low frequency sounds below 100 Hz that are typically generated below lightweight joist floors when they are walked on. Nor does it deal with the squeaking, crunching or rattling sounds that can occur in joist construction when elements in the construction are loose and occupants walk on the floor.4.3 This classification shall only be used with one-third octave band data.1.1 This classification provides a method for determining a rating that can be used to compare the levels of impact noise generated by a standard tapping machine and transmitted through different floor-ceiling assemblies.1.2 The name given to the rating is assigned by the test method that invokes this classification.1.3 This classification is applicable only to one third octave band impact noise data obtained using the standard tapping machine described in Test Methods E492 and E1007.1.4 Test methods that invoke this classification include:1.4.1 Test Method E492 – the single-number rating is called impact insulation class (IIC).1.4.2 Test Method E1007 – the single-number ratings are called apparent impact insulation class (AIIC), impact sound rating (ISR), and normalized impact sound rating (NISR).1.4.3 Test Method E2179 – the single-number rating is called the change in impact insulation class (ΔIIC).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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4.1 Evaluation of Environmental Noise—Environmental noise is evaluated by comparing a measurement or prediction of the noise to one or more criteria. There are many different criteria and ways of measuring and specifying noise, depending on the purpose of the evaluation. Some evaluations are limited to determining compliance with existing regulations or ordinances. Others are done in the absence of such requirements or to supplement regulatory evaluations where the regulations do not address fully or at all the issues of concern.4.2 Selection of Criteria—This guide provides information useful in selecting the appropriate criteria and measurement method to evaluate noise. In making the selection, the user should consider the following: regulatory or legal requirements for the use of a specific criterion; purpose of the evaluation (regulatory compliance, compatibility, activity interference, aesthetics, comfort, annoyance, health effects, hearing damage, etc.); types of data that are available or could be available (A-weighted, octave band, average level, maximum level, day-night level, calibrated recordings including .wav files from which various measurements could be made, etc.); and available budget for instrumentation and manpower to obtain that data. After selecting a measurement method, the user should consult appropriate references for more detailed guidance (1).74.3 Objective versus Subjective Evaluations—This guide discusses objective sound criteria based on measurements and regulations based on such. Some local noise ordinances are based solely or partially on subjective judgements of noise. Enforcement of these can be easily challenged and, in some jurisdictions, they are not permitted. These are not further considered in this guide. One way to address such situations is to evaluate the sound based on reasonable objective criteria.4.4 Soundscape Methodology—The overall sound environment as perceived outdoors is often called a soundscape. Soundscapes have both objective (quantitative) and subjective (qualitative) attributes. A soundscape evaluation methodology is evolving which includes methods and criteria that rely extensively on qualitative factors, both acoustical and non-acoustical, while including requirements for quantitative sound measurement. Two basic tenets of quantitative soundscape measurements are that the ambient sound at a location is comprised of a combination of specific acoustic events that can be measured individually and in combinations; and that the sounds should be measured using methods that represent the ways in which they are perceived by people. Development of such measurement methods specifically for soundscape studies is a part of ongoing research and is not specifically discussed in this document.1.1 This guide covers many measurement methods and criteria for evaluating environmental noise, some of which are required to be used for specific purposes by governmental regulations. It is intended to provide users who may not be familiar with them with an overview of the wide variety of available methods and criteria. It includes the following:1.1.1 The use of weightings, penalties, and adjustment or normalization factors;1.1.2 Types of noise measurements and criteria, indicating their limitations and best uses;1.1.3 Sources of criteria;1.1.4 Recommended procedures for criteria selection;1.1.5 A catalog of sources of selected available criteria; and1.1.6 Suggested applications of sound level measurements and criteria.1.2 Criteria Selection—Thorough evaluation of noise issues requires consideration of many characteristics of both the sound and the environment into which it is introduced. This guide will assist users in selecting criteria for the following:1.2.1 Evaluating the effect of existing or potential outdoor sounds on a community considering the magnitude and other characteristics of the sound and environment;1.2.2 Establishing or revising local noise ordinances, codes, or bylaws, including performance standards in zoning regulations; and1.2.3 Identifying and evaluating compliance with regulatory requirements that do not specify an acoustical measurement method or criterion or which are unclear.1.3 Reasons for Criteria—This guide discusses the many reasons for noise criteria, ways sound can be measured and specified, and advantages and disadvantages of the most widely used types of criteria. The guide refers the user to appropriate documents for more detailed information and guidance. Users needing further general background on sound and sound measurement are directed to the books listed in the References section.1.4 Criteria in Regulations—Certain criteria are specified to be used by government regulation, law, or ordinance for specific purposes. Any investigation or evaluation of a community noise issue must start with identifying applicable regulations and evaluating compliance with them. This document discusses but is not limited to regulations and ordinances. Due to the wide variation in local regulations, those are discussed more generally, and specific criteria are provided only from national government regulations. Regulations typically specify measurement methods and criteria for purposes of the regulation. Local ordinances must be written for ease of enforcement and cannot address all situations satisfactorily without becoming too complex. Such ordinances are also often prepared without competent guidance and can be too restrictive in some cases and not restrictive enough in others. Other regulations that determine government spending for noise control must balance that cost to the general public against impacts on individuals.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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