1、Designation: E 1014 08Standard Guide forMeasurement of Outdoor A-Weighted Sound Levels1This standard is issued under the fixed designation E 1014; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis is one of a series of standards on the measurement and evaluation of community noise. Othersin the series include Test Method E 1503 for
3、 conducting outdoor sound measurements using a digitalstatistical analysis system, Guide E 1779 which covers the preparation of a measurement plan forconducting outdoor sound measurements, and Guide E 1780 which covers measurement of soundreceived from a nearby fixed source1. Scope1.1 This guide cov
4、ers the measurement of A-weightedsound levels outdoors at specified locations or along particularsite boundaries, using a general purpose sound-level meter.1.2 Three distinct types of measurement surveys are de-scribed:1.2.1 Survey around a site boundary,1.2.2 Survey at a specified location,1.2.3 Su
5、rvey to find the maximum sound level at a specifieddistance from a source.1.3 The data obtained using this guide are presented in theform of either time-average sound levels (abbreviation TAVand symbol LAT, also known as equivalent sound level orequivalent continuous sound level abbreviated LEQ and
6、withsymbol LAeqT) or A-weighted percentile levels (symbol LX).1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is t
7、heresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 634 Terminology Relating to Building and Environmen-tal AcousticsE 1503 Test Method
8、 for Conducting Outdoor Sound Mea-surements Using a Digital Statistical Sound AnalysisSystemE 1779 Guide for Preparing a Measurement Plan for Con-ducting Outdoor Sound MeasurementsE 1780 Guide for Measuring Outdoor Sound Received froma Nearby Fixed Source2.2 ANSI Standard:3ANSI S1.4 Specification fo
9、r Sound Level MetersANSI S1.4A Specification for Sound Level MetersANSI S1.43 Specifications for Integrating-Averaging SoundLevel Meters3. Terminology3.1 DefinitionsFor definitions of acoustical barrier, impul-sive sound, measurement set and percentile levels, see Termi-nology C 6344.4. Significance
10、 and Use4.1 There are numerous situations for which outdoor soundlevel data are required. These include, but are not limited to,the following:4.1.1 Documentation of sound levels before the introductionof a new sound source (for example, assessment of the impactdue to a proposed use).4.1.2 Comparison
11、 of sound levels with and without aspecific source (for example, assessment of the impact of anexisting source).1This guide is under the jurisdiction of ASTM Committee E33 on Building andEnvironmentalAcoustics and is the direct responsibility of Subcommittee E33.09 onCommunity Noise.Current edition
12、approved March 1, 2008. Published May 2008. Originallyapproved in 1984. Last previous edition approved in 2000 as E 101484(2000).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informati
13、on, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Terminology C 63481a was used in the development of this guide.1Copyright ASTM International, 100 Barr H
14、arbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.3 Comparison of sound levels with criteria or regulatorylimits (for example, indication of exceedence of criteria ornon-compliance with laws).4.2 This guide provides a means for selecting measurementlocations, operating a
15、sound level meter, documenting theconditions under which the measurements were performed, andrecording the results.4.3 This guide provides the user with information to (1)make and document the sound level measurements necessaryto quantify relatively steady or slowly varying outdoor soundlevels over
16、a specific time period and at specific places and (2)make and document the physical observations necessary toqualify the measurements.4.4 The user is cautioned that there are many nonacousticalfactors that can strongly influence the measurement of outdoorsound levels and that this guide is not inten
17、ded to supplant theexperience and judgment of experts in the field of acoustics.The guide is not applicable when more sophisticated measure-ment methods or equipment are specified. This guide, depend-ing as it does on simplified manual data acquisition, isnecessarily more appropriate for the simpler
18、 types of environ-mental noise situations.As the number of sources and the rangeof sound levels increase, the more likely experienced special-ists with sophisticated instruments are needed.4.5 This guide can be used by individuals, regulatoryagencies, or others as a measurement method to collectacou
19、stical data for many common situations. Criteria forevaluating or analyzing the data obtained are beyond the scopeof this guide.4.6 Note that this guide is only a measurement procedureand, as such, does not address the methods of comparison ofthe acquired data with the specific criteria. No procedur
20、es areprovided for estimating or separating the influences of two ormore simultaneously measured sounds. This guide can beuseful in establishing compliance when the measured data arebelow a specified limit.4.7 Paragraph 8.2.1 outlines a procedure that can be used fora survey of the site boundary; pa
21、ragraph 8.2.2 for a survey ofspecified monitoring points; and paragraph 8.2.3 for determin-ing the location and magnitude of maximum sound level.5. Apparatus5.1 Acoustical Measurements:5.1.1 Sound Level Meter (required) Type 2, or better, inte-grating averaging, as defined by ANSI S1.43, and ANSI S1
22、.4,ANSI S1.4A with statistical analysis capability, and, with atleast a 60-dB dynamic range.5.1.1.1 The instrument should have an a-c output port topermit use of headphones.5.1.1.2 The instrument shall be equipped with anA-Weighting network. It is recommended that the instrumentalso be equipped with
23、 a C-weighting or a Z-weighting, or both.NOTE 1Z-weighing is an unweighted (flat) network, that is sometimescalled “Linear” by manufacturers.5.1.2 Microphone Windscreen (required), recommended bythe sound level meter manufacturer.5.1.3 Acoustical Calibrator (required), with adaptors nec-essary to fi
24、t the microphone.5.1.4 Set of Headphones (desirable), compatible with andelectrically connected to the a-c output of the sound levelmeter. Monitoring the output of the sound level meter withheadphones may enable the operator to detect equipmentmalfunctions or anomalies in the data caused by wind, hu
25、mid-ity, and electrical interference.5.1.5 Tripod (desirable), to ensure a steady and repeatablemicrophone position.5.2 Physical Measurements:5.2.1 To ensure the precision of values derived from thesemeasurements, the accuracy of distance measurements shall bewithin 5 %. Any instrument that provides
26、 this degree ofaccuracy is satisfactory.5.2.2 Pocket Compass (desirable), used for site layout workand for determination of wind direction.5.2.3 Site Map (optional).5.3 Meteorological MeasurementsAny of the many avail-able general-accuracy meteorological instruments may be usedin order to enable the
27、 measurement of:5.3.1 Wind speed (5-km/h or 2.5-mph increments),5.3.2 Wind direction (in octants),5.3.3 Relative humidity (in 10 % increments),5.3.4 Dry bulb temperature (in 2C or 5F increments).6. Calibration6.1 The calibration of the sound level meter shall bechecked using an acoustical calibrator
28、 immediately before andafter each measurement set, in a manner prescribed by themanufacturer. Adjustments, if required, shall be made at thistime. If the change in the calibration reading, as shown on thesound level meter, is 1 dB or greater, the data gathered sincethe preceding calibration are cons
29、idered invalid and should bediscarded. It is strongly recommended that an instrument thatshows an unexplained calibration drift greater than 1.5 dB overa 24 h or less be taken out of service until the cause of the driftcan be identified and remedied.6.2 The sound level meter and the acoustical calib
30、rator shallhave been thoroughly calibrated with equipment traceable to arecognized standards organization, and following recommen-dations of the instrument manufacturer with 1 year, or a periodspecified the measurement plan, prior to starting the measure-ments. Included in this calibration shall be
31、checks of frequencyresponse, amplifier sensitivity, internal noise, and verificationof correct operation of meter circuits and microphone.7. Interference7.1 Interfering noise must be identified and accounted for.Asound can be interference if it is concentrated in a small areaand not representative o
32、f the sound that is to be documented.Ameasurement plan should address how such sounds are to betreated. It may be advisable for many types of sound sources toavoid interferences by testing at night. If it is determined thata given sound is an interference, the measurement locationmight be moved to a
33、 position where the contribution of theinterfering sound is acceptably minimized or, if possible, theconduct of the survey may be modified so as to avoid theinfluence of the interference. Some of the more commonsources of interference are discussed in the following:E10140827.1.1 WindWind may influen
34、ce sound level measure-ments, even with a windscreen in place, particularly at windspeeds above 20 km/h (12 mph). Manufacturers instructionsshall be followed with respect to meter limitations under windyconditions. When wind speeds approach or exceed 20 km/h,headphones shall be used to monitor the s
35、ound level meteroutput or the sound level meter indicator shall be carefullyobserved to determine if fluctuations correspond to wind speedor actual sound sources. Data obtained during intervals whenwind is influencing the measurements shall not be used. Nomeasurements shall be made when steady wind
36、speeds exceed20 km/h. Propagation of sound from a source will be influ-enced by the direction of wind relative to the source andmeasurement positions. Measurements should be taken atdifferent times of the year in different wind conditions to fullyidentify the acoustical character of the environment.
37、7.1.2 Rain and SnowMeasurable precipitation almost al-ways influences outdoor sound levels. For example, tiresrolling on a paved surface result in higher sound levels whenthe pavement is wet. Also, fallen snow may affect the propa-gation of sound so that sound levels may be different with andwithout
38、 fallen snow. For these reasons, making measurementsduring precipitation or when pavement is wet or snow coveredis discouraged. If it is necessary to obtain data when groundsurfaces are wet or snow covered, the conditions shall becarefully described in the report. High humidity can influencecertain
39、microphones; manufacturers instructions should beclosely followed under these conditions.7.1.3 Impulsive SoundThis guide is not intended to evalu-ate impulsive sound because Type 2 sound level metersoperating in “fast” or “slow” modes do not accurately orprecisely measure impulse sound. If occasiona
40、l impulses occurduring the survey, estimation of their magnitude may beattempted using the fastest available meter response, either“fast,” “peak,” or “impulse.” The maximum meter reading, themeter response setting, and the repetition rate within themeasurement set shall be reported. Whenever most of
41、 thesound level meter readings in any measurement set areinfluenced by impulsive sound, this guide shall not be used.7.1.4 Tonal SoundOccasionally it is necessary to measuresources of pure tonal sound perceived as a “buzz,” “hum,” or“whistle.” Since both the operators body and reflections cansignifi
42、cantly influence the sound level meter indication whentones are present, the report must include observations of tonalsound when present.7.1.5 Power LinesElectromagnetic radiation from highvoltage transmission lines, or strong television or radio signalsmay affect the sound level meter indication. T
43、he operatorshould use caution when these are nearby. Such electricalinterference problems, when they occur, might result in wildand unexpected swings of the sound level meter indicator orupward indications even when the instrument is turned off.These effects may be audible through monitoring headpho
44、nes.This is the most effective way to detect these conditions andother anomalies.7.1.5.1 A nonelectrical problem related to power lines is thegeneration of sound by aeolian strumming, or buzzing orrattling by wires which are not tightly secured to insulatorsnear a power line. Noise from power lines
45、can increasedramatically with high humidity, especially during light rain. Ina quiet rural environment such sounds can easily exceed theambient level.7.1.6 Meteorological EffectsTemperature inversions andother meteorological conditions may strongly influence thepropagation of sound over long distanc
46、es. Therefore, whensound from sources at horizontal distances of about 300500 m(10001600 ft) or more need to be quanitified, measurementsshould taken at different times of the year in different weatherconditions to fully identify the acoustical character of theenvironment.7.1.7 Nature SoundsDuring c
47、ertain times of the year,naturally occurring sounds such as from birds or insects(crickets, locusts) may interfere or dominateA-weighted soundlevels particularly during evening and nighttime periods. Suchnoises should be noted in the report. Where possible, an effortmay be made to quantify or accoun
48、t for such influence bymaking measurements at different times or different locationsto document conditions with and without such naturallyoccurring interfering sounds.8. Procedure8.1 Preparation of EquipmentPrepare the sound levelmeter for use as follows:8.1.1 Check the battery condition indicator (
49、recheck every15 to 30 min during the measurement set).8.1.2 Verify calibration of the sound level meter in accor-dance with the manufacturers instructions.8.1.3 Place the windscreen over the microphone.8.1.4 Set the weighting to “A.”8.1.5 Set the response to “slow” or “fast” as required in7.1.3 (unless otherwise specified).8.1.6 Select a range so that the sound level meter reading ison scale.8.1.7 Support the instrument and orient the microphone inaccordance with the manufacturers instructions. In the ab-sence of a specified height, position the microphone between
