1、Designation: E 1014 84 (Reapproved 2000)Standard 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 r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the measurement of A-weightedsound levels outdoors at specified locations or along particularsite boundar
3、ies, 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 Survey to find the maximum sound level at a specifieddistance from a source.1.3 Since outdoor sound levels almo
4、st always vary withtime over a wide range, the data obtained using this guide maybe presented in the form of a histogram of sound levels. Thedata obtained using this guide enables calculations of averageor statistical sound levels for comparison with appropriatecriteria.1.4 This standard does not pu
5、rport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility 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:C
6、634 Terminology Relating to Environmental Acoustics22.2 ANSI Standard:S1.4 Specification for Sound Level Meters33. Terminology3.1 DefinitionsFor definitions of terms used in this guide,see Terminology C 634.43.2 Definitions of Terms Specific to This Standard:3.2.1 barrierany obstacle that blocks the
7、 line-of-sightbetween a source and a receiver or a measurement location.3.2.2 impulse noisea brief, intrusive sound, such as thatassociated with a tire blowout, operation of a power press, thedischarge of a firearm, or a shout.3.2.3 measurement setthe set of data obtained at a mea-surement location
8、during a specific time period. For the typesof measurements covered by this guide, evaluation of a sitemay require several measurement sets. The time period isflexible but should not extend beyond the time when theconditions influencing noise, or atmospheric conditions affect-ing noise propagation,
9、are reasonably uniform. As an example,a significant change in traffic density or start-up of a machineindicate the beginning or end of a measurement set.4. Significance and Use4.1 There are numerous situations for which outdoor soundlevel data are required. These include, but are not limited to,the
10、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 of sound levels with and without aspecific source (for example, assessment of the impact of anexisting source).4.1.3 Comparison of
11、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 sound level meter, documenting theconditions under which the measurements were performed, andr
12、ecording 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 a specific time period and at specific places and (2)make and document the physical observatio
13、ns 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 intended to supplant theexperience and judgment of experts in the field of acoustics.1This guide is
14、 under the jurisdiction of ASTM Committee E33 on EnvironmentalAcoustics and is the direct responsibility of Subcommittee E33.09 on CommunityNoise.Current edition approved July 27, 1984. Published September 1984.2Annual Book of ASTM Standards, Vol. 04.06.3Available from American National Standards In
15、stitute, 11 W. 42nd St., 13thFloor, New York, NY 10036.4Terminology C 634 81a was used in the development of this guide.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.The guide is not applicable when more sophisticated measure-ment
16、methods or equipment are specified. This guide, depend-ing as it does on simplified manual data acquisition, isnecessarily more appropriate for the simpler types of environ-mental noise situations. As the number of sources and the rangeof sound levels increase, the more likely experienced special-is
17、ts with sophisticated instruments are needed.4.5 This guide can be used by individuals, regulatoryagencies, or others as a measurement method to collectacoustical data for many common situations. The data areobtained in the form of a histogram, a graph, or a tableindicating the number of occurrences
18、 of each sound levelobserved during the measurement. Criteria for evaluating oranalyzing the data obtained are beyond the scope of 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 criteri
19、a. No procedures 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 sit
20、e boundary; paragraph 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, as defined byANSI S1.41971 preferably with an a-c output
21、port to permitthe use of headphones.5.1.2 Microphone Windscreen (required), recommended bythe sound level meter manufacturer.5.1.3 Acoustical Calibrator (required), with adaptors nec-essary to fit the microphone.5.1.4 Set of Headphones (desirable), compatible with andelectrically connected to the a-
22、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, humid-ity, and electrical interference.5.1.5 Tripod (desirable), to ensure a steady and repeatablemicrophon
23、e position.5.2 Physical Measurements:5.2.1 To assure an accuracy of 1 dB in values derived fromthese measurements, the accuracy of distance measurementsmust be within 5 %. Any instrument that provides this degreeof accuracy is satisfactory.5.2.2 Pocket Compass (desirable), used for site layout worka
24、nd 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 measurement of:5.3.1 Wind speed (5-km/h or 2.5-mph increments),5.3.2 Wind direction (in octants),5.
25、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 immediately before andafter each measurement set, in a manner prescribed by themanufacturer. Adjust
26、ments, if required, shall be made at thistime. Calibration shall also be verified if the sound level meteris abused (dropped, etc.). If the change in the calibrationreading, as shown on the sound level meter, is 1 dB or greater,the data gathered since the preceding calibration are consideredinvalid
27、and should be discarded.6.2 The sound level meter and the acoustical calibrator shallhave been thoroughly calibrated with equipment traceable tothe National Institute of Standards and Technology within 1year before the survey. Included in this calibration shall bechecks of frequency response, amplif
28、ier sensitivity, internalnoise, and verification of correct operation of meter circuitsand microphone.7. Interference7.1 Wind may influence sound level measurements, evenwith a windscreen in place, particularly at wind speeds above20 km/h (12 mph). Manufacturers instructions shall be fol-lowed with
29、respect to meter limitations under windy condi-tions. When wind speeds approach or exceed 20 km/h, head-phones shall be used to monitor the sound level meter output orthe sound level meter indicator shall be carefully observed todetermine if fluctuations correspond to wind speed or actualsound sourc
30、es. Data obtained during intervals when wind isinfluencing the measurements shall not be used. No measure-ments shall be made when steady wind speeds exceed 20 km/h.7.2 Measurable precipitation almost always influences out-door sound levels. For example, tires rolling on a paved surfaceresult in hig
31、her sound levels when the pavement is wet. Also,fallen snow may affect the propagation of sound so that soundlevels may be different with and without fallen snow. For thesereasons, making measurements during precipitation or whenpavement is wet or snow covered is discouraged. If it isnecessary to ob
32、tain data when ground surfaces are wet or snowcovered, the conditions shall be carefully described in thereport. High humidity can influence certain microphones;manufacturers instructions should be closely followed underthese conditions.7.3 This guide is not intended to evaluate impulse noisebecause
33、 Type 2 sound level meters operating in “fast” or“slow” modes do not accurately or precisely measure impulsenoise. If occasional impulses occur during the survey, estima-tion of their magnitude may be attempted using the fastestavailable meter response, either “fast,” “peak,” or “impulse.”The maximu
34、m meter reading, the meter response setting, andthe repetition rate within the measurement set shall be reported.Whenever most of the sound level meter readings in anymeasurement set are influenced by impulse noise, this guideshall not be used.7.4 Occasionally it is necessary to measure sources of p
35、uretone noise perceived as a “buzz,” “hum,” or “whistle.” Sinceboth the operators body and reflections can significantlyE 10142influence the sound level meter indication when tones arepresent, the report must include observations of tonal noisewhen present.7.5 Electromagnetic radiation from high vol
36、tage transmis-sion lines, or strong television or radio signals may affect thesound level meter indication. The operator should use cautionwhen these are nearby. Such electrical interference problems,when they occur, might result in wild and unexpected swingsof the sound level meter indicator or upw
37、ard indications evenwhen the instrument is turned off. These effects may be audiblethrough monitoring headphones. This is the most effective wayto detect these conditions and other anomalies.7.6 Temperature inversions and other meteorological condi-tions may strongly influence the propagation of sou
38、nd overlong distances. Therefore, when sound from sources at hori-zontal distances of about 500 m (1600 ft) or more need to bemeasured, an acoustical specialist should be consulted.7.7 During certain times of the year, naturally occurringsounds such as from birds or insects (crickets, locusts) maydo
39、minate A-weighted sound levels particularly during eveningand nighttime periods. Such noises should be noted in thereport. Where possible, an effort may be made to documenttheir influence by making measurements at different times ordifferent locations to document conditions with and withoutsuch natu
40、rally occurring sounds.8. Procedure8.1 Preparation of EquipmentPrepare the sound levelmeter for use as follows:8.1.1 Check the battery condition indicator (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 in
41、structions.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 as required in 7.3 (unlessotherwise 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 ina
42、ccordance with the manufacturers instructions. In the ab-sence of a specified height, position the microphone between1.2 m (4 ft) and 1.5 m (5 ft) above the ground.8.2 Selecting Measurement Locations and Times:8.2.1 Survey Around a Site BoundaryFollow proceduresin 8.2.1.1-8.2.1.5 when it is necessar
43、y to measure A-weightedsound levels at the boundary of a site.8.2.1.1 Select the time periods of the survey. In general, thetime of day that each measurement set is obtained should besuch that the sound levels are representative of a specificcondition. The period of operation of a time-varying ortim
44、e-restricted source may also dictate the time to measure. Inthe absence of specified time periods the following shall apply:(1) day (7 am through 7 pm), (2) evening (7 pm through 10pm), and (3) night (10 pm through 7 am).(1) Unless otherwise specified, at least one measurementset within each time pe
45、riod should be taken. For example, if thesource is predominantly traffic noise, it may be useful tosubdivide the daytime period into “rush” hours (that is, from 7to 9 am and from 4 to 6 pm) and “non-rush” hours for purposesof comparing noise levels with and without peak traffic flow.(2) Both a weekd
46、ay (Monday to Friday) and a weekend day(Saturday or Sunday) should be monitored if a difference insound levels is expected unless otherwise specified. Whenevera particular noise source tends to dominate the measured soundlevel only intermittently, the survey shall include periods withand without the
47、 source present, as two different measurementsets.8.2.1.2 The sound level meter may be used in selecting thelocations on the basis of sound level. For each time period,walk the site boundary, measure and note the trend of soundlevels. Select a minimum of two locations to meet one or moreof the follo
48、wing:(1) Local maximum, the location where the highestA-weighted sound level is observed.(2) Local minimum, the location where the lowestA-weighted sound level is observed.8.2.1.3 Alternatively, locations may be selected for otherreasons:(1) Sensitive Locations, considering sound sources andreceiver
49、s either inside or outside the site, including upper floorsof nearby structures.(2) Locations Nearest to a Community, considering soundsources within the site.(3) Intermediate Locations, locations selected so that theindicated sound level at adjacent locations might not differ bymore than 5 dB.(4) Other Locations: (1) so that locations are separated byno more than one-half the site perimeter; (2) so that suchconditions as variable terrain, acoustical barriers adjacent tosite activities, and presence of adjoining structures are consid-ered.NOTE 1The location of the microph
