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Krittika Lertsawat@copyright2009

ISO 1996/1-2003: AcousticsDescription,

measurement and assessment of

environmental noise--Part 1: Basic quantities,

assessment proceduresKrittika Lertsawat@copyright2009

Scope of ISO 1996/1-2003General

+ 2+


Sound designations Total sound Specific sound Residual sound

Residual sound

Sp.A

Sp.B

Sp.C

Total sound


Sound designations Total sound Specific sound Residual sound

Residual sound

Sp.A

Sp.B

Sp.C=

Residual sound

Total sound


ISO 1996/1-2003

Fluctuating sound 222 impulse 2

Intermittent sound 2


Symbols for Sound Pressure and Sound Exposure Levels

Time-averaged and frequency-weighted sound pressure level LpAFMaximum time-averaged and frequency-weighted sound pressure level LAFmaxPercent exceedance level LAFNTPeak sound pressure level LCpeakSound exposure level LAEEquivalent-continuous sound pressure level LAeqTRating sound exposure level LRERating equivalent continuous level LReqT


Noise Annoyance in ISO 1996/1-2003

Krittika Lertsawat@copyright2009Adjusted Levels

Rating Levels

Adjusted Sound Exposure Levels

Adjusted Equivalent Sound Pressure Levels

One sound source

Combined sources


Typical level adjustments

Source of sound

Road trafficAircraftRailwayIndustry

03 to 6

-3 to -60

Source character

Regular impulsiveHighly impulsive

High-energy impulsiveProminent tones

512

Annex B3 to 6

Time periodEveningNight

Weekend daytime

5105

Specification Level adjustment (dB)


Composite whole-day rating levels

Day-night sound pressure level

Day-Envening-Night SPL


How to write the assessment reports?How to write the assessment reports?How to write the assessment reports?How to write the assessment reports?

The reference time interval

The long-term time interval

For measurement: instrumentation, its calibration, layout, measurement time intervals

The rating level and components (acoustic levels)

A description of sound source (reference time intervals)

A description of operating conditions of sound sources

A description of the assessment site: topography, building geometry, ground cover and conditions


How to write the assessment reports?How to write the assessment reports?How to write the assessment reports?How to write the assessment reports?

A description of any procedures used to correct for contamination by residual sound and description of the residual sound

The results of estimation of long-term annoyance response of community

A description of the weather conditions during measurement: wind direction and speed, cloud cover, precipitation

Uncertainties of the results and method used to take these uncertainties into account

For calculation: original input data and activities performed to verify the reliability of the input data


Recommended Estimation:Recommended Estimation:Recommended Estimation:Recommended Estimation:

Long-term intervals for estimating the annoyance

response of communities: typically a year typically a year typically a year typically a year (Appendix D: Estimated percentage of a population highly annoyed as a function of adjusted day/night sound levels [Schultz, T.J., 1978, 1994, 1998]Appendix E: Annoyance caused by exposure to sound in multi-source environments)

Additional requirements for reporting compliance with limits: the relevant section of the noise limit regulation, a description of prediction model with its assumption, uncertainties to the predicted value of the sound descriptor.


ISO 1996/2-2007:AcousticsDescription,

measurement and assessment of environmental noise--Part 2: Determination of environmental noise levels


Scope of ISO 1996/2-2007Description

By direct measurement By extrapolation of measurement results by means of calculation Excessively by calculation (mathematical model)

Recommendations

Given regarding preferable conditions for measurement or calculation to be applied in cases where other regulations do not apply Applied to measure with any frequency weighting or any frequency band Provided guidance to evaluate the uncertainty of the result of a noise measurement

Remarks

Note 1: as this part of ISO1996 deals with measurements under actual operating conditions, there is no relationship between this part of ISO1996 and other ISO standards specifying emission measurements under specified operating conditons

Note 2: subscript frequency and time weighting


Standard Uncertainty

Combined standard

uncertainty

Expanded measure-

ment uncertainty

Due to instrumentation a

1.0 dB

Due to operating

conditions b

X dB

Due to weather and

ground conditions c

Y dB

Due to residual sound d

Z dB

a For IEC 61672-1:2002 class 1 instrumentation. If other instrumentation (IEC 61672-1:2002 class 2 or IEC 60651-1:2001/ IEC 60804:2000 type 1 sound level meter) or directional microphones are used, the value will be larger.b To be determined from at least three, and perferably five, measurement under repeatability conditions (the same measurement procedure, the same instruments, the same operator, the same place) and at a position where variations in meteorological conditions have little influence on the results. For long-term measurements, more measurements are required to determine the repeatability standard deviation. For road-traffic noise, some guidance on the value of X is given in 6.2. c The value varies depending upon the measurement distance and the prevailing meteorological conditions. A method using a simplified meteorological window is provided in Annex A (in this case . For long-term measurements, it is necessary to deal with different weather categories separately and then combined together. For short-term measurement, variations in ground conditions are small. However, for long-term measurements, these variations can add considerably to the measurement uncertainty.d The value varies depending on the difference between measured total values and the residual sound. Krittika Lertsawat@copyright2009

Sound Level Meter (SLM)

Meteorological conditions:-Temperature (-10oC to +50oC: class 1)-Temperature (-10oC to +40oC: class 2)

Calibrations:-Applied microphone to the calibration of the entire measuring system at one or more frequencies-long periods of measurement times, calibration can be checked acoustically or electrically at regular intervals: once or twice a day

IEC 61672-1:2002-Class 1-Class 2IEC 60651 or 60804

-Wind shield-Cable-Recorders-Heaters

CalibratorIEC 60942:2003

IEC 61260:19951/1 or 1/3 octave

band analysis

Instrumentations


Operation of the Source


Leq,t Measurement Lmax Measurement

Road Traffic

During measurement:

- Number of vehicles pass-bys

- Vehicles categories (heavy/light) by

vehicle weight

- Average traffic speed

- Traffic conditions (if any)

- Average the variation in individual

vehicle noise emissio

-Differ among vehicle

categories

- Certain speed due to

individual differences among

vehicles and variation in

speed or driving patterns

- Determined based-on

measured Lp during at least

30 pass-bys of vehicles of

the category considered

Recommended conditions:

- Standard uncertainty of X :

n is total number of vehicle pass-bys

- LE from individual vehicle pass-bys and

traffic statistics to calculate Leq,t

- Minimum number of vehicles per

categories shall be 30



Rail Traffic

Conditions:

- Pass-by noise from

at least 20 trains

- Each category of train

potentially contributing

significantly to the overall Leq,tshall be represented by at least

five pass-bys

- measurement shall be

continued on a subsequent day

(if necessary)

- Recorded Lmax at least

20 pass-bys trains

- if it is not possible to obtain this many recordings, it shall

be stated in the report how

many train pass-bys

- it is will influenced the

uncertainties of measurement



Air Traffic

Conditions:

- Pass-by noise from

5 fly-over aircrafts or

more of each types of

aircrafts

- Traffic pattern (runway

use, take-off and landing

procedures, airfleet mix,

time-of-day distribution of

the traffic)

- If the recorded Lmax at specific

residential area, the aircraft types with

the highest noise emission will be

recorded using flight-tracks of nearest

proximity.

- at least 5 and preferably 20 or more of

each of most noisy relevant types of fly-

over aircrafts occurrences

- if it is not possible to obtain the 20 occurrences, it shall be stated in the

report how many of them recorded and

analyzed, influenced to the uncertainties

of measurement.



Industrial Plants

-Source operating shall be divided into classes

-Time variation of each classes shall be

reasonably considered the variations of

stationary emission, weather condition in

transmission-path attenuation

-Time variation shall be determined from

5 10 minutes of measured Leq,t at a distance long enough to

include all major sources, and

short enough to minimize

meteorological effects

-Time variation in cyclic sources shall be

included a whole number of cyclic

-Frequency and duration of each classes of operating condition shall be

recorded

-Ensure that measurement

period contains the plant

operating condition with

the highest noise

emission occurring at the nearest proximity to the

receiver location

-At least five events of the most noisy relevant

operation condition.


Conditions favourable to sound propagation

Average Sound Pressure Levels under a Range of

Weather Conditions

Weath

er Co

nd

ition

sDownward sound-ray (ISO 1996-2:2007 Annex A)i.e. if R < 10 kilometers

(1) Wind blow from dominant source to receiver

(2) Wind speed (at 3-11 m. above the ground) is between 2-5 m/s during daytime or >0.5 m/s at night-time

(3) No strong, negative temperature gradient occurs near the ground

-All different weather conditions can be combined with calculations taking weather statistics into account to determine long-term averages

-The combination of source operating conditions and weather-dependent sound propagation shall be taken into account, so that every important component of sound exposure is represented in the measurement results

-To determine a long-term average noise level as it can occur during a year, it is necessary to take into account the variations in source emission and sound propagation during a whole year

General-No precipitation-Road/track surface shall be dry-Ground surface shall not be covered with snow or ice, frozen or soaked by waters-Soft ground need correction


Low Frequency Sound Sources

Examples of sources: bridge vibrations, subway trains, stamping plants, pneumatic construction equipment, etc.

Procedures and discussion:- 3 measurement positions (indoor with room volumes < 300 m3 and additional microphones in large room)- at least a position should be at corner position and other in free field conditions- 1/3 octave band analysis should be corner positions

Annex B of ISO 1996-1:2003 for more discussionKrittika Lertsawat@copyright2009

How to select measurement time interval?Microphone Location:

Outdoor Measurem

ent P

roced

ure

- Select an appropriate observation and measurement time intervals (free field pos.)- Select measurement time interval to cover all significant variations in noise emission and propagation (1) Continuous: at least three periods (2) Cyclic: complete cycle(3) Single events: LE

a) Reference condition is free field position. (-6dB/DD)b) Microphone flush-mounted on the reflecting surface.c) Microphone 0.5 to 2.0. meters in front of the reflecting surface. (-3dB/DD)

Microphone Height:

Density of grid: not more than 5dB

Microphone Location: IndoorAt least 3 discrete meas.pos. (1)Receiver position with spending time(2)Continuous noise position(3)Use a rotating microphone (at least 15s moving

between two microphone for escaping the reverberant effects)

Others microphone pos. are (1)At least 0.5 m. from walls, ceiling, or floor(2)At least 1 m. from significant sound transmission

elementsi.e. doors, windows, openings(3)At least 0.7 m. from neighboring microphone

General mapping

Multi-storey residential areas

One-storey residential areas and recreational areas

or

Permanent monitoring position

other


Information to be recorded and reported?Information to be recorded and reported?Information to be recorded and reported?Information to be recorded and reported?

Time, day and place for measurements Instrumentation and its calibration Measured and, if relevant, corrected sound pressure levels (Leq,t, LE, Lmax),

A or C weighted, and optionally, in frequency bands Measured N percent exceedance level including the base on which it is

calculated Estimate of measurement uncertainty together with the coverage probability Information on residual sound pressure levels during the measurements Time intervals for the measurements Through description of the measurement site, including ground cover and

condition, and locations, including height above ground, of microphone and sources

Description of the operating conditions, including number of vehicle/train/aircraft pass-bys specified for each suitable category

Description of the meteorological conditions, including wind speed, wind direction, cloud cover, temperature, barometric pressure, humidity and presence of precipitation and location of wind and temperature sensors

Method (s) used to extrapolate the measured values to other conditionsKrittika Lertsawat@copyright2009

ISO 1996-1: 2003AcousticsDescription, measurement and assessment of environmental noisePart 1: Basic quantities and assessment procedures

ISO 1996-2: 2007AcousticsDescription, measurement and assessment of environmental noisePart 2: Determination of environmental noise levels


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