ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
คาํเตอืน
เอกสารฉบบันี ทาํขึ นเพื�อการศึกษาใหค้วามรูแ้ก ่นิสิต นักศึกษา ผูเ้ขา้ฝึกอบรม ในชั นเรียน ซึ�งผูเ้ขียนทาํขึ นชว่ยให้การเรียนการสอนง่ายขึ น ตามความเขา้ใจและประสบการณ์ของผูเ้ขียนเอง และไมม่ีส่วนรบัผิดชอบในความถูกตอ้งหรือผิดพลาดของเอกสารนี แต่อยา่งใด หากจะมีประโยชน์ต่อผูท้ี�สนใจทั �วไป ก็นับเป็นประโยชน์อีกประการของเอกสารฉบบันี ผูใ้ดจะนําไปไปใชง้าน หรือคดัลอก ทั งหมดหรือบางส่วน โปรดอา้งอิงอยา่งที�พึ�งกระทาํอยา่งเชน่เอกสารทางวชิาการทั �วไป
ISO1996-2: 2017 สรุปความโดย กฤติกา เลิศสวัสดิ์
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
� Scope and Normative references� Terms and definitions� Measurement uncertainty� Instrumentation for acoustical measurement� Principles� Operation of the source: Industrial plants� Meteorological conditions� Measurement procedures: Long-term or Short-term,
indoor/outdoor� Evaluation of the measurement results: � Extrapolation to other locations� Calculation� Information to be recorded and reported
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Annex A: (informative) Determination of radius of curvature
Annex B: (informative) Microphone locations relative to reflecting surfaces
Annex C: (informative) Selection of measurement/monitoring site
Annex D: (informative) Correction to reference condition (industrial plants)
Annex E: (informative) Elimination of unwanted sournd
Annex F: (informative) Measurement uncertainty
Annex G: (informative) Examples of uncertainty calculations
Annex H: (informative) Maximum sound pressure levels
Annex I: (informative) Measurement of residual sound
Annex J: (informative) Objective method for assessing the audibility of tones in noise—engineering method
Annex K: (informative) Objective method for assessing the audibility of tones in noise—survey method
Annex L: (informative) National and European source specific calculation models
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika LertsawatCopyright © Krittika Lertsawat
Terms and definitions
Measurement time interval
• Time interval during which measurements are conducted (time periods of integration is measurement time interval for Leq,T and LE,T
• Time interval during which measurements are conducted (time periods of integration is measurement time interval for Leq,T and LE,T
Observation time interval
• Time interval during which a series of measurements is conducted
prediction time interval
• Time interval over which levels are predicted (i.e. transportation noise source), prediction time interval corresponds to the measurement time interval except, for the former, the levels are predicted and the latter, the levels are measured.
Long-term measurement
• Measurement sufficiently long to encompass all emission situations and meteorological conditions which are needed to obtain a representative average
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika LertsawatCopyright © Krittika Lertsawat
Terms and definitions
Short-term measurement
• Measurement during measurement time intervals with well-defined emission and meteorological conditions
Receiver location
• Location at which the noise is assessed
Calculation method
• Set of algorithms to calculate the sound pressure level at a specified receiver location from measured or predicted sound power levels and sound attenuation data
Prediction method
• Subset of a calculation method, intended for the calculation of future noise levels
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika LertsawatCopyright © Krittika Lertsawat
Terms and definitions
Meteorological window
• Set of weather conditions during which measurements can be performed with limited and known variation in measurement results due to weather variationEmission window
• Set of emission condtions during which measurements can be performed with limited variation in measurement results due to variations in operating condtions
Sound path radius of curvature (Rcur)
• Radius approximating the curvature of the sound paths due to atmospheric refraction in meters
Monitor
• Instrumentation used for a single automated continuous sound monitoring terminal which monitors the LpA, their spectra and all relevant meteorological quantities (wind speed and direction, rain, humidity, atmospheric, stability, etc.
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika LertsawatCopyright © Krittika Lertsawat
Terms and definitionsAutomated sound monitoring system
• entire automated continuous sound monitoring system including all monitors, the base or central data collection position (host station) and all software and hardware involved in its operation
Reference condition
• Condition to which the measurement results are to be referred (corrected), i.e. atmospheric sound absorption at yearly average temperature and humidity and yearly average traffic flows for day, evening and night, respectively
Independent measurement
• Consecutive measurements carried out with a time space long enough to make both source operating conditions and sound propagation conditions statistically independent of the same conditions of other measurements in the series (meteorological conditions, a time space of several day)
Low-frequency sound• Sound containing frequency components of interest within the range covering the 1/3 octave
bands 16 Hz to 200 Hz
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Measurement Uncertainty
� = �� + 10�� 1 − 10��.� �� ����� �� + ���� + ���� + ����
The estimated value during the specified conditions for which a measured value is wanted In dB
The measured value including residual sound, Lres In dB
The residual sound in dB
An input quantity to allow for any uncertainty due to the selection of
receiver location in dB
An input quantity to allow for any uncertainty due to deviations
from the expected operating conditions of the source in dB
An input quantity to allow for any uncertainty due to meteorological conditions deviating from
the assumed meteorological conditions in dB
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Measurement uncertainty:
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika LertsawatCopyright © Krittika Lertsawat
Instrumentation for acoustical measurement
Valid certificate of verificationSound Level Meter• ISO/IEC 61672-1 class 1
• Temperature -10°C to +50°C Octave Band Pass Filter
• ISO/IEC 61260-1 class 1
• 1/1 octave or 1/3 octave band pass filterAcoustic Calibrator
• ISO/IEC 60942 class 1
• Twice measurement ∆L≤0.5 dBWind screen
• LpA 13mm microphone: Perpendicular -18+70 lg (v/1 m/s) dB, Horizon -32+83 lg (v/1 m/s) dB
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
• ตรวจวัดระดับเสียงของแหล่งกําเนิดเสียงที่กําลังส่งเสียงอยู่ ครั้งเดียว (Single measurement ) ภายใต้สภาวะทางอุตุนิยมวิทยาที่เหมาะสมตามเงื่อนไขที่กําหนด โดยจะต้องคํานึงถึง Lk ของเส้นทางผ่านของเสียงด้วย
Single measurement
• ตรวจวัดระดับเสียงเพื่อเก็บข้อมูลตัวอย่างหลายครั้ง (many sampled measurement ) ตลอดช่วงระยะเวลา หรือ ตรวจวัดระดับเสียงแบบระยะยาว (Long-term measurement)พร้อมกับตรวจวัดข้อมูลสภาวะทางอุตุนิยมวิทยาไว้ด้วย
Long-term measurement
Main strategies for environmental measurements:
Both types of measurements require post processing of measure data
����� = 10�� ∑ 10�.��!"#$%� dB
�$ = 10�� �"#∑ 10�.��&"#
'%� dB
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Meteorological conditions:Maximum permissible error: Long-term measurement
±0.5 K temperature of measuring device
±5 % RH of measuring device
±0.5 hPa for Barometer pressure
±0.5 m/s wind speed measuring device
±0.5 wind direction measuring device
ℎ� + ℎ)* ≥ 0.1
Transmission path condition: Hard ground + free-field conditions (long-term and short-term measurement)
ℎ� : Sound source height (m)ℎ) : Receiver height (m)* : distance between sound source and receiver
Long-term monitoring ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Wind speed and wind direction
Air temperature
Relative humidity
Occurrence of precipitation
Atmospheric stability
others
Measurement of meteorological conditions:
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika LertsawatSource: B&K Sound and Vibration Measurement Booklet, 2000
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika LertsawatSource: B&K Sound and Vibration Measurement Booklet, 2000
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
,���,./0 = 1 + 12���. dB
D≤400 m. D>400 m.
,���,./0 = 2��
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Window is a combination of emission (e.g. day, evening, night) + meteorological conditions, as shown in the table. Preferably, a window should include constant emission and propagation conditions. In many cases, the emission conditions are independent of the meteorological conditions and in other cases. (strong relationship as aircraft noise)
Meteorological window1 2 3 4
Emission window
1
2
N
Industrial sound source:
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Distance< 100 m. 100 to 300 m. > 300 m.
day night day night day night
Industry source source 48h 48h 72h 72h
Minimum time (in hours) between two measurements to be independent
Industrial sound source: ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Varia
tion
of in
depe
nden
t mea
sure
men
t: รายฤดูกาล (seasonal)
รายวัน (diurnal)
รายสัปดาห์ (weekly)
อื่นๆ (others) Depe
nden
t fac
tors:
เสียงนั้นเป็นตัวแทนของเสียงจากแหล่งกําเนิดที่ต้องการ
เลือก noise descriptor (Leq,T, Lmax)
ช่วงระยะเวลาตรวจวัดที่ครอบคลุมเหตุการณ์ของเสียงนั้น
ประเภทของเสียง (ในที่นี้มุ่งที่ Industrial source)
Industrial sound source:
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Operation of source: Source operating conditions
Leq measurement Lmax measurement
� ตรวจวัดระดับเสียงจากแหล่งกําเนิดเสียงอุตสาหกรรม เป็นแหล่งกําเนิดเสียงแบบไม่เคลื่อนที่ (stationary sound source) โดยวิธีการสุ่มเก็บตัวอย่างของระดับเสียง
� ตรวจวัดเสียง ต้องครอบคลุมการเปลี่ยนแปลงตามปัจจัยต่างๆ ของแหล่งกําเนิดเสียงในแนวทางเส้นทางผ่านของเสียง (transmission path)
� ตรวจวัดระดับเสียงสูงสุดจากแหล่งกําเนิดเสียงอุตสาหกรรม ที่เป็นตัวแทนของเสียงที่แหล่งกําเนิดนั้นทํางานตามปกติ (plant operating condition)
� ตรวจวัดระดับเสียงสูงสุดในบริเวณที่ใกล้กับสภาวะของผู้รับเสียงมากที่สุด (nearest proximity to receiver condition)
� ตรวจวัดเสียงสูงสุด ต้องครอบคลุมรอบของการทํางานของแหล่งกําเนิดเสียงและตรวจวัดจํานวนของรอบซ้ําตามหลักสถิติด้วย
Industrial sound source: ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Operation of source: Source operating conditions
Leq measurement Lmax measurement
Industrial sound source:
,��� = 5 ��' − �6� 78 − 1 ��
�
'%�
Standard uncertainty
Leq,5min or Leq,10min ที่
ระยะห่าง d เมตร
ระยะห่างนั้นครอบคลุมเสียงของแหล่งกําเนิดที่ต้องการตรวจวัดทั้งหมด
ในกรณีที่มีการเปลี่ยนแปลงสภาวะการทํางานของแหล่งกําเนิด ให้ตรวจวัด Leq,t ไปตามความถี่ และ
ช่วงระยะเวลาที่แหล่งกําเนิดเสียงทํางาน Key: X: standard deviation, s in dBY: different, in dB
��� − �6 = 0.05 ln 10 · =7 dB
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Quantities of measurement: LAeq,t or
Leq,t, LpA or Lp + time series + Time stamp
+ Met.conditions+Event detection LE,T
Attended measurement
Unattended measurement
Indoor/outdoor conditions
Long-term/Short-term measurement
Tonal noise, Impulsive noiseLow-frequency noise
Leq,T 10 minLE,T single events, -10 dB downLN,T based on Leq,1secor LAeq,T
LFMaxor LSMax
Industrial sound source:
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Industrial sound source: microphone location
Indoors:Outdoors:
Floor
Wall
ceiling
0.5 m.
0.5 m.
0.5 m.
At least 1 m. from significant sound transmission (window, door, air intakeThe distance between neighbouring microphone locations shall be at least 0.7 m.Room volume: <300 m3
at least 3 discrete locations or continuous moving microphone
National regulations can prescribe different rules to determine measurement positions.
� Selection of measurement site� Minimize the effect of residual sound
from non-relevant sound sources� Selection of microphone location
� To assess the situation at a specific location
� For other purposes o Incident sound fieldo Location with the microphone flush-
mounted on the reflecting surface o Location with the microphone 0.5 m.
to 2 m. in front of the reflecting surface
� For general mapping: a microphone height of 4.0±0.2 m. in multi-storey residential areas.
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Short-term attended measurements:Long-term unattended measurements:
Quantities to measure
Time stamp
Event detection
Leq,T (T at
least 30 min)
LE,T
LN,T Ls,max/LF,max
Tonal sound
Impulsive sound
Low-frequency sound
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Residual sound กรณี ตรวจวัดเสียง
อุตสาหกรรม
(Industrial noise)• กรณีที่มีเสียงจากการจราจร (traffic noise) จะยากในการตรวจวัดเสียงจากอุตสาหกรรม
• Octave band pass filter
• Weighting network
Outdoor conditions
• Wind induced noise
• Transmission path attenuation
uncertainty
• Measurement uncertainty
• Standard uncertainty
Residual sound measurement:
Industrial sound source:
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
To obtain accurate sound information in
specific sound-sensitive community areas
To obtain accurate sound information on the Lp
produced by different types of noise sources at the particular location
To obtain sound information to monitor
noise events
To meet monitoring system technical considerations,
particularly from more than one station under
important noise events
To monitor compliance with periodical sound
exposure level requirements
Guide of selection of measurement/monitoring site: Process of site selection
Interference from other sound sources
(i.e. traffic noise, leisure, wildlife, etc.)
Ease of access to utilities (telephone,
electric power)
Terrain and building obstruction
Ease and costs of obtaining site access and
approvals (location on private property,
costs to use the land, operation cost of access)
Monitor station security considerations (theft,
vandalism)
Likely uncertainty of the measurement
Stage 1:
Stage 2:
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Leq,T
LE,T
LN,T
LFmax, LSmax
Tonal sound
Impulsive sound
Low-frequency sound
Short-term measurement :
Long-term measurement
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Evaluation of measurement results:Assign each sample to a specific window
(meteorological/operating conditions)
Correct for residual sound
Correct each sample to reference condtions (atmospheric conditions, reference traffic conditions, time of day)
Calculate Leq,T over each window
Base on frequency of occurrence during the relevant time period
Determine the measurement uncertainty
��>,? = 10 log∑ ∆C'10�.���D,&"'
∑ ∆C''��
Duration of each measurement
� = 10 log 10�� ��⁄ − 10���� ��⁄ dB
Residual sound pressure level in dB
Measured sound pressure level in dB
Corrected sound pressure level in dB
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Standard uncertainty of measurement :�$ = 10 log
1F�510�.��&
"G
'��
H$7 = �"G��∑ 10�.��& − 10�.��!"G
' dB
Measured value representing on independent measurement in dB
Energy averaged measured sound pressure level of Nm independent measurement within meteorological and emission window k in dB
Standard uncertainty of the measurement within window k
,$ = 10 log 10�.��! + H$ dB − �$
,$ = ∑ �&��! K�!��
�!'%� dB
If the different Li is small
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Evaluation of measurement results: Determination of Lden
�L/M,$ = 10 log 5F)�.,' × 10�.��O,&,!'
�� − 10 log PL/M × 3600 ��
Statistical yearly day average of number of single events of source category i
Numerical value of the duration of the day in hours
Seconds in an hour
Average sound exposure level of each meteorological window k of each source categories i
Average sound exposure level of each meteorological window k of each source categories i
��0��'��,$��'�S�,$
P�0��'��P�'�S�
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
Measurement procedures: Industrial plants
Operation of the source
Leq
measurement
Lmax
measurement
Meteorological conditions (favorable)
Correction to reference
condition (Annex D)
Measurement procedures
Selection of time interval
Microphone location
Measurements
Evaluation of the measurement
results
Leq measurement
Lmax measurement
Level of residual
uncertainty
ISO1996-2:2017ACOUSTICS—DESCRIPTION, MEASUREMENT AND ASSESSMENT OF ENVIRONMENTAL NOISE—PART 2: DETERMINATION OF SOUND PRESSURE LEVELS
Copyright © Krittika Lertsawat
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