Periodic Test for Environmental Noise Test

7/23/2019 Periodic Test for Environmental Noise Test

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METRO ROLLING STOCK (TRAIN)

NOISE PERIODIC TEST PROCEDURE


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Mumbai Metro One Pvt LtdDivision Rolling Stock

System/Equipment Train

Document No RS-MN-Document Type Routine/Periodic Test Procedure

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Name of Document: Periodic Test Procedure of Noise Test

Amendment Record

RevNo

AmendedDate

AmendedBy

Section/pageAmended

Amended details


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1. Title

Routine/Periodic test procure of Noise Test.

2. Purpose of Test Procedure

The Test procedure for measurement of exterior noise of Rolling Stock, when in standstill and during

motion of vehicle, Noise monitoring test shall be conducted after an interval of time or after modification

of Rolling stock.

The objective of the test is to check and confirm acoustic comfort level as per ISO 3095 and as per The

Noise Pollution Rules, 2000.

3. Reference Documents

ISO 3095: Railway ApplicationsAcousticsMeasurement of Noise emitted by Rail bound vehicles.

The Noise Pollution (Regulation and Control) Rules, 2000. Ministry of Environment & Forests.

IEC 61672-1: ElectroacousticsSound level meters

FTANoise and Vibration Manual

4. Definitions & Abbreviations


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4.1.6. A-weighted equivalent continuous sound pressure level:Equivalent (average) sound pressure level in dB for a period of time.

LpAeq.T : A-weighted equivalent continuous sound pressure level in dBpA(t) : RMS A-weighted sound pressure in Pa

po : Reference sound pressure; po= 20 PaT : Time interval in sec.

4.1.7. A-weighted equivalent continuous sound pressure level:Equivalent (average) sound pressure level in dB for a period of time.


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8.Procedure: Measurement of Exterior Noise

Vehicle (Train) noise is measured in following types to check and confirm the acoustic noise level

limit, when the Train is at stationary and running.

1. Noise level measurement of Stationary Train

2. Noise level measurement of Running Train at constant speed.

3. Environmental Noise measurement and Noise impact analysis.

8.1 Noise level measurement of stationary Train.

8.1.1 Measurement position:

For stationary Train, the measurement points as shown below. Each car Noise ismeasured from center of the car, 7.5 meter from tract center line and 1.2 meter above

the track.


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8.1.4 Back ground sound pressure level

For monitoring test Difference ofA-Weighted sound pressure levelshall be at least

5dB above.

If the difference in sound level is less than 10dB the reading obtained shall becorrected as per below table.

Difference of A-Weighted sound pressurelevel dB

Correction to be added to A-Weighted sound

pressure level obtained from the vehicle inpresence of back ground noise dB.

> 10 0

6 to 9 -1

5 -2

8.1.5 Test Procedure Microphone should be placed in exterior at the center of the car, 7.5m from track

center and 1.2m above the rail top. Measurement period shall be T=20sec as per ISO

3095 Th i ti i t l b d d t 5 b t it h ld b j tifi d i

Difference of A-Weighted

sound pressure level

Noise measured from the vehicle

in presence of back ground noiseA-weighted back ground sound

pressure alone= -


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Measuring point DT-1 M-1 M-2 DT-2

1st

2 nd

3rd

Average

8.2 Noise level measurement of Running Train at constant speed

8.2.1 Measurement position: Microphone should be placed 7.5 meter from tract center line and 1.2 meter above

the track.


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8.2.4 Back ground sound pressure level

For monitoring test Difference of A-Weighted sound pressure level shall be at least

5dB above.

If the difference in sound level is less than 10dB the reading obtained shall becorrected as per below table.

Difference of A-Weighted sound pressure

level dB

Correction to be added to A-Weighted sound

pressure level obtained from the vehicle in

presence of back ground noise dB.> 10 0

6 to 9 -1

5 -2

8.2.5 Test Procedure Over the measurement section of the track, the train should run at the chosen constant

speed or at maximum speed 80kmph, the speed should be stabilized within 5%.

The measurement time interval T will begin, when the front of the train is passing the

i h d ill d h f th hi l i l i ( i ) th

Difference of A-Weighted

sound pressure level

Noise measured from the vehicle

in presence of back ground noiseA-weighted back ground sound

pressure alone= -


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Record sheet:

Measuring

point

Train Speed Measured value in

dB

Ambient/

Acoustic noise

Remarks

1st

2 nd

3rd

4th

5th

6th

Average


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8.3 Assessment of Transit Noise Impact on Environmental Noise Level:

Assessment of Metro Trains Noise impact on Noise sensitive location such as Residential

Building, Schools and Hospitals, around Metro viaduct shall be measured and analyzed.

Detail Noise Assessment Test:

1. Screening Procedure.2. General Noise Assessment.3. Detail Noise Analysis.

3.1. Measurement of Noise Exposure level of Metro Trains3.2. Measurement of Existing Noise Exposure level.3.3. Analysis of Measurements and Noise Impact Criteria.

3.3.1. Ldn Calculation of Metro Trains.3.3.2. Project Noise vs. Distance exposure curve.

3.4. Analysis of Noise impact on nearby location and for Mitigation.3.5. Procedure to measure Project Noise and Environmental using NTi

Audio meter3.6. Project Noise and Environmental Noise Record Sheet.

1. Screening Procedure:

The noise screening procedure is to identify location, where a project may cause noise impact. For

i ll i i i l d id d b i i l


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3.2. Measurement of Existing Noise Exposure level.

Measurement of existing noise on nearby location, where the project noise has been measured.

Existing noise shall me measured for a whole day or an hour measurement, depends on the locationand environment.

Recommended Microphone position to Measure Existing Noise:


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Option -1:

Measure full day noise exposure level Ldn. If the location is exposed with high external noise

sources and accurate/actual Existing noise.Measurement shall be taken generally between Noon Monday and Noon Friday.

Option -2:

Measure hourly Leq of three Hours and compute Ldn with three hourly Leq. The measurement is

preferable, if the location is exposed to moderate impact. The obtained Ldn will be slightly

underestimated, for accurate Existing Noise measurer full day Ldn.

Three Measurement will be taken during peak hours, midday and late night to early morning.

Option -3:

Ldn can be obtained with only LeqA one hour existing noise measurement, Ldn obtained will be

moderately underestimated.

Measurement between 7 am to 7 pm : Ldn Leq 2 Measurement between 7 am to 10 pm : Ldn Leq + 3 Measurement between 10pm to 7 am : Ldn Leq + 8

3.3. Analysis of Measurements and Noise Impact Criteria


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3.3.2. Project Noise vs. Distance exposure curve.

Estimation of project noise exposure at other distance on the receiver interest . The project noisevs. distance exposure curvewill cover project impact Ldn and Leq from 50 feet to 1000 meter.

DDistance 50 feet to 1000 feet.

GGround Factor.

Calculation of Ground factor:

Ldn or Leq


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3.4. Analysis of Noise impact on nearby location and for Mitigation.

Project Noise exposure and Existing noise exposure were obtained and Noise level impact around thelocation can be identified with Project Noise vs. Distance exposure curve.

Noise Impact Criteria: Reference FTA manual Section 3.1


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Example of Noise impact analysis on nearby location:

Project Noise: Ldn at 50 feet : 65 dBExisting Noise Ldn : 62 dB

Receiver interest : 1.2 Meter (3.937 feet) from Rail Top.

Ground factor (G) : 0.63

Location : Residential Buildings

Project Noise vs. Distance exposure curve:

Ldn or Leq


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Noise Mitigation:

Noise mitigation is to minimize noise pollution and noise impact on the environment.Mitigation as strongly recommended, if the Ldnof Project Noise is more than 65 dB.

As per The Noise pollution (Regulation and Control) Rules, 2000, ambient noise shouldbe less then below mentioned value.

Category of Area / Zone

Limits in dB (A) Leq

Day Time Night Time

Industrial Area 75 70

Commercial Area 65 55

Residential Area 55 45

Silence Zone 50 40

Note:


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Selection of Noise sensitive site

Measurement of Noise exposure levelSEL of Metro Train at 50 feet from

Viaduct center.

Convert Measure SEL of Metro Trainsinto SEL Reference.

Calculate Ldn or Leq (H) with SELreference and operation Characteristics

of Metro Trains.

Calculate Ldn or Leq (H) with SELf d ti

1. Existing Noise Exposure Leq (H)for

nonresidential area during Noon hours of thealternative week days.

2. Measurement of Existing Noise exposure levelin Residential area. Full day measurement ofLdn will results exact value of existing noise.Option -1:Measure full day noise exposure level Ldn. If thelocation is exposed with high external noise sources.Measurement shall be taken generally between NoonMonday and Noon Friday.Option -2:Measure hourly Leq of three Hours and compute Ldnwith three hourly Leq. The obtained Ldn will be slightlyunderestimated.

Th M t ill b t k d i k h


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3.5. Procedure to measure Project Noise and Environmental using NTiAudio meter:

NtiXL2 audio and acoustic analyzer:

XL2 is an advanced integrating sound level meter designed according to IEC 61672. XL2 is designed to measure sound level of Audio Acoustic installation (eg: Cinemas), Noise

measurement (eg: Live events, environmental noise), live sound (eg:PA), Broadcast, building

acoustics, industrial quality control and aerospace.

Refer XL2 operational manual to operate the device and to measure sound level.


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Document No RS-MN-

Document Type Routine/Periodic Test Procedure

Revision 00

Page No20 of 22


Environmental Noise Test Location, Project Noise Measurement and Existing Noise Measurement Record Sheet

Horizontal Distance of Noise level Meter /

Microphone placed from the center of track15.2 Meter

Microphone

Vertical height from

Rail Top.

App 1.5

Meter

Temperature:

DateHumidity:

Project Noise Measurement Existing Noise Measurement

Location: Location:

First Measurement

Train Set

Passing

Actual Time Measured

Leq or SELRemarks Start Time

Ldn Measured

Remarks

Approaching 50m,

Microphone

Leaving 50m,

Microphone

End Time

Second Measurement

Start Time

Ldn Measured

Remarks

End Time

Third MeasurementStart Time

Ldn Measured

Remarks

End Time

Periodic Test for Environmental Noise Test

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