Measurement of Noise in Tractors

7/21/2019 Measurement of Noise in Tractors

1/44

ARJUN

CB.EN


2/44

PHASE - I


3/44

Noise

o Noise is measured in decibels (dB) on a logarithmic scale.

o Noise means any unwanted or unpleasant sound.

o Acoustic noise can be anything from quiet but annoying to loud a

harmful.

o Sound intensity follows an inverse square law with distance from t

source; doubling the distance from a noise source reduces its

intensity by a factor of four, or 6 dB


4/44

Intermittent

TYPES OF NOISE

Continuous

Impact

E.g. : sound of the loud TV buzz when turned off and on

E.g. : TV buzz noise turned up as loud as possible

E.g. : popping of a balloon, gun shot etc.


5/44

Hearing Impairment

Sleep Disturbance

Interference with Speech Communication

Annoyance

Effects on Physiological Functions

Psychological effects

EFFECTS OF NOISE


6/44

Noise Level Allowable Exposu

85 decibels - 8 hours

90 decibels - 4 hours

100 decibels - 1 hour

105 decibels - 30 minutes

110 decibels - 15 minutes

115 decibels - 0

DAILY ALLOWABLE EXPOSURE TIMES TO N


7/44

NOISE LEVELS EXAMPLES

Equipment Noise Level

Wood Shop - 89.6 decibels avg.

Music Room - 90.1 decibels avg.

Ag/Metals - 87.6 decibels avg.

Trimmer - 92.0 decibels

Edger - 94.5 decibels

Lawn Mower - 96.4 decibels

Chain Saw - 110 decibels

Gunshot - 140 decibels

Jackhammer - 112 decibels

Tractor - 95-105 decibels

Circular Saw - 90-100 decibels


8/44

INVERSE SQUARE LAW


9/44


10/44

NOISE MEASUREMENT

o Noise can be measured by instruments based on a sound detection device

(microphone) that is sensitive to fluctuations in barometric pressure

o After appropriate amplification, frequency weighting and filtering (when used

microphone output is registered on a meter.

o The basic sound level meter contains different networks that give greater we

or importance to sounds in certain frequency ranges than in others.

o These networks are usually referred to as the A, B, and C scales


11/44

o The human ear does not respond in the same way to similar sound pressur

at different frequencies, and the "A" network of the sound level meter is inte

approximate this type of response.

o Thus noise measurements of human concern are measured by the "A" netw

and the results signified as dB(A).

Low sound pressure levels for the A -network

Medium sound pressure levels for the B-network

High levels for the C-network


12/44


13/44

AIR BORNE NOISESTRUCTURE BORNE NOISE

TRACTOR NOISE

TRACTOR NOISE

cooling fan

exhaust silence

intake etc.

Engine structure

Transmission system

Other accessories etc.


14/44

Noise Measurement at By standers position

TRACTOR NOISE MEASUREMENT


15/44


16/44

Tractor sound level measurements were

made on a chassis dyno in a semi-anechoic

room at different driving speeds to record

results inside and outside the cab.


17/44

NOISE MEASUREMENT STANDARDS

FOR AGRICULTURAL TRACTORS

IS 12180

Noise measurement at OEL (Operators Ear Le

Measurement of highest SPL at operators ear level i

including lower and higher gears.

Noise Measurement at By standers position

Measurement of highest SPL at 7.5 m distance from

of track in all gears including lower and higher gear


18/44

ISO 5131:1996

Acoustics -- Tractors and machinery for agriculture and forestry -- Measuremen

operator's position -- Survey method

ISO 7216:1992

Acoustics -- Agricultural and forestry wheeled tractors and self-propelled mach

Measurement of noise emitted when in motion

IEC 651:1979

Sound level meters.

IEC 804:1985

Integrating-averaging sound level meters.

IEC 942:1988

Sound calibrators.

IEC 1260 1995

Electro-acoustics

Octave-band and fractional octave-band filters


19/44

REFERENCE

Monazzam M. R. PhD, Nadri F. MSc, Khanjani N. PhD, Ghotbi Ravandi M. R. PhD, Na

T. MSc, Shamsi M. PhD, Akbari H. MSc, Akbari H. MScTractor drivers and bystand

in different engine speeds and gears - Iranian Journal of Military Medicine Summer 2012; 149-154

I.H Celen, S ArinNoise levels of Agricultural Tractors Pakistan Journal of Biologi

6(19): 1706-1711, 2003 ISSN 1028-8880

Yadav, P., Gaikwad, A., Badgujar, S., Y. V. Surkutwar, N. V. Karanth - "Noise Reduction

Tractor," SAE Technical Paper 2013-26-0103

European Agency for Safety and Health at Work(https://osha.europa.eu/en/sector/agri

International Standards Organisation (www.iso.org)


20/44

PHASE - II


21/44

o Noise

o Types of noise

o Effects of noise

o Daily allowable exposure times to noise

o Noise levels examples

o Inverse square law

o

Noise measurement

o Tractor noise

o Tractor noise measurement

o Noise measurement standards for agricultural tractors

o Other related standards


22/44

DRIVER PERCEIVED NOISE LEVEL

1. Tractor in drawbar - load method

2. No-load method

CONDITIONS OF MEASUREMENT

The tractor shall be unladen, i.e. without optional accessories, but shall include coolant, lubrica

and driver. The latter may not wear any abnormally thick clothing, scarf or hat. There may betractor likely to distort the noise level

The tyres shall be inflated to the manufacturers recommended pressure, the engine, transmissio

shall be at normal running temperature and radiator blinds when fitted shall be kept open du

Ref [4]


23/44

If it is liable to affect the noise level, extra equipment powered by the engine or self poweredwipers, warm air fan, power take-off, for example, may not be in operation when measureme

parts which normally operate at the same time as the engine, such as engine cooling fan, for eoperation when measurements are being made

The test area shall be in an open and sufficiently silent location; it may take the form, for instaof 50-metre radius, having a central part with a radius of at least 20 m which is practically le

section having a solid track with as flat a surface and as few gullies as possible. The track shaas possible (e.g. free of gravel, leaves, snow, etc.). Slopes and irregularities are acceptable o

noise level caused by them lie within the error tolerances of the measuring equipment

The surface of the track be such as not to cause excessive tyre noise


24/44

Meteorological Conditions

o The air temperature shall be in the range from -5 C to 30 C and the wind velocity shall not exceoperators position.

o Other meteorological conditions shall be such that they do not influence the measurements.

o The driver perceived ambient noise level due to wind or other source of noise shall be at least 10

noise level of the tractor.

All measurements on the given series shall be carried out on the same track

All readings of the sound level meter shall be taken with the time weighting S.

If a vehicle is used for measurements, it shall be towed or driven at sufficient distance from the trainterference. During measurements no object interfering with the measurements or reflective surfac

in 20m of each side of the test track and less than 20m to the front or rear of the tractor. This con

considered fulfilled if the variation in noise level is with in the tolerance error; if not measurement for the duration of interference.


25/44

METHOD OF MEASUREMENT

The microphone shall be located 250 20 mm to the side of the centre plane of the seat, the s

which the higher level of noise is encountered. The axis of microphone shall be horizontal and t

diaphragm shall face forward and centre of microphone shall be 700 20 mm above the sea

defined in IS 11113:1999/ ISO 5353: 1995) and 100 20 mm forward of that point. Excess

microphone shall be avoided.

The tractor shall travel along the same section at the same test speed at least three times for a


26/44

All openings (e.g. Doors, windows) in tractors having a closed series produced cab structure sha

an initial series of measurements.

During a second series of measurements they shall be left open, provided that when open they

safety hazard, but fold-down or fold-up windscreens shall remain closed.

Noise shall be measured at the maximum rpm using slow sound level metre response i.e. in the speed nearest to 7.5 kmph at the rated rpm. The tractor shall be unladen when measurements


27/44

NOISE ME SUREMENT T BY ST NDERS POSITION

CONDITIONS OF MEASUREMENT

Measurements shall be made on unladen tractors in a sufficiently silent and open areaand wind noise at least 10 dB (A) below the noise being measured).

This area may take the form, for instance, of an open space of 50 metre radius having

of at least 20 metres radius which is practically level; it may be surfaced with concrete

similar material and may not be covered with powdery snow, tall grass, loose soil or as

The surface of the test track shall be such as not to cause excessive tyre noise. This c

only to measurement of the noise made by tractors in motion.


28/44

Meteorological Conditions

o The test shall not be carried out in adverse weather conditions which are likely to affect the mea

o The wind velocity measured at 1.2 m above ground level shall not exceed an average value of over a 30 s period, or a maximum value of 8 m/s during the test period.

o For wind speeds in excess of 1 m/s, a microphone windscreen shall be used; appropriate compe

effects of its use shall be allowed for in the calibration

No person other than the observer taking the readings from the apparatus may remain near themicrophone, as the presence of spectators near either the tractor or the microphone may conside

readings from the apparatus. Marked fluctuations of the pointer which appear to be unrelated characteristics of the general sound level shall be ignored in taking readings.


29/44

Conditions of Agricultural Tractor

o The Agricultural Tractor being tested shall comply with the manufacturers specifications and shall baccordance with published instructions. It shall be unladen and unballasted and, except in the case

machines, be without trailer or semi-trailer.

o Immediately before the test, the engine shall be brought to its normal operating temperatures.

o If the Agricultural Tractor is fitted with more than two-wheel drive. It shall be tested in the drive wnormal road use.

o The Agricultural Tractor shall be fitted with tyres in accordance with the manufacturers specificatio

not be more than 50 % worn.

o During the test, only those components required for operation on the track shall be in operation.


30/44

METHOD OF MEASUREMENT

At least two measurements shall be made on each side of the tractor. Preliminary measurements m

adjustment purposes but shall be disregarded.

The microphone shall be situated 1.2 metres above ground level at a distance of 7.5 metres from

tractors centre line, CC, measured along the perpendicular PP to that line.

Two lines AA and BB, parallel to line PP and situated respectively 10 metres forward and 10 me

line, shall be marked out on the test track. Tractors shall approach line AA at a steady speed, as throttle shall then be fully opened as rapidly as practicable and held in the fully opened position

the tractor crosses line BB; the throttle shall then be closed again as rapidly as possible.

The maximum sound level recorded shall constitute the result of the measurement.

The test speed shall be three-quarters of the maximum speed which can be attained in the highesmovement


31/44


32/44

This study was done to investigate the noise level produced by M-650 Romanian tractor in bo

and mobile states in two positions of the driver's ear and the bystanders. It was conducted in university of Kerman, Iran, in 2011.

The features of Romanian tractor (M-650) used for the study

1. Tractor drivers and bystanders noise exposure in differen

engine speeds and gears


33/44

Engine speeds of 850 and 1700 rotations per minute was selected.


34/44

g p p

Measuring noise level in both positions of the driver's right ear and that of bystanders was d

To measure the noise level at the driver's right ear position, a sound-measuring microphone wcm from the ear.

To measure the noise level in the bystanders position, a sound-measuring microphone was inse

side within 10 meters from Commencement Centre (CC) and within 7.5 meters from central linaxes of the tractor's tires) and at a height 1.2 meters from the ground.

The noise level around the tractor (in engine speeds of 850 and 1700 rpm) in stationary stat

The sound-measuring device was inserted within 50 cm from the tires' axes, parallel to the gr

and left sides of the driver and at a height of 50 cm.

Measuring was also done in the position of exhaust pipe within 20 cm from it. The angle betw

microphone and the vertical axes of exhaust was selected 45 degrees.


35/44

The average noise level in the surroundings of Romanian tractor in fix state in different e

(without the use of splitting gear)

Results

Results of frequency analysis in the position of tractor's Exhaust emissions in fixed state


36/44

Results of frequency analysis in the position of tractor s Exhaust emissions in fixed state

engine speeds


37/44

The average noise level in different gears and engine speeds in the position of the driv

in moving tractor


38/44

The average noise level in different gear and engine speeds of moving tractor in the b

position


39/44

Difference in average noise level in different gears and engine speeds in the position of th

and bystanders for the moving tractor

Results of frequency analysis in the driver's ear position in different gears for the engine speed

i


40/44

moving tractor


41/44


42/44

Position near the exhaust had the highest noise exposure and an increase in engine speed fr

1700 rpm led to an increase in noise for the drivers ear from an average of 5.8 to 9.3dB a

bystanders from an average of 2.3 to 10.3dB.

When the tractor is moving, at 850 rpm the drivers exposure to noise in all gears is less than

1700 rpm the noise level is higher than the ACGIH standard and controlling measures seems

The mean sound level at lower frequencies was higher than middle and high frequencies

Conclusions


43/44

[2] Monazzam M. R. PhD, Nadri F. MSc, Khanjani N. PhD, Ghotbi Ravandi M. R. PhD, Nadr

MSc, Shamsi M. PhD, Akbari H. MSc, Akbari H. MScTractor drivers and bystanders n

different engine speeds and gears - Iranian Journal of Military Medicine Summer 2012, V

149-154

[1] I.H Celen, S ArinNoise levels of Agricultural Tractors Pakistan Journal of Biologica

6(19): 1706-1711, 2003 ISSN 1028-8880

[3] Yadav, P., Gaikwad, A., Badgujar, S., Y. V. Surkutwar, N. V. Karanth - "Noise Reduction on

Tractor," SAE Technical Paper 2013-26-0103

[4] AIS-115 (Part 1) ,Driver-Perceived Noise Level of Agricultural Tractors - Method of Meas

[5] AIS-115 (Part 2) ,Permissible Sound Level at Bystander of Agricultural Tractors - Method


44/44

Documents

Measurement of Noise in Tractors