Con'td

WEEK 5
Noise Monitoring
Date: 21/12/2016
Time: 16:21:39

MEASUREMENT
DATE: 21th DECEMBER 2016		TIME: 4.21 PM
MEASUREMENT TIME INTERVAL: 1 HOUR
EQUIPMENT
SOUND LEVEL METER MODEL: EXTECH INSTRUMENT SERIAL NO: 150105006
WEATHER CONDITION
WEATHER EQUIPMENT SERIAL NO: SM 15413297 PRESSURE (Pa): 1016 hPa		PRECIPITATION: RAINING/DRIZZLE
CLOUD COVER: CLEAR/SCATTERED CLOUD/PARTLY CLOUD/MOSTLY CLOUD/OVERCAST
AVERAGE WIND SPEED: 3 kph TEMPERATURE: 29˚C		HUMIDITY (%): 72%
DESCRIPTION AND OPERATING CONDITION OF THE SOUND SOURCE
LOCATION OF SITE: ALOR GAJAH ROUNDABOUT
DESCRIPTION OF SITE: THE ROUNDABOUT IS LOCATED BESIDES MAIN ROAD AND ALSO LOCATED OPPOSITES TO SHOP LOTS AND ALSO INDUSTRY AREA.
BUILDING GEOMETRY: SINGLE STOREY
GROUND COVER & CONDITION: TAR ROAD
PARAMETERS
HEIGHT OF MICROPHONE (Hr): 1.2 m		HEIGHT OF SOURCE (Hs): 1.46 m
DISTANCE BETWEEN SOURCE AND MICROPHONE (r): 3.54 m
ROAD TRAFFIC
# OF HEAVY VEHICLES (>3500KG) (Min 30): 74	# OF LIGHT VEHICLES (Min 30): 1268		AVERAGE SPEED: 60 km/h

So we have reached the final week which was the fifth week. On this day, at 16:21:39 we started the assessment and finished it up at 17:21:38. Below are the results that we have obtained after 1 hour of monitoring this particular session. 

Discussion
Overview

Above are the value of noise level that are taken during 1 hour period of time:

Firstly, L10 is the noise level exceeded for 10% of the time of the measurement duration. This is often used to give an indication of the upper limit of fluctuating noise, such as that from road traffic. So for the 5th week, the value of L10 is 73.3 dB. Compared to the fourth week, it decreased by 1.7 dB. Then for L50, it is the noise level exceeded for 50% of the measurement duration. Therefore the value of L50 is 67 dB. The value is slightly decreased. Next, the L90 is the noise level that is taken to be the ambient or background noise in the road traffic. The value of L90 is 61.9 dB. Compared to the fourth week, it decreased significatly by 3.1 dB. Futhermore, the value of Max dB for this particular week 90.1 dB. This is due to heavy vehicles were passing by on the road traffic. In addition, Leq is the Sound Pressure Level in dB, time-averaged level and is equivalent to the total Sound Energy over a 1 hour period of time on the road traffic. The value of Leq is 70 dB for the fifth week.