Honda G100K2 Applications Manual page 37

NOISE
SOUND POWER LEVEL: L
According to EC regulations, sound level of machines for outdoor use is expressed as sound power level L
dB(A).
L
WA
L = sound power level of the source tested in dB(A)
WA
L = the surface sound pressure level, expressed in dB(A) : logaritmic average of a minimum of 6
Pam
S = 2 π r²
R = the radius of the measuring hemisphere
Where r = 4 m 10 log
r = 7m
r = 10m
r =16m
S = standard surface
0
K = correction term for the test area expressed in dB(A).
CORRECTION FACTORS
•
Extraneous noise
The correction K in dB which shall be added to the average sound pressure level in dB(A).
Difference (in dB) between the sound pressure level
calculated when the sound is operating and the sound
pressure level due to extraneous noise alone
•
Others
Another correction factor K indicates the acoustic properties of the test area.
If the ground surface of the test area is rigid and made of concrete or non-porous asphalt and if there are no
reflecting objects on the measuring site, there is no need to determine any environmental constant.
WA
= L + 10 log S + K
PAm 10
S
o
S = 20 dB(A)
10
S
O
- - = 25 dB(A)
- - = 28 dB(A)
- - = 32dB(A)
Less than 6
6
7
8
9
10
more than 10
measurements.
Correction K in dB
No valid measurement
1
1
1
0.5
0.5
no correction
- 36 -
in
WA