Table 1
WECS Noise Limits at Residential Receivers
| ||||
---|---|---|---|---|
Daytime 7:00 a.m. to 7:00 p.m.
|
Evening 7:00 p.m. to 10:00 p.m.
|
Nighttime 10:00 p.m. to 7:00 a.m.
| ||
A-weighted level (dB)
|
45
|
40
|
35
| |
C-weighted level (dB)
|
63
|
58
|
53
|
Δ, difference
|
<3
|
3-4
|
5-6
|
7-10
|
>10
| |
---|---|---|---|---|---|---|
K, correction (dB)
|
Notes 2, 3
|
3
|
2
|
1
|
0
|
Notes:
| ||
---|---|---|
1.
|
This table provides a simple correction to measurements of WECS
sound and in the presence of the background. For example, the sound
of a WECS (along with the background sound which is always present)
is measured as 40 dBA, and the background sound level alone (without
the WECS) is measured as 34 dBA. Then Δ, the difference in decibels,
is six dB (first row, third column), and the corresponding correction
shall be 2 dB (second row, third column). That is, two dB shall be
subtracted from the measured 40 dBA level, and it is adjusted to and
reported as 38 dBA. The same procedure is followed in each band for
one-third-octave-band data.
| |
2.
|
When using directly measured A-weighted levels, if the difference
between the WECS sound level (plus background sound level) and the
background sound level alone is less than three dB, then it shall
not constitute a violation of this chapter.
| |
3.
|
When using measured one-third-octave-band data, if the difference
between the WECS sound pressure level (plus background sound pressure
level) and the background sound pressure level alone, each in the
same one-third-octave band, is less than three dB, then the WECS level
for that one-third-octave band shall be set to zero.
|