10
SOUND PRESSURE LEVELS
5
5-1. Sound pressure level
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
70.0
63
125
250
500
1k
2k
4k
8k
NC-60
NC-50
Approximate minimum
audible limit on
continuous noise
NC-40
Octave band center frequencies (Hz)
NC-20
NC-30
High
Middle
Low
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
70.0
63
125
250
500
1k
2k
4k
8k
NC-60
NC-50
Approximate minimum
audible limit on
continuous noise
NC-40
Octave band center frequencies (Hz)
NC-20
NC-30
High
Middle
Low
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
70.0
63
125
250
500
1k
2k
4k
8k
NC-60
NC-50
Approximate minimum
audible limit on
continuous noise
NC-40
Octave band center frequencies (Hz)
NC-20
NC-30
High
Middle
Low
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
70.0
63
125
250
500
1k
2k
4k
8k
NC-60
NC-50
Approximate minimum
audible limit on
continuous noise
NC-40
Octave band center frequencies (Hz)
NC-20
NC-30
High
Middle
Low
(External static pressure 60 Pa)
(External static pressure 75 Pa)
(External static pressure 100 Pa)
(External static pressure 150 Pa)
Ceiling concealed
5-2. NC curves
PEA-RP200WKA
HWE17030.qxd 17.11.9 16:28 Page 10