5
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCT
A
VE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
Test conditions,
Cooling : Dry-bulb temperature 27
:
Wet-bulb temperature 19
:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
COOLING
FUNCTION
45
SPL(dB(A))
LINE
Hi
NOTCH
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCT
A
VE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
Test conditions,
Cooling : Dry-bulb temperature 35
:
Wet-bulb temperature 24
:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
COOLING
FUNCTION
55
SPL(dB(A))
LINE
Hi
NOTCH
3
NOISE CRITERIA CURVES
MS-30SV-
A1
MU-30SV-
A1
OB255--1qxp 7/20/00 10:09 AM Page 5
