8
NOISE CRITERIA CURVES
4
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
BAND CENTER FREQUENCIES, Hz
Test conditions,
Cooling : Dry-bulb temperature 27: Wet-bulb temperature 19:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
42
SPL(dB(A)) LINE
High
NOTCH
Heating : Dry-bulb temperature 20: Wet-bulb temperature 15.5:
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
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
BAND CENTER FREQUENCIES, Hz
Test conditions,
Cooling : Dry-bulb temperature 27: Wet-bulb temperature 19:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
45
SPL(dB(A)) LINE
High
NOTCH
Heating : Dry-bulb temperature 20: Wet-bulb temperature 15.5:
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
MSH-18RV-
E1
MSH-24RV-
E1
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
BAND CENTER FREQUENCIES, Hz
Test conditions,
Cooling : Dry-bulb temperature 35: Wet-bulb temperature 24:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
52
SPL(dB(A)) LINE
High
NOTCH
Heating : Dry-bulb temperature 7: Wet-bulb temperature 6:
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
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
BAND CENTER FREQUENCIES, Hz
Test conditions,
Cooling : Dry-bulb temperature 35: Wet-bulb temperature 24:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
53
SPL(dB(A)) LINE
High
NOTCH
Heating : Dry-bulb temperature 7: Wet-bulb temperature 6:
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
MUH-18RV-
MUH-18RV-
E2
E1
MUH-24RV-
E1
OB272-1.qxp 02.1.26 1:22 PM Page 8