5
NOISE CRITERIA CURVES
4
90
80
70
60
50
40
30
20
10
63 125 250 500 1000 2000 4000 8000
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
Test conditions,
Cooling : Dry-bulb temperature 27: Wet-bulb temperature 19:
47
SPL(dB(A)) LINE
High
FAN SPEED
Heating : Dry-bulb temperature 20: Wet-bulb temperature 15.5:
MSH-A30WV-
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 27: Wet-bulb temperature 19:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
42
SPL(dB(A)) LINE
High
FAN SPEED
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
FAN SPEED
Heating : Dry-bulb temperature 20: Wet-bulb temperature 15.5:
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
MSH-A18WV-
E1
MSH-A24WV-
E1
INDOORUNIT
WALL
MICROPHONE
0.8m
1m
OB321-1.qxp 03.11.13 4:03 PM Page 5