Service manual

7
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 35: Wet-bulb temperature 24:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
52
SPL(dB(A)) LINE
High
FAN SPEED
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
MU-A18WV-
E1
MU-A24WV-
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
55
SPL(dB(A)) LINE
High
FAN SPEED
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
MU-A30WV-
E1
OUTDOOR UNIT
MICROPHONE
1m
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
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
Test conditions,
Cooling : Dry-bulb temperature 35: Wet-bulb temperature 24:
53
SPL(dB(A)) LINE
High
FAN SPEED
OB326A-1.qxp 04.2.9 10:41 AM Page 7