24
PLA-A18BA
NOTCH SPL(dB)
LINE
High
32
Medium1
31
Medium2
29
Low
28
OCT
A
VE
B
AND SOUND PRESSURE LEVEL,
dB (0 dB = 0.0002 bar)
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
BAND CENTER FREQUENCIES, Hz
NOISE CRITERION CURVES
9
PLA-A36BA
NOTCH SPL(dB)
LINE
High
40
Medium1
37
Medium2
34
Low
32
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
BAND CENTER FREQUENCIES, Hz
OCT
A
VE
B
AND SOUND PRESSURE LEVEL,
dB (0 dB = 0.0002 bar)
UNIT
5ft
MICROPHONE
CEILING
9-1. INDOOR UNIT
PLA-A30BA
NOTCH SPL(dB)
LINE
High
34
Medium1
32
Medium2
30
Low
28
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
BAND CENTER FREQUENCIES, Hz
OCT
A
VE
B
AND SOUND PRESSURE LEVEL,
dB (0 dB = 0.0002 bar)