59
Sound Level
Sound Pressure Level
Model Speed
1/1 Octave A-weighted Sound Pressure Level (dB, ref 20µPa)
Overall
(dBA)
Noise
Criteria
125Hz 250Hz 500Hz 1kHz 2kHz 4kHz 8kHz
FTV28A
High
35 38 35 33 29 21 11 38 32
Med
31 34 30 28 23 16 10 33 26
Low
30 32 28 25 20 12 10 30 23
Quiet
29 29 25 24 18 10 10 28 22
NC Curve
0
10
20
30
40
50
60
70
80
90
63 125 250 500 1k 2k 4k 8K
NC-40
NC-50
NC-60
NC-30
NC-20
NC-70
NC-40
NC-50
NC-60
NC-30
NC-20
NC-70
NC-40
NC-50
NC-60
NC-30
NC-20
NC-70
QUIET (Q)
LOW (L)
MEDIUM (M)
HIGH (H)
OCTAVE BAND CENTER FREQUENCY (Hz
PPROXIMATE
HRESHOLD HEARING FOR
ONTINUOUS NOISE
3D122799