Service manual

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OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
63 125 250 500 1000 2000 4000 8000
BAND CENTER FREQUENCIES, Hz
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
SPL(dB) LINE
56
PU42EK2 PU42EK7
PU42EK21 PU42EK71
PU42EK72
3.3ft
3.3ft
MICROPHONE UNIT
GROUND
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