407750 Datasheet, PDF (7/8 Pages) Extech Instruments Corporation. – Digital Sound Level Meter

Reference Information
Frequency Weighting Characteristics
Frequency (Hz)
31.5
63
125
250
500
1k
2k
4k
8k
A Weighting
-39.4dB
-26.2dB
-16.1dB
-8.6dB
-3.2dB
0dB
+1.2dB
+1dB
-1.1dB
C Weighting
-3dB
-0.8dB
-0.2dB
0dB
0dB
0dB
-0.2dB
-0.8dB
-3dB
Tolerance (IEC 651 Type 2)
±3dB
±2dB
±1.5dB
±1.5dB
±1.5dB
±1.5dB
±2dB
±3dB
±5dB
Typical A-Weighted Sound Levels
50HP Siren (100')
Jet takeoff (200')
Riveting machine
Subway (20')
Pneumatic drill (50')
Vacuum cleaner (10')
Large store
Small office
Night residential area
Whisper (5'0)
Threshold of hearing
dB
140
130
120
110
100 Chain saw
90 _{Boiler room}
80 _{Freight train (100')}
70 _{Speech (1')}
60 _{Large Office}
50 _Residence
40
30
20 ^{Sound studio}
10
0
7
Model 407750 Version 2.1 February 2004