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The dB
scale of sound pressure levels is logarithmic. Every additive increase of 20 to
the value increases the sound by a multiplicative factor of 10.
For reference, normal conversation is in the 70 - 85 dB range. SPLs above 90 dB
can cause hearing loss through prolonged exposure. The threshold of pain is 115
to 120 dB, causing "ringing in the ear" and some immediate damage.
Some live concerts approach these levels!
Radial arm saw running
freely.........................98 dB
...........................cutting wood.......................108
Panel saw........................................................94
Band saw.....running freely...............................80
.....................cutting wood...............................88
.....................cutting metal..............................96
Belt sander...running freely..............................82
.....................sanding wood..............................90
.....................sanding metal.............................100
Drill press......running freely..............................66
Lathe................................................................66
Milling machine................................................64
Measurements made with General Radio
1551-C Sound-Level Meter placed at approximate user head distance.
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