In message
<OFE6BC9C7C.8F5EC588-ON88257A6F.007581C9-88257A6F.00763614@US.Schneider-E
lectric.com>, dated Tue, 4 Sep 2012,
[email protected] writes:
I'd be surprised if 85dB(A) for 8 hours a day didn't result in profound
hearing loss over an extended time.
Surely a buzzer wouldn't be working for 8 hours continuously? Even 1
minute would be unusual. But several 1 minute exposures in an 8 hour
period would add up for the assessment of a 'safe' sound level.
And what does @ 3m mean in a workplace; 3 metres from what? There
may
be more than one source
of noise in a factory or workshop.
The 3 m distance refers to the measurement of sound level from a single
source in the absence of other sounds. But 3 m may be either within or
beyond the 'critical distance' at which the direct and reverberant sound
levels are equal. In the latter case, the sound level does not decrease
appreciably with distance (within the same space).
--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
The longer it takes to make a point, the more obtuse it proves to be.
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
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