[pianotech] New Classes for the 2011 PTG Institute in Kansas City

[Tom Rhea, Jr.]

Bravo, Diane.  You are absolutely correct.  A 3db increase translates to a
doubling of sound pressure level while a 3db decrease would mean a reduction
by 1/2 of sound pressure level.  Decibels, or tenths of a Bell, are based on
logarithmic tables.  In electronics, 0dbm (zero dbm) is an absolute
measurement of power or sound referenced to 1 milliwatt (mw) of power, hence
a 3db increase from 0dbm would be 2mw of power.  Any Navy Electronics
Technician or Sonar Technician will understand this simple concept.  Leave
it to the government (read OSHA) to screw up their own tables.

Tom Rhea, Jr.
Rhea Piano Service

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Diane Hofstetter
Sent: Tuesday, July 06, 2010 1:55 PM
To: pianotech at ptg.org
Subject: [pianotech] New Classes for the 2011 PTG Institute in Kansas City


 
> Possibly a similar
>arrangement can be made with some OSHA educators in the Kansas
City>area....
>Patrick Draine

 
The problem with OSHA, at least as far as hearing is concerned, is that it
is politically motivated.  Therefore OSHA tells you that a 5dB exchange rate
is ok, whereas science and the rest of the world know that a 3dB exchange
rate is true.  
 
Therefore, OSHA says you can stay in 85dB of noise for 8 hours, 90dB for 4
hours, 95 for 2 hours, 100dB for 1 hour, 105dB for 1/2hour.
 
BUT, actually, the numbers are:  85dB for 8 hours, 88dB. for 4 hours, 91dB
for 2 hours, 94dB for 1 hour, 97dB for 1/2hour, 100dB for 1/4 hour, 103dB
for 7 1/2 minutes.....
 
Not only that, the 85dB 8 hour starting point is the level that still allows
15% of the population to get hearing damaged from the noise.
 
 
We need specific help in our piano technical work, not generic governmental
committees' rules to guide us to protect ourselves.  
 
As far as the chemicals are concerned, there are a number of them we use
that we don't even know the components of, much less whether they might have
a deleterious effect on our health.  If Roger Wheelock, or another chemist
who understands our methods and materials can sort this all out, we will be
very lucky indeed!


Diane Hofstetter 		 	   		  =