[GreenKeys] Telephone equipment factory question

[Roy Morgan]

Here my friend Steve adds some info to his earlier reply about the  
manometer-measured noise level.  Thanks, Steve.

Roy


On Nov 1, 2008, at 9:05 PM, Steve Fick wrote:

> Hello Alf,
>
> According to page 192 of "A Textbook of Sound" by A. B.Wood (1955),  
> QC225.W6,  a device called the Richardson Manometric capsule  
> (described in Proc. Phys. Soc., May 1928) was used to measure sound  
> pressure and was calibrated against a water manometer.
>
> Converting mm of water to Pascals and Pascals to sound pressure  
> level in dB, 0.85 mm corresponds to 113 dB, the low end of the sound  
> level range for a jet plane 100 yards away.
>
> Regards,
>
> Steve Fick
> N3TE
>

Roy Morgan
k1lky at earthlink.net
529 Cobb St.
Groton NY, 13073