Dear Karl, and All,
The Dent Dictionary of Measurement lists two entries that might be relevant
to your request. Both the unit and the formula were named for the American
physicist Wallace Sabine (1868-1919).
'sabin
[physics] Obsolete unit of sound absorption (by architectural materials),
equal to the absorption of an open window of 1 square foot area (0.0929
square metre) for low frequency sound waves. (The absorption of an open
window was assumed to be total, or perfect.'
'Sabine reverberation formula
[physics] For an enclosure, the reverberation time of a sound equals 0.16
times the volume (in cubic metres) divided by the total absorption in the
enclosure (that is, the product of the absorption coefficient and the
surface area in square metres).'
It seems to me that the 'absorption coefficient' would be a dimensionless
coefficient that technically would not have a unit, but someone has given it
the name sabin to honor Wallace Sabine. I suppose it's a bit like radians
and steradians, which are both ratios that technically don't need unit
names.
My guess would be that we could think of an anechoic chamber as having an
absorption coefficient of say 0.98; and we could call this 0.98 sabin. On
the other hand if we designed a strongly reverberant room, it might have an
absorption coefficient of something like 0.1; and we could call this 0.1
sabin.
If my guess is correct then you could use the sabin number as the absorption
coefficient is SI as it was in ifp units - just ignore the unit altogether.
Cheers,
Pat Naughtin CAMS
Geelong, Australia
on 2001/03/31 02.48, Karl G. Ruling at [EMAIL PROTECTED] wrote:
> Does anyone know the SI or metric equivalent of the sabine? The sabine is
> the unit of sound absorbtion of one square foot of a perfect sound absorber
> (an open window, e.g.). I can't find the sabine listed in IEEE/ASTM SI 10
> or in the NIST guide.
> Best regards,
> Karl G. Ruling
> Technical Standards Manager
>
> The Entertainment Services & Technology Association
> 875 Sixth Avenue, Suite 2302
> New York, NY 10001
> +1-212-244-1505
> Fax: +1-212-244-1502
>
