Smoke/Soot Production Measurements

[philio]

Hi all,

Many reference material records soot production by units m2., derived
from (optical obscuration) x (airflow) recorded in a calorimeter.

FDS appears to be capable of also adding in a device like this, using
extinction coefficient to find smoke obscuration for the purpose of
measuring smoke production.

However this seems like a bit of a variable and I am wondering if
there is a simpler solution in FDS.
Has anyone attempted this ?
My goal is to measure the smoke production in m2.

Thanks
Philip

[Kevin]

We would rather leave this up to you. FDS has a default value of the
MASS_EXTINCTION_COEFFICIENT of 8700 m2/kg. Just multiply by this value
to get comparable values to what a calorimeter produces. Personally,
reporting smoke production and yield in units of m2/s and m2/kg,
respectively, is unnecessarily confusing. I see nothing wrong with
reporting these measurements in understandable units like kg/s and kg/
kg along with the value of the mass extinction coefficient used to
derive these values from the obscuration measurement. That's just my
opinion, but I'd prefer that FDS not contribute to the practice of
reporting that currently exists. If we want fire protection
engineering to be understood by others outside the field, we should
use more understandable nomenclature.