Hi rob,

You may measure dust with a optical laser system.
this can be done 2 ways,

1. Use direct light transmission (loss of light due to dust in path from
100% light setting) This is unaccurate for low concentration, but suitable
for heavy dust.

2. use scatterd light measurement (light scattered when it hits small
particles
in the air) This is accurate for small conc. of dust. Collect scattered ligt
with a lens, and cover the center of the lens to prevent direct laser light
from hitting the sensor.

good luck




>This may be a little off topic but I figure it may be of interest to
>others:
>
>I'm working on a small data collection / logging system to measure RH &
>temperature. It would be nice to also measure the amount of dust in the
>area under test.I figured with the diversity of the "list" some one may
>have done this at some stage. I have found some limited information on
>systems which use an optical method employing a laser diode but little
>other information seems available. The systems I have found output a
>mg/unit volume figure dependent on the amount of dust in the air sample.
>Any clues as to how this is done?? Linear CCD?
>
>rob
>
>

Steinar Olsen
Electronics Engineer
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Norsk Elektro Optikk A/S        Work E-Mail:  Steinar@neo.no
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