14 Jul
1998
14 Jul
'98
3:01 a.m.
Why not use a radioisotope and a metal plate, like in a smoke detector?
I think the element could be removed from the smoke detector and wired
into a different circuit that triggers on dust.
I don't know how it works. For high particle counts (like your vacuum
cleaner), I would guess you could use light scattering. I can't believe
that would work at class 100 levels, though.
-tony
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