Hi-
Howabout something that changes its resistance with moisture - maybe a
piece of black electrically conducting foam?
David

cdb wrote:

> I'm looking for suggestions for making a rain sensor using Infra- Red
> techniques.
>
> So far I've tried using a TIL139 emitter/detector package with very
> little success and I've tried matched Schmidt trigger detector and
> emitter form QT now Fairchild.
> I have had better success with this except it only works face on
> placing emitter and detector at 45 deg to each other with glass
> perpendicular to both no result at all whether wet or dry.
>
> Should I perhaps try a modulated approach - if I wanted a mud spatter
> detector then no problems both setups work.
>
> Failing this I thought of trying a different tack - Piezo sensor to
> detect rain dropping on it -
>
> This will be going to a PIC has anyone any other suggestions
>
> Thanks
>
> Colin
> --
> cdb, cdb@barnard.name on 31/03/2002
>
> --
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--
David Harris
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