Hello Robb,
Just thinking out loud here.
A large electret sheet, (screen over the lot, ground, electret, signal ele=
ctrode, dielectric,
ground) with amplification built in and place a dome of expanded polypropel=
ene or similar
for waterproofing and some kind of skin resistant to salt and uv / thin ure=
thane coat? -
Such a construction would perhaps be 1" thick most of that is the turbulenc=
e buffering
layers...
PVDF Coax cable would be one example, although you'd need plenty of amplifi=
cation.
Reason I mention the above is Ive recently I made a flat sensor (100 x 80 x=
2 mm) Its
response is dc to > 15 Khz covered in Silicone rubber, its constructed with=
copper mesh,
nylon and emfit polymer electret. Its currently minus 12C here so Ill give =
you a report if it
works outside, ive not tested it in such conditions..
-MIke.
--- In "robb_nichols" <> wrote:
>
> I am working on a project to provide extremely weatherproof,
> permanently-mounted mics for use on the exterior of sea-going vessels.
> I have built a prototype that I believe can withstand long-term
> exposure to environmental extremes, including ice, salt spray and UV
> exposure. This is possible due to the limited demands for fidelity
> and a bandwidth of less than 1KHz.
>
> I'm bringing this to the group because I suspect that, collectively,
> you might have some insights on windscreen design. To build a wind
> (and splash) screen that is effective in a twenty-knot wind that will
> shed water, so as not to ice up or loose its effectiveness or
> significantly attenuate the sound is no easy task. Furthermore, it
> has to be substantial enough to withstand the forces that be and UV
> exposure for at least a year. Is this preposterous, or might anyone
> have any relevant experience to share.
>
> I think that it is reasonable to expect some maintenance during use in
> a snowstorm, for instance. But ideally, I build something that just
> listens without constant attention.
>
> The mic is mounted vertically and has a recessed diaphragm. Inside
> this recession is a baffle and a small foam wind screen. I have
> considered just wrapping a fibrous nylon cover around the mic, but
> this isn't as effective as I'd wish. I wonder if I could make a thin
> waterproof-breathable (such as GoreTex)shell and put a furry or
> fibrous filling within?
>
> I have reviewed the discussion from November about using hogshair or
> nylon buffing pads to break up water impacts. Has anyone seen what
> happens to this in freezing weather?
>
> Any ideas or information gained from practical experience will be
> sincerely appreciated!
>
> Regards, Robb
>
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