What about filling the vessel with a less compressible material. Then
you could calculate the difference between that and 1atm, and go from
there. I was thinking of a liquid...check the archives about the
submerged computer :)

Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
        -Douglas Adams

Chris Loiacono wrote:
>
> This is similar to a scuba computer that I did recently. The vessel will
> deform and change volumetrically at fairly shallow depths - this is
> something one learns
> during the earliest scuba cert training. I wouldn't want to even try to
> calibrate a system
> with a differential sensor inside the vessel.
> What max depth will your sub run at? for shallow depths (<100 ft.)I think
> the most convenient,
> reliable, and simplest solution for this may be a
> Motorola gauge type pressure sensor. According to the data sheets they are
> only for use in air,
> but since they have a fluorosilicone gel covering the chip, I have found
> that they have a
>  pretty long life in fresh water, even in chlorinated pool water. These are
> very small devices,
> approx 20mm round by 6 thick. 5V analog output models are very easily
> scaled. The device can be
> inside the sub with it's barbed fitting through the outer hull with a small
> o-ring.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body