Re: [PSUBS-MAILIST] depth indicator

["Andrew Goldstein" <ag@desertstar.com>]

The defining feature of an ambient sub is that the pressure inside is equalized to the pressure outside the hull.
But there is another case where an external pressure sensor can possibly read different than an internal one.

An external sensor may be in subject to pressure variations due to flow (depending upon sensor placement, vehicle hydrodynamics, types of maneuvers being done etc.)  In which case this sensor would read differently than one inside the
hull (and possibly one placed elsewhere externally).  Most likely in all practical situations this will be negligible, but still could be detected.  There will also be a time delay since equalization is not instantaneous, but this may be very very short.


-a


-----Original message-----
From: djackson99@aol.com
Date: Fri, 29 Aug 2008 05:14:26 -0700
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] depth indicator

> Hmmmm... Not the weight of the sub. It should indicate the depth of the vent where the air is released into the surrounding water and likely a little deeper since the constant flow of air may add a few psi to the ambient cabin.? Air at the top of the cabin is at the same pressure as the air at the bottom of the cabin where it is vented to the surrounding water.? So it does not matter where the gauge is inside the cabin.
> 
> That also makes the air at the top of the cabin at a pressure higher than the water surrounding the top of the cabin. So a hatch in the top of an ambient sub seals naturally if it opens inward.? Completely opposite to a 1ATM sub.
> 
> In my case the dive computer is going to ride along outside the forward view port. There is no room for it inside and with it outside it will automatically start logging the dive when it submerges.
> 
> So what are you thinking of building?
> 
> Doug J
> www.submarineboat.com
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> -----Original Message-----
> From: David Bartsch <dbartsch2236@hotmail.com>
> To: personal_submersibles@psubs.org
> Sent: Thu, 28 Aug 2008 11:11 pm
> Subject: [PSUBS-MAILIST] depth indicator
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> ?? In an ambient submarine, if one uses a dive watch type depth indicators to give an indication of how deep He is, does this display the actual depth or will it be off a little having the additional weight of the sub working on it? One of those HMMMM thoughts...
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> ?
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> ???????????????????????????????????????????????????????????????????????????????????? David Bartsch
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> 
> Be the filmmaker you always wanted to beearn how to burn a DVD with Windows. Make your smash hit=
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