Ben Okopnik wrote: > On Sun, Nov 14, 2010 at 08:12:54PM -0800, Lew Hodgett wrote: > >> The problem is reliable liquid level detection which you haven't >> addressed. >> > > Lew, that's an interesting statement. What's unreliable about a > well-designed float (e.g., http://x.co/KGoQ), or for that matter, the > cycling pump that we were talking about? These seem like no-brainers. > It's not like you're working with high-viscosity materials here; it's > pretty well limited to water with maybe some oil and fuel mixed in. > What's the catch? > > >> Conductivity, Capacitance, ultrasonic, pulse radar and hydrostatic >> technologies that are either not reliable or economically affordable. >> > > OK, I can see conductivity as being of marginal use if the contacts get > coated with oil; somewhat of a ditto for capacitance, although for > slightly different reasons. What's the failure mode for ultrasonic or > pulse radar? I can't imagine radar-absorbent foam being a common > component of bilge water. :) > > I suspect that falls under the heading of "affordable". ;)
Besides I don't need a klystron in my bilge. On a totally "blue sky" project I've thought about aiming a laser into the water at an angle and having a small array of sensors properly positioned to detect the reflection. That would be trivial to construct. I'm assuming the surface of the water would remain reflective. Oil wouldn't cause a problem but a piece of debris might. To avoid debris from floating by, I could put the whole thing in a wire cage. I think I'll go back to a cycling pump for starters. I haven't measured the current in the pump so I haven't selected a MOSFET yet but I've got all the other parts. Jim. _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://liveaboardonline.com/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardonline.com/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
