AVR-Chat

Campbell Scientific makes a "bubbler" to measure water depth. They get  
a good price for it, also.

Jim Wagner
Oregon Research Electronics

On May 13, 2009, at 6:41 PM, Robert Tilden wrote:

>
>
> Besides the ultrasonic sensor there are a number of other methods..
>
> A donut shaped float incorporating a magnet which rides up and down  
> around a
> magnetostrictive line. One sends a pulse down the line and measures  
> the
> return from the magnetic float location. Very accurate.
>
> A donut shaped float incorporating a magnet which rides up and down  
> a track
> with embedded reed switches.
>
> As has been mentioned, a capacitive strip line.
>
> A weighted float attached to a counterweighted (or spring loaded)  
> cable
> which turns an encoder as the float travels up and down. Also very  
> accurate
>
> Similar to the capacitive sensor, a resistive sensor (for conductive
> fluids). The higher the level, the less the resistance.
>
> An air bubbler. Sense the pressure of the air line while slowly  
> bubbling
> said line at the bottom of the tank. The sensor could be above the  
> liquid
> level so as not to be harmed by a pressure failure.
>
> Etc...
>
> -----------------------------------
> Bob Tilden, tilden@northwestern.edu
> High Energy Physics Group
> Northwestern University
>
> -----Original Message-----
> From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On  
> Behalf
> Of kernels_nz
> Sent: Wednesday, May 13, 2009 7:33 PM
> To: AVR-Chat@yahoogroupscom
> Subject: [AVR-Chat] Re: Sensor
>
> Back when I was at Uni a few years ago, one of the students had a  
> project to
> electronically measure the water level in a plastic tank. Best way I  
> have
> seen this done is run two parallel metal plates along the depth of  
> the tank
> and then look at the change in capacitance between the two plates  
> based on
> the amount of water between the plates. As the water level dropped,  
> the
> capacitance would decrease because the relative permeability of  
> water is
> higher than air . . . (Hope I remembered all this correctly) Set  
> this up as
> a oscillator with frequency based on capacitance and you have a  
> varying
> output frequency based on the water level.
>
> Hein B
> Auckland, New Zealand.
>
> --- In AVR-Chat@yahoogroups.com, "Brian" <blue_eagle74@...> wrote:
> >
> > I think the best non-movement sensor would be a presure sensor at  
> the
> bottom of the tank. No moving parts and it can be sealed. So it could
> measure many liquids.
> >
> > Brian
> >
> > --- In AVR-Chat@yahoogroups.com, Muhammad Amiruddin  
> <amiruddin.muhammad@>
> wrote:
> > >
> > > Dear all,
> > >
> > > please help me,
> > >
> > > i want make project for measuring the level of water on the tank  
> that
> approximately 15 m high. what senssor that i should use ?
> > >
> > > Is there any ultrasonic senssor wich can measure range until 15  
> m ?
> > >
> > > rgds,
> > >
> > > 4mir
> > >
> > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
>
> ------------------------------------
>
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