AVR-Chat

My water pressure sensor has only failed due to
freezing of the water.  My house fresh water tank
is only 4' tall, and not quite cylindrical, so the pressure
reading is not quite linear with volume.
I use a DVM always-on to read millivolts: 100mv
empty, 500 mv full. 
The major problem has been variation with atmospheric
pressure, which was only improved slightly by changing
the sensor from gage to differential.


Philippe Habib wrote:
>
>
> I worked on a lab device that used this system and water droplets
> still found their way into the sensor and toasted it. The solution
> was an expensive custom gauge protector. So if you use this approach,
> you need to be sure the mechanical stuff is 100% taken care of properly.
>
> On May 13, 2009, at 8:09 AM, Bruce Parham wrote:
>
> > I like the method used in most washing machines where they place a
> > pressure
> > sensor above the liquid and run an open ended tube down to the
> > bottom. That
> > keeps the sensor and electronics dry.
> >
> > Given that water pressure = 1.363 PSI/m, a 15 m water head will
> > produce
> > 1.363 PSI/m x 15 m = 20.45 PSI. A 25 to 30 PSI full scale sensor
> > should do
> > the trick.
> >
> > Bruce
> >
> >
> >>> 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 
> <mailto:AVR-Chat%40yahoogroups.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
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>
>