water level meter

[veli]

pls help me to build water level meter.the one i made uses 4 probes for empty,quarter,half and full.Now a want a better design.

[oldvan]

Can we have more insight into the dimensions of the water vessel to be measured?

Do you want to go with a simple expansion to 8 probes, or would a float and potentiometer be appropriate?

Perhaps ultrasonic rangefinder to detect depth to water?

Probe that changes capacitence as the water level increases?

At the extreme,  a lovely woman with a tape measure.  Pleasant to look at and voice output.

Many ways to approach this, but we need to know more details of the application first.

[HeliEye]

I recently designed a simple water level detector for air conditioner water drip trays in computer rooms. 
It uses stainless steel contacts, a simple mosfet detector driving another mosfet and relay combo.  I feed 12V to one of the contacts, via a 10K resistor, the other contact, when water is present, turns on the mosfet, fires the relay, giving an alarm. I see no reason why the same circuit couldn't be applied to multiple level/trigger points.

Steve

[lillbear]

Can we have more insight into the dimensions of the water vessel to be measured?

At the extreme,  a lovely woman with a tape measure.  Pleasant to look at and voice output.

Ahh what a wonderful way to know...um the watering needs.

yours

[tAhm1D]

Hi veli,
The attached circuit is self-explanatory. You can adjust this circuit according to your requirement.

[Virre]

A capacitive sensor will do the job.  There are many ways to do it, here is one.

http://www.discovercircuits.com/DJ-Circuits/capgage.htm

[nawab]

Well I made one for diesel tank. Nothing fancy but used a fuel gauge float from a car (Indian Maruti Suzuki). Interfaced the resistor to A/D input of 16F72 and had a nice bargraph display made of LEDs.