Request for water level sensors circuit

[WinderMan]

request for water level sensors circuit!

anyone got the water level sensors circuit?
can share with me?
really appreciate !

 

[berkeman]

anyone got the water level sensors circuit?
can share with me?
really appreciate !

There are lots of ways to sense a water level. You need to be much more specific about the application in order for us to help you. Is this for work, or a school project, or a school paper?

 

[WinderMan]

There are lots of ways to sense a water level. You need to be much more specific about the application in order for us to help you. Is this for work, or a school project, or a school paper?

i need to sense the water level of a tank..when the water level reach certain low level then will sense it...its a part of my project..because i just learn some basic on electrical circuit..i really don't have any idea about this...really appreciate if u can help!~~~

 

[berkeman]

Simplest would be a float placed at the low water level, mechanically connected to a switch that is above the high water level (so it doesn't have to be a waterproof switch).

 

[jstippey]

We used two conductors that were separated and then machined to fit in a piece that was water tight on the back-end. Applied 5V across the terminal in series with a resistor and measured the Voltage across the resistor. When the resistor had voltage, water is there completing the circuit and when the resistor has no voltage, there is no water and open circuit.

 

[berkeman]

We used two conductors that were separated and then machined to fit in a piece that was water tight on the back-end. Applied 5V across the terminal in series with a resistor and measured the Voltage across the resistor. When the resistor had voltage, water is there completing the circuit and when the resistor has no voltage, there is no water and open circuit.

That would depend on the water being resonably conductive, which is not always the case.

 

[jstippey]

Yeah, if you are using deionized water it wouldn't work, but in this application I highly doubt that they are even considering using deionized water. This would work fine in there sitiuation (unless using deionized) and is really cheap and easy to do.

 

[rolerbe]

Are you trying to sense binary presence/absence of water (above a certain level) or measure the level of the water in the tank? Different problems.

 

[stewartcs]

We used two conductors that were separated and then machined to fit in a piece that was water tight on the back-end. Applied 5V across the terminal in series with a resistor and measured the Voltage across the resistor. When the resistor had voltage, water is there completing the circuit and when the resistor has no voltage, there is no water and open circuit.

The conductors will corrode away quickly with that design. The easiest and cheapest way is like Berkeman recommended. A more expensive way would be a proximity sensor and a stilling tube.

CS

 

[zeitghost]

There's a truly wonderful thread on the eng-tips site about depth of water sensing... down a borehole.

Definitely worth a read if you're bored sometime.

 

[berkeman]

Hi sir!thanks for helping me to solve the problem of water level sensors..But I am not very understand how the float works..is it the switch will detect the float??

Put a float down at the level in the tank that you want to detect, and connect it with a light rod (that the float can lift) up to a switch above the highest level of the water. Constrain the float and rod to only be able to move a little bit vertically -- just enough to throw the switch. Support the whole assembly mechanically (just attache it well to the side of the tank at the top), and you're ready to go.

 

[Redbelly98]

These are commonly called float switches and are often part of a water pump, when the pump is meant to turn on/off automatically when the water level is above/below some level.

http://www.google.com/search?hl=en&safe=off&q=float+switch&btnG=Search

A similar idea is at work inside most household toilet tanks, even though it's not an electrical switch that is being activated.