I have a "pompe a eau" inside a well of 40 meters length, the water pump doesn't stop if there is no more water in the well and that causes damage to it. So I tought of using water level sensors just above the hole from where the water pump drains the water, so that when there is no more water I can turn off the circuit so that the water pump stops working.
I have a little knowledge of electronics(but good programming skill, I can program arduino or some other microcontroller without any problem).
So I have looked for water level sensors in eBay and I found this.
The problem is that the cable lenght is just 400mm, its too short for doing anything with and is this item capable of taking pressure because the "pompe a eau" is going to be 10-20 meters under the water.
Maybe this is not the right sensor for the job?