I want to make a water level sensor (not just on/off but 1 or 3 or 5 inches and everything in between). Well the simplest method would be to use several switches on different depths or just exchange the switches with "loose" wires in the water and add voltage to the water. But I thought of something different. Since I have no idea if this works or how it is called, I had no luck googling it. Imagine a pcb with very fine horizontal copper traces. Every trace is connected to the upper trace on one end, and to the lower on the other end. So it is like an "S". So I would put this pcb in water, and add voltage to the top. At the bottom of the pcb, I would add a wire going to an analog input. I imagine the electricity "flows" down the traces, and as soon as it reaches the water level, it would take the shortest way to the bottom, which is obviously the water. So I would imagine that the lower the water, the higher the resistance and the lower the voltage at the analog input. I think this effect will be very weak and I have no idea how to design the complete circuit.
Can you help me? Any ideas and links are appreciated.