Underwater ROV‎ > ‎Electronics‎ > ‎

Water sensors

I'm thinking that it'd be good information to have to know if the submarine springs a leak.  To that purpose, I'm going to setup three water sensors.

I started off looking at the directions found here:
However, the schematic says any NPN transistor, but I think they must have different activation voltages.  After trying two different type of resistors (not the ones listed), I bought a 2N4401.  I modified the circuit by reversing the voltage and removing the LED; so that transistor emitter feed would be feeding voltage to an analogue pin on the arduino.   I also used a 100k trim-pot.

The testing setup.

The sensor setup.  I'll probably have rods run the length of the bottom of the main housings.  The IC holder is for the Light sensor, which I am going to install on one of the water sensors.