Affordable Water Detector for Plastic Tanks - Expert Tips

[AR1234]

I'm new to the forum, and will much appreciate your advice.
Looking to build a cheap water detector, that will not change the chemistry of the water.
It should simply indicate if water is touching it (if water reach a certain level in a tank made of plastic).
Many thanks
Al

 

[Danger]

Hi, AR.
Although I don't know the scale of your project, a simple float switch should suffice. As long as there is no turbulence in the water, you can pre-tune it to the point that a mm or so of additional water will trigger it.

 

[AR1234]

Any reference or direction for a "simple float switch"?
My limited experience with floats was that they sometimes remain stuck; any insight will help.
Many thanks,
Al

 

[Danger]

Well, I'm no expert on this by any means. Something like a ping-pong ball glued to the end of a mini-lever switch (waterproofed with latex or silicon) would work quite well.

edit: The waterproofing isn't necessary if you can be sure that the switch will remain dry.

 

[Bobbywhy]

In some experimental submersible sonar units we used two metal strips glued very close together in parallel on a non-conductive surface. Each was connected by a wire to a detector circuit. To one we applied +5 Volts and the other became the input to a comparator. If water intruded (leaked in) it conducted enough of that +5 Volts to switch the comparator to "true= leak".