Floor Water Sensor for Flood and Leak Detection (30 ft)

Worked well.

Just received this product. Using it to automatically add water to a pool. Connected it to an 12 bit ADC. A 10M resistor divider is required. Have ran several tests including fully submerged for hours and then fully removed from water. Works perfectly. As the device dried the voltage approaches 0V. Will put into production shortly. Update: After one season, sadly the chemistry of the pool water caused the leads to erode. As a result a different sensor maybe needed for my use. This being said the sensor did perform flawless until the erosion.

I had previously asked a question through Amazon on how far I could extend the wires on this unit. The response I got was that it had only been tested up to 30 feet. I can confirm the product works fine at least up to the 50 feet of wire I used to extend it (I wasn't able to respond to my own question). I used typical CAT5e wire that I had around, bundling 4 of the 8 strands together to create 2 heavier gauge wires. Works just fine when paired with an Arduino using a digital PULL_UP pin and the onboard ground connection.

Put a damp paper towel on it and it will alarm. Put one in pan of all hot water tanks and by you washing machine and tie into home alarm system.

Edit: this seems to retain water after the level has gone down, so it continues to report water is present. I ended up not using it. It's literally two wires leading to metal contacts, no other electronics; and hence a bit overpriced. When the contacts are immersed in water you get around 1.4Mohm of resistance from the water between them, which means they'll work with a 10 Mohm pulldown resistor and an Arduino's analog input. Water doesn't conduct enough to trigger an digital input, so if you want that you'll have to rig up your own amplifier with a 2N2222 or something. You're paying for someone to supply wire to two contacts that won't rot away in water, which is what happens if you just use bare copper wires an 1" apart for the same purpose.

I used this to build a custom "leak indicator" for an intermittent plumbing leak up in the ceiling of our garage. I built a circuit similar to the example given, and it works great! It's a well-built unit and I would definitely purchase again for all leak detection needs. Comes with pre-stripped and tinned wires which was a nice touch.

I was trying to hook it up to my home a/c system, but it is a "Normal Open" switch and I need it to be "Normal Closed"

I have worked in the security alarm industry for 2 decades. I wired this up to my Vista 20p panel, set the zone to NC (yes I know it's NO sensor, keep reading) with a 2k ohm resistor in parallel, which is the resistor this panel uses. With no water, the current goes through the resistor (instead of the NO sensor) and the panel is happy. When water is applied, the current takes the path of least resistance (the now closed 1.4k ohm sensor) and the panel doesn't see the 2k ohm resistor = alarm. I dropped the sensor in a bowl of water and it worked fine (this was wired directly to the panel with the supplied 6 foot of wire). Ran a wire to my final location in my 140 degree attic under my hvac, and the alarm went off immediately with no water present, and no metal touching the prongs. Measured the resistance of the wire+sensor at the panel and got nothing on my meter. Took the sensor off, checked the wire while opened and closed, no issues, the alarm acts as it should with no sensor on it. I don't know what is going on with this thing, but it's worthless if it only works at 6 feet from the alarm panel. Wasted money and time in my 140 degree attic.