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

Worked well.

The unit is a decent water sensor for what it does, but note that there is one flaw in the design. The ABS housing is not water tight, so if/when it is fully immersed, water tends to stay in the case and continues to conduct for a variable period of time after the water level recedes. It did not matter for my application, but it may for others. I've seen similar sensor units from other manufacturers that use epoxy resin to fully protect the internals from water, but they also cost more. Also note this is not simply two contact plates in a housing with connected wire. There is a BJT transistor and a couple resistors contained in the housing, thus the minimum requirement of 5V DC supply to drive it. The transistor acts as the control element for current. At lower voltages, the sensitivity is going to be negatively impacted and may not trigger reliably if you have very clean water. Two #4 x 3/4" Phillips flat head mounting screws are provided and an instruction sheet is included in the bag that lists the specifications as well as a few sample circuit diagrams for different applications.

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.

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.

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.

This is a nice water sensor for hooking it up to a controller. I used it with an Arduino to sense a drain that backs up when my washing machine drains its water. I used a relay and was able to pause the washer until the drain water recessed. The sensor detects quickly. I agree that it would be nice if the chord was longer, but its easy enough to extend it. The app notes that come with it are nice. You will have to play with the pull down resistor value you add to work with a standard TTL input pin.

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"

Good

2 wire easy install. Tested out fine. Buy with confidence