洪水および漏水の検出用フロアウォーターセンサー

Worked well.

Good

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

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.