I have a 433mhz water leak detector (one with 2 metal prongs - DY-SQ100B. I won't post a link as it may be viewed as spam...) which sits on a concrete sub-floor in a known leak area. The problem is that the concrete surface is very uneven, so when a leak occurs (tested by pouring some water along it) the sensor fails to register it.
I have potentially found a solution by placing the sensor on a cotton pad - when a leak occurs, some water is absorbed by the pad which then swells in size, and completes the circuit by being able to make contact with both probes.
Given that cotton ignites at ~200c+, is not conductive (when dry), and the sensor runs off a 3v battery, I don't see this as being a fire hazard.
That said, I have been wrong about such things in the past (fortunately not fire-related...) - can anyone see a problem with this approach?
Cheers
