This sensor can detect the presence of liquids. Use it to trigger an alarm or sens you an email alert (see project link) and protect you from floods. Install it outside and us it for your weather station to determine if it is raining.
See back of comparator module for pinout. Use 2 wires provided to connect sensor to comparator module. You may need more wires to connect Vcc, GND and AO or DO to your application, buzzer, microcontroller or valve control. When humidity drops, the digital output goes high.
Use it to trigger your PrivateEyePi alarm syste, or trigger an email alerts, or sound a siren when water is detected.