Kemo m173 soil moisture humidity sensor module kemo m173 p this watering regulator module measures the soil moisture and depending on the result can be used to turn your watering system on and off the measuring probe of the module is buried in the ground at the desired depth and is connected to the main module with approx 2m of cable the sensor cable can be extended with normal 2 way cable up to 20m if your garden is to be watered only on certain days or at particular times of the da