The Opus XT300 Sensor is being used together with the wireless soil moisture monitor
The base monitor can handle up to 3 sensors. In a free field without major obstacles the range of the wireless signal is about 100 meter. The radio frequency the monitor uses is 433,92MHz. We recommend to put the wireless soil moisture sensor in the shade to prevent a wrong temperature reading as a result of the heating of the sun.
How does the XT300 wireless moisture sensor work?
The XT300 sensor uses capacitance domain technology to measure the moisture level in the soil (= dielectric measuring). The sensor transmits these data to the monitor (the base station). The LCD screen shows you the soil moisture reading.
You will find more information for the Wireless Moisture Monitor here.