Chameleon Soil Moisture Sensor

The resistivity sensor is buried in the soil and a reader which transmits data to colour diodes is connected to the sensor. The sensor measures tension in the soil at three different depths and gives a colour-coded output i.e. blue means the soil is wet (0 to 20 kPa): do not irrigate, green means the soil is moist (20 to 50 kPa): get ready to irrigate and red means the soil is dry (greater than 50kPa): irrigate. The output can also be displayed on a card, which displays a one colour output.

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) provides technical support for users.

The longevity of gypsum based sensors is listed as a possible concern and further testing will reveal the lifespan of the sensors. Current sensors have been in the ground for over 3 years and are still performing properly ^{Interview with representative}

As part of the project funded by the Australian Centre for International Agricultural Research, the sensor was tested and found to be effective in helping farmers improve their irrigation practices.

When facilitating repairs to the sensor, basic electrical precautions should be taken.