These are the very cool 'brains' of the Blumat systems- simple, but oh so effective. Sometimes referred to as the 'carrots', these sensors are simply soaked in water and then inserted into the ground around the root zone of your plants. With the proper water lines connected and set up, the base of these sensors then monitor the soil moisture levels. When they determine that the soil is becoming dry, they open a valve in the top of their casing, which permits the flow of water through the drip line. The water drips into the soil until the sensor determines that there is adequate moisture in that area.
This means that the moisture levels in the soil are constantly being monitored and replenished, unlike most other irrigation systems which rely on timers to determine when and how much the plants are watered. Timer systems can be difficult to 'dial' into the ideal moisture levels. The Blumat sensors do this automatically, maintaining the moisture levels that are not only critical to the health of your plants but equally as important, the levels that are critical to the life in your soil.