Blumat Drip

The suction power of dry soil draws some water from the ceramic sensor. In the Drip-Blumat, this creates suction tension, which pulls the flexible membrane down and opens the water passage, causing the drip hose to start dripping. When the soil is sufficiently moist, the negative pressure in the sensor draws the water back, the membrane returns to its original position, and a pin pinches the drip hose, closing the water passage. The rotary knob is used to adjust the closing position of the valve. This determines when the drip hose is closed and at what suction tension, or dryness, the watering begins.