A Tropf-Blumat ( "tropf" = drip) consists of a ceramic sensor and watering head [click here] fitted with a membrane. The membrane is set in motion by subpressure, it opens and thereby stops the passage of water with a squeeze valve. This subpressure, the so-called suction tension, develops in dry soil. The Tropf-Blumat works on the tensiometer principle; it uses the same process as professional tensiometers.

Water is sucked out of the ceramic sensor through the suction force of the dry earth. Suction tension develops in the Tropf-Blumat, the flexible membrane is pulled downwards, thereby allowing the passage of water, the drip tube begins dripping.

If the earth is moist enough, then the subpressure in the sensor causes the water to be sucked back into the cone, the membrane returns to its original position and squeezes the drip tube closed with a rod, the passage of water is stopped.

The point at which the valve closes is set with an adjusting knob. This determines when the drip tube is closed and by which suction tension (i.e. by which degree of dryness) the watering should begin.

Typical drip watering systems deliver water to the plants via a computer controlled time plan which does not take the actual moisture level of the soil nor the differing watering needs of individual plants into account.

The Tropf-Blumat functions differently. Neither electricity nor a computer are necessary. Tropf-Blumat works without energy input and solely on demand. Each sensor reacts to the amount of moisture surrounding it and delivers just the amount of water that is required at the time. Every Tropf-Blumat is, at the same time, a sensor and a dripper.

Because of the slow, moderately dosed supply of water being delivered, the plants always receive aged, not too cold water. In addition, the water can disperse much better in the soil. The sensor also helps save water by supplying only the amount that is needed and then stopping the delivery.

The Tropf-Blumat System functions by means of simple principles, following only the physical laws of nature. For the uninitiated, the process can be a bit difficult to comprehend. For example, the dripping, which begins as if steered by an invisible hand, may appear quite mysterious.
Whowever, those who would like to understand the Tropf-Blumat System better can silmulate the process by which it works. First, wrap a dry dish cloth tightly around the sensor, which has been adjusted and is ready for action (see Set Up, Step by Step). The cloth may have to be changed once, after 1-2 minutes the sensor will begin dripping. If the sensor is then placed in a glass of water, the dripping stops almost immediately. This kind of introduction helps the user to better understand and regulate the system.