Abstract: The present invention provides a water tension sensor with a non-sintered core that allows batches of similar and standard sensors to be manufactured in a simple manner, for operation with air and with an air flow outlet, which sensor can be used to read water tension and trigger dripping. The sensor according to the invention is ideal for manually reading soil water tension and for automating irrigation systems based on a static pressure or gas propulsion mechanism.

Abstract: A pressure measuring and flow-rate controlling device includes: a flattening plate including a fluid cavity in the flattening plate; a flexible contact membrane provided on said flattening plate; a support member configured to secure the flattening plate against a sample; a pressure adjuster; an inlet tube connected to the pressure adjuster at a first end of the inlet tube, the inlet tube connected to a first end of the fluid cavity at a second end opposite to the first end of the inlet tube; and an outlet tube connected to a second end opposite of the first end of the fluid cavity, where the pressure adjuster is configured to control a flow rate of a fluid passing through the fluid cavity based on cell pressure of the sample.

Abstract: In the dihedral sensor system, two flat plates are secured to a dihedron so that the distance (L) between the edge and the meniscus and the spacing between the plates (a) on the meniscus will be a function of the dihedron tangent (?). Thus, for pure water the tension (?) is equal to the potential (T) and given by T=?2?/[L tg(?)], wherein ? is the water surface tension. In order to measure water tension in the soil, the system is coupled to porous elements, while the sensor edge is pressed directly against roots and other plant organs. Water potential, instead, is measured with the edge positioned at a few micrometers from the sample and the response takes place after the exchange of a few picoliters of water, when the condition of balance of temperature and water vapor is approached. Visually, with a sliding gauge, one measures water tensions between zero and 0.3 MPa, while with the aid of a microscope the reading extends up to 3.0 MPa. The water activity corresponding to water potentials lower than ?3.

Abstract: The present invention provides a water tension sensor with a non-sintered core that allows batches of similar and standard sensors to be manufactured in a simple manner, for operation with air and with an air flow outlet, which sensor can be used to read water tension and trigger dripping. The sensor according to the invention is ideal for manually reading soil water tension and for automating irrigation systems based on a static pressure or gas propulsion mechanism.

Abstract: The invention relates to a system for measuring cell turgor pressure (dendroturgometer), which can also operate as a firmometer. The system can also be used as an automatic dripper, wherein in this embodiment it is kept pressed by means of a flattening plate (1) against the organ (4), as well as by employing a brace (6) provided with a spring (5) that applies stable force of a magnitude higher than the product between the water pressure, regulated by a pressure adjuster (10) and the fluid layer (2) under the membrane (3), on which the plant exerts compression and obstructs the water flow. The dripping is started when the transpiration provides a drop in the cell turgor pressure of the plant, so that the resulting pressure will be lower than the adjusted water pressure. This system may also be miniaturized and used for measuring the vegetable turgor pressure by using water pressurization with an plunger (11).

Abstract: The applanation system on air permeated screen (1) of this invention is a versatile instrument for measurement of tissue firmness generated by cell turgor pressure of leaves and organs segments with thin and elastic cell wall of several stalk, leaves, fruits and roots. It is composed by an air source with adjusted maximum flow (6), a porous element (2) inserted on a screen (1), by which air flows, and a device for compression application (4). For measurements, the organ is progressively pressed against the screen until reversible interruption of the air flow crossing the porous element (2) is indicative of adequate applanation of the leaf against the screen. In this condition, one takes the firmness measurement reading as the applanation pressure (5). This firmometer enables postharvest quality evaluation and measurements for ecophysiology studies and irrigation management procedure benchmarking.

Abstract: In the dihedral sensor system, two flat plates are secured to a dihedron so that the distance (L) between the edge and the meniscus and the spacing between the plates (a) on the meniscus will be a function of the dihedron tangent (?). Thus, for pure water the tension (?) is equal to the potential (T) and given by T=?2?/[L tg(?)], wherein ? is the water surface tension. In order to measure water tension in the soil, the system is coupled to porous elements, while the sensor edge is pressed directly against roots and other plant organs. Water potential, instead, is measured with the edge positioned at a few micrometers from the sample and the response takes place after the exchange of a few picoliters of water, when the condition of balance of temperature and water vapor is approached. Visually, with a sliding gauge, one measures water tensions between zero and 0.3 MPa, while with the aid of a microscope the reading extends up to 3.0 MPa. The water activity corresponding to water potentials lower than ?3.

Abstract: The applanation system on air permeated screen (1) of this invention is a versatile instrument for measurement of tissue firmness generated by cell turgor pressure of leaves and organs segments with thin and elastic cell wall of several stalk, leaves, fruits and roots. It is composed by an air source with adjusted maximum flow (6), a porous element (2) inserted on a screen (1), by which air flows, and a device for compression application (4). For measurements, the organ is progressively pressed against the screen until reversible interruption of the air flow crossing the porous element (2) is indicative of adequate applanation of the leaf against the screen. In this condition, one takes the firmness measurement reading as the applanation pressure (5). This firmometer enables postharvest quality evaluation and measurements for ecophysiology studies and irrigation management procedure benchmarking.

Abstract: The invention relates to an irrigation control system comprising; at least one porous capsule sensor, a pressurized gas source in fluid communication with the at least one capsule sensor, and a pressure sensor configured to detect a change in gas pressure in the capsule sensor, wherein the pressure sensor is configured to control irrigation. The invention also relates to a method for monitoring soil moisture conditions comprising, providing at least one porous capsule sensor, placing the at least one porous capsule sensor in the ground, pressurizing the at least one porous capsule sensor with gas, and monitoring a gas pressure associated with the at least one porous capsule sensor. The irrigation water is controlled based on the gas pressure in the capsule sensor.

Abstract: The invention relates to an irrigation control system comprising; at least one porous capsule sensor, a pressurized gas source in fluid communication with the at least one capsule sensor, and a pressure sensor configured to detect a change in gas pressure in the capsule sensor, wherein the pressure sensor is configured to control irrigation. The invention also relates to a method for monitoring soil moisture conditions comprising, providing at least one porous capsule sensor, placing the at least one porous capsule sensor in the ground, pressurizing the at least one porous capsule sensor with gas, and monitoring a gas pressure associated with the at least one porous capsule sensor. The irrigation water is controlled based on the gas pressure in the capsule sensor.