FI90919C - Method and apparatus for measuring the amount of water contained in a material - Google Patents

Description

i 90919

METHOD AND APPARATUS FOR MEASURING THE WATER VOLUME IN THE MATERIAL

The invention relates to a method and an apparatus for measuring the amount of water contained in a material.

The water volume measuring devices currently in use are either continuous or periodically sampled. Continuous devices are usually based on force measurement, infrared measurement, optical measurement, microwave measurement or radioactive measurement.

However, current measuring devices are not able to measure water levels from materials with a high dry matter content or do not measure large amounts of material as a whole, but generally measure the meter from indiscriminate proximity or take a sample of the material, possibly withheld from water. distributed in the material. Similarly, the meters measure the color as the water phase changes. Meters have not been developed to measure multiple water phases and simultaneously. Generally, meters also incorrectly measure temperature, dry matter color, or optical properties.

The method and device according to the invention provide a decisive improvement in the above-mentioned drawbacks. To achieve this, the method and the device according to the invention are characterized by what is set forth in the characterizing parts of claims 1 and 3.

The most important advantages of the invention are its ability to continuously measure water content even from materials with large amounts of solids. In addition, the method and the device can measure the amount of water in any phase and thus the temperature can vary on a large scale. In addition, it measures the amount of water from the desired amount of material, not only from the immediate proximity of the meter or from a particular sampling point. It also does not depend on the optical properties of the material.

In one embodiment of the method (Figure 1), the material flows in a metal cylinder which forms one (outer) electrode 1). A second (inner) electrode 2) is placed in the middle of this lesion. A standard electric field is routed between them. The density of the electric flux depends on the permeability of the dry matter and water of the material. In general, the permeability of the solid due to the polarization of the material is very much lower than the permeability of water and very close to the permeability of air. Thus, by measuring the current flowing through the material, a result proportional to the number of water molecules is obtained.

The transmitter of the electronics unit connected to the central electrode of the device according to Fig. 1 3) transmits a constant voltage and a constant frequency signal to the material. The greater the permeability of a substance, the greater the current through the material. The current signal is measured and converted in a measuring transformer 4) to a direct current that is proportional to the amount of water and can be read from the display device.

Depending on the geographical location of the measurement site, the permeability of the water may vary according to the seasons. The method according to the invention includes a compensation measurement at the second electrode 11a, which measures only the permittivity of the water present.

II

90919 3 and the electronics unit compensates for possible variations.

In another embodiment of the method (Figure 2), the material is located between two electrodes, from which the measurement is performed by the same method

Claims (4)

4 A method for measuring the amount of water contained in a mixture of solid and water, comprising passing a high frequency electric current of 1 to 100 MHz through the material and measuring the amount of current passing through the mixture and the flow dependent on the permeability of the mixture. through a metal tube (1) acting as one electrode, wherein the second electrode (2) is placed in the middle of the tube, that a high-frequency electric field is formed in the material to be measured by switching between the electrodes (1, 2) at a voltage and frequency constant; the amount of water and the mixture of solids flowing through the tube (1) can be measured continuously on the basis of the current flowing between the electrodes (1, 2). Method according to Claim 1, characterized in that the permeability of the water in the mixture is measured separately without solids by passing an electric current obtained by means of a constant AC voltage through the water and a constant amount of water obtained by measuring the mixture of water flowing through the pipe. on the basis of the value of the permittivity to correspond to the actual value of the water volume. An apparatus for measuring the amount of water contained in a mixture of water and solids, the apparatus comprising electrodes (1, 2) and a measuring transmitter (3) connected thereto for generating a high-frequency electric current, and a measuring device (4) for measuring current through a mixture of water and solids. the first outer electrode formed by the housing (1) of the metal tube 90919 5 and the inner electrode (2) in the middle thereof, that the measuring transmitter (3) supplies a constant alternating voltage of frequency and voltage between the electrodes (1, 2), thereby continuously measuring the water content of the mixture is passed as a continuous flow through the tube (1) forming the outer electrode and the amount of water is continuously measured from the flow. Device according to Claim 3, characterized in that it comprises a measuring transformer (4) for measuring the electric current, which converts the high-voltage alternating current into a direct current proportional to the permittivity of the mixture and thus to the amount of water therein. 6