A Composite Correction Method of Water Content Conductivity of Cultivation Substrate

Abstract

The invention discloses a compound structure sensor and a compound correction method for moisture content and electrical conductivity of a culture substrate. The compound structure sensor comprises a flat plate compound electrode, a thermal resistance temperature sensor and a signal detection circuit which are integrated on the substrate. The flat plate compound electrode comprises four pairs of electrodes on front and back surfaces; the four pairs of whole electrodes are electrical conductivity detection sensitive elements; two pairs of the electrodes in the middle are moisture content detection sensitive elements; the two types of sensitive elements work in a time-sharing mode. The compound correction method comprises the following steps: firstly, carrying out temperature compensation on the detected moisture content according to a relation between temperature and the moisture content to obtain a moisture content corrected value; carrying out the temperature compensation on a detected electrical conductivity value according to a relation between the temperature and the electrical conductivity to obtain an electrical conductivity corrected value; finally, carrying out moisture content compensation on the corrected electrical conductivity by the corrected moisture content according to a relation between the moisture content and the electrical conductivity, so as to obtain an electrical conductivity corrected value. After temperature and moisture content compensation and correction are carried out, a detection result has the advantages of high accuracy, good stability, high adaptability and the like.

Description

technical field [0001] The invention relates to a composite structure of sensitive elements for the moisture content and electrical conductivity of the cultivation substrate, and a method for compounding and correcting the detection results of the moisture content and electrical conductivity based on the electrical properties of the cultivation substrate for time-division measurement of the substrate moisture content and electrical conductivity, which belongs to detection In the technical field, it is mainly used for real-time measurement of cultivation substrate or soil water content and electrical conductivity. Background technique [0002] The water and nutrients in the cultivation medium are necessary conditions for crop growth and determine the quality of crops. As the carrier of mineral fertility, water plays the role of transporting mineral nutrients; the conductivity of the cultivation substrate reflects the total amount of soluble salts of nutrients in the substrate...

AI Technical Summary

Problems solved by technology

The four-terminal method is convenient to measure, the principle is simple, and the circuit does not need to be too complicated. It is widely used at present, but its measurement is easily affected by temperature and water content.

[0005] The sensitive elements of the sensors in the above documents all adopt probe-type structures, and the combination of the sensitive elements of water content and conductivity has not been realized. The probe-type sensitive elements have the following problems and deficiencies: There are disadvantages of poor contact; the probe and the PCB board are connected by solder joints or nuts, and there will be problems such as weak soldering, easy bending of the probe and large volume; the detection circuit of water content is complicated and the integration is low; different temperatures It has an impact on the detection of water content and conductivity, different water content has an impact on the detection of conductivity, lack of effective compensation and correction, and the detection repeatability and accuracy of the composite sensor are poor

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