High-precision simple calibration method for soil moisture sensor

Abstract

The invention discloses a high-precision simple calibration method for a soil moisture sensor, and belongs to the technical field of measurement. The technical problem of how to provide the high-precision simple calibration method for the soil moisture sensor is solved. The method comprises the following steps: determining a standard soil moisture sensor; placing the standard sensor and the to-be-detected sensor in the same soil sample; dehumidifying when the sample soil is saturated, and automatically collecting output values of the two sensors; and performing quadratic regression fitting onthe output values of the two sensors to obtain a formula to complete calibration. According to the method, the sensor continuous change value of the water content of the sample soil from a saturated state to an air-dried state is completely recorded, the resolution reaches 1%, and the measurement precision is enhanced; meanwhile, the to-be-detected sensor only needs to be placed in the sample soilonce, multiple sample soil preparation processes are reduced, and the steps are simplified. The method is suitable for high-precision simple calibration of various types of soil moisture sensors, andhas the advantages of meeting the high-precision requirement of scientific research and meeting the efficient and simple requirement of batch production.

Description

technical field [0001] The invention belongs to the technical field of measurement, and relates to a calibration method for a moisture sensor, in particular to a high-precision and simple calibration method for a soil moisture sensor. Background technique [0002] Soil moisture sensor is more and more used in scientific research soil moisture monitoring, it has the advantages of fast, accurate, multi-point continuous measurement, etc., and can automatically and remotely measure the change of soil moisture. Domestic and foreign experimenters and engineering technicians have proposed and developed more than a dozen soil moisture sensors from different principles. So far, the soil moisture sensors commonly used in my country's water conservancy systems are mainly dielectric, including time domain reflectometry. Principle and principle of moisture sensor in frequency domain method. These two moisture sensors measure the soil water content indirectly by measuring the soil dielect...

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Problems solved by technology

[0003] Purpose of the invention: In order to solve the disadvantages of the existing soil moisture sensor calibration methods, such as the traditional soil drying method, it is necessary to repeat multiple steps of drying, grinding, sieving, sprinkling, stirring, and compacting the sample soil, the procedure is cumbersome, and the work The amount is extremely large; the weighing method has the disadvantage of manual weighing, which has a low degree of automation. Before weighing, it is necessary to disconnect the various connecting lines between the sensor and data acquisition and wipe off the attached water drops. The steps are complicated and human intervention is required. Many, big error

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