Sensor measuring method of water content and salt content in salty environment

It is essential to realize real-time and rapid monitoring of soil water content and salt content in the design and operation of infrastructure in soil salinized areas and laboratory model tests of water and salt migration. In this paper, a method of simultaneously monitoring water content and salt content by sensor was proposed. First, a group of calibration tests were carried out using the water content and the salt content as independent variables, and the 5TE sensor was used to study the change law of soil dielectric constant and electrical conductivity with water content and salt content. Second, nonlinear models of dielectric constant and electronical conductivity were derived based on the results of calibration test, the proposed models could well fit the calibration test data. The sensor calibration model was then obtained by solving the dielectric constant and electronical conductivity models, the coupling effect between water content and salt content was considered. Finally, a group of water-salt migration model tests of unsaturated saline soil were carried out, and the sensor calibration model was used to effectively monitor the changes in water content and salt content in the model test. The proposed coupled sensor model not only improves the measurement accuracy of any variable in water content and salt content, but also realizes simultaneously monitoring of the two variables in model tests and practical applications. © 2020, Science Press. All right reserved.