At present,the common methods used for measuring water content are microwave method,infrared ray method and electrical capacitance method.The capacitance sensor has wide application.It is characterized by high resolution,rapid response speed and simple structure.In this paper,the size and structure of the uniplanar scattering-field capacitance sensors are optimally designed by simulation and experiment for test depth and testing feature with guard electrode for improving the anti-disturbance capability.A ne...