DESIGN AND EXPERIMENTAL STUDY OF MOISTURE CONTENT DETECTION DEVICE BASED ON CAPACITIVE METHOD
To enable the accurate detection of grain moisture content and improve the efficiency of the drying process, a parallel-plate moisture content detection device (PPMCDD) was developed in this study. Firstly, the detection principle and influencing factors of this device are analyzed. Then the effects of three key factors as distance, thickness, relative area on the accuracy of the device were determined through simulation, and the optimal combination of parameters was obtained through analysis of variance of a regression model and response surface methodology. Finally, a simple test bench is built to verify the effectiveness of PPMCDD by comparative experiment. Through simulation and response surface analysis, the optimal combination parameters are as follows: thickness =1 mm, pacing =19.54 mm, relative area =4023.17 mm2, corresponding to the measured capacitance value of 37.676 pF. By comparative experimental analysis, it is found that the maximal relative error of the moisture content detection device evaluated in this study was 1.58%. The detection error is small, and the device exhibits high accuracy and stability and meets the design requirement.
Abstract in Chinese