| Soil moisture sensor as a major component of information technology is an importantguarantee to achieve moisture monitoring. The sensor due to frequency-domain reflectometryhave a wide range of applications with low cost, rapid measurement, ease of operation, etc.Due to the complexity of soil, to improve the frequency-domain reflectometry measurementaccuracy, my paper will add soil salinity into soil moisture sensor model, and analysis theresults of different soil be affected.The main work and conclusions are as follows:To evaluate the effect of Soil salinity and temperature on a soil moisture sensor based ondielectric properties, a loess soil from Shenmu County, Shaanxi Province, a sandy soil fromDangshan County, Anhui Province and a loess soil from Suide County, Shaanxi Province weretested. Two frequency domain reflectometry (FDR) sensors were employed to measure theoutput for different moisture contents(3.82%~22.02%), temperatures(5~50℃) and salinitylevels(0%~1%).(1) Soil salinity had a significant effect on the FDR soil moisture sensor.The indicatedmoisture output increased with soil salinity (0%~0.6%), and decreased with soil salinity(0.6%~0.7%), and was relatively stable with salinity (0.7%~1%). The maximum in0.6%.(2) The output increased with temperature obviously, the result of three kinds of soil allincreased with soil temperature at different moisture and salinity,and they are in a manner oflinear regularity basically with salinity (0%~0.4%).(3) The response surface of sensors output, moisture content, salinity, and temperaturewere given, and the mathematical model was established by Multiple regression fitting. themodel were significant by P value are less than0.0001. This model can be used to developFDR soil moisture sensor calibration equations with temperature and salinity compensationfunctions.(4) The composition of the soil affectded the sensor output signal, the calibration need tobe done before detecting different kinds of soil. |
PDF Full Text Request