一种土壤盐分传感器的敏感场分析及其校正研究

从基本理论出发,计算了一种新型探针式四电极外部电势的理论分布,通过对敏感场分析得出了该四电极的敏感响应范围为径向直径约1.5倍电流电极间距的椭球体.通过研究土壤表观电导率(ECa)、土壤盐分(EC1:5)和土壤质量含水率(θ)之间的关系,利用非线性回归的方法获得了精度较高的ECa-EC1:5校正模型,为土壤盐渍化调查和监测提供了便捷有效且费用低廉的方法.

Sensitivity distributions and calibration of a sensor of soil slinity

The mathematical model for a ring-shape four-electrode probe was established and the sensitivity distributions of the electrical potential and the current density in radial and axial directions were calculated by using numerical method under the additional assumptions that the sensor was surrounded with a homogenous medium.By studying the sensitivity field,the measuring range of this sensor was estimated to be an ellipsoids whose radial diameter was about 1.5 times of the spacing between the two current electrodes.Moreover,for the purpose of measuring soil salinity,we studied the relationship between soil apparent conductivity ECa,soil water content θ and soil salinity EC1:5 and fitted an accurate empirical model for converting the ECa detected by the probe to customary EC1:5.This four-electrode probe would provide a simple,quick and inexpensive method to measure and survey soil salinity.