Applications of Soil Moisture Sensor with Electrokinetic Ion Trap Mechanism

in Sciences Citation Index(SCI), 科學引文索引資料庫(SCI)
標題Applications of Soil Moisture Sensor with Electrokinetic Ion Trap Mechanism
出版類型SCI(Sciences Citation Index)
AuthorsMing-Hsi Lee, 李明熹, & Chia-Yen Lee 李佳言
出版日期2014 / 9

A sensor comprising a pair of stainless steel planar electrodes and a capacitance meter is proposed for the real-time monitoring of
the moisture content in soil. As rain falls on the ground, the moisture content of the soil between the two electrodes increases.The
resulting change in the dielectric constant of the sensingmaterial (soil) produces a corresponding change in the capacitance signal,
fromwhich the moisture content can then be inversely derived.Themeasurement performance of the proposed sensor is enhanced
by means of an ion trap mechanism comprising two graphite mesh electrodes positioned orthogonally to the measurement
electrodes. A DC voltage is applied to the two electrodes such that the anions and cations in the water are trapped by the positive
and negative electrodes, respectively, thereby minimizing their effects on the sensing operation. The experimental results show
that the proposed sensor achieves a high degree of sensitivity (i.e., 1.27 ??F/%) for gravimetric water contents ranging from 21 to
28%. Moreover, it is shown that the sensor has a repeatability of ±0.71% and ±0.55% for low and high gravimetric water contents,

期刊名稱International Journal of Distributed Sensor Networks
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