Pichorim Sérgio Francisco, Gomes Nathan J, Batchelor John C
Graduate School of Electrical Engineering and Computer Science (CPGEI-DAELN), Federal University of Technology, Paraná (UTFPR), 80230-901 Curitiba, Brazil.
School of Engineering and Digital Arts, University of Kent, CT2 7NT Canterbury, UK.
Sensors (Basel). 2018 Feb 3;18(2):452. doi: 10.3390/s18020452.
Two solutions for UHF RFID tags for soil moisture sensing were designed and are described in this paper. In the first, two conventional tags (standard transponders) are employed: one, placed close to the soil surface, is the sensor tag, while the other, separated from the soil, is the reference for system calibration. By transmission power ramps, the tag's turn-on power levels are measured and correlated with soil condition (dry or wet). In the second solution, the SL900A chip, which supports up to two external sensors and an internal temperature sensor, is used. An interdigital capacitive sensor was connected to the transponder chip and used for soil moisture measurement. In a novel design for an UHF RFID tag the sensor is placed below the soil surface, while the transponder and antenna are above the soil to improve communication. Both solutions are evaluated practically and results show the presence of water in soil can be remotely detected allowing for their application in landslide monitoring.
本文设计并描述了两种用于土壤湿度传感的超高频射频识别（UHF RFID）标签解决方案。第一种方案采用两个传统标签（标准应答器）：一个放置在靠近土壤表面的位置，作为传感器标签，另一个与土壤分离，作为系统校准的参考。通过发射功率斜坡，测量标签的开启功率水平，并将其与土壤状况（干燥或湿润）相关联。第二种方案使用支持多达两个外部传感器和一个内部温度传感器的SL900A芯片。一个叉指电容式传感器连接到应答器芯片上，用于土壤湿度测量。在一种新颖的超高频射频识别标签设计中，传感器放置在土壤表面以下，而应答器和天线在土壤上方，以改善通信。两种解决方案都进行了实际评估，结果表明土壤中的水分可以被远程检测到，从而使其能够应用于滑坡监测。
