Department of Water Resources Development and Management, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India.
Department of Electronics and Communication, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India.
Environ Monit Assess. 2024 Aug 7;196(9):793. doi: 10.1007/s10661-024-12946-y.
This study aims to assess the effectiveness of PCB-based capacitive soil moisture sensors for local field conditions. The electrical scheme of designed sensors has been presented in this study. The PCB-based capacitive soil moisture sensors are calibrated using a linear equation developed between analog values of capacitive sensors and soil moisture content measured from the gravimetric method. The performance of the designed soil moisture sensors was assessed at five different locations at varying depths (i.e., 15 cm, 30 cm, and 45 cm). The calibration results indicated a positive correlation between the soil moisture content and measurement frequency of the sensor for wheat crop, with R values of 0.72, 0.83, and 0.83 for 15 cm, 30 cm, and 45 cm depths, respectively. Results reveal that 85% of the sensors accurately detected the patterns in soil moisture fluctuations during the cropping period. The designed capacitive sensors demonstrated a maximum relative error of 5.87% for 45 cm depth. However, the relative error remained below 5% for the 15 cm and 30 cm soil depths. For the sugarcane crop, R values vary from 0.66 to 0.82, with the highest relative error of 5.22% at a 15 cm depth. These sensors offer a highly cost-effective solution for farmers, with the entire wireless sensor network system including one sensor node, three soil moisture sensors, and one soil temperature sensor, which is priced at approximately $150, making it a practical and affordable option for widespread adoption.
本研究旨在评估基于 PCB 的电容式土壤湿度传感器在当地现场条件下的有效性。本研究提出了设计传感器的电气方案。通过在模拟值和重量法测量的土壤湿度值之间建立线性方程，对 PCB 电容式土壤湿度传感器进行校准。在五个不同深度（15cm、30cm 和 45cm）的五个不同位置评估了设计的土壤湿度传感器的性能。校准结果表明，传感器的土壤湿度含量与测量频率之间呈正相关，对于冬小麦，相关系数 R 值分别为 0.72、0.83 和 0.83；对于 15cm、30cm 和 45cm 深度。结果表明，85%的传感器能够准确检测到种植期土壤水分波动的模式。设计的电容式传感器在 45cm 深度的最大相对误差为 5.87%。然而，在 15cm 和 30cm 土壤深度，相对误差仍保持在 5%以下。对于甘蔗作物，R 值从 0.66 到 0.82 不等，在 15cm 深度的相对误差最高为 5.22%。这些传感器为农民提供了一种极具成本效益的解决方案，整个无线传感器网络系统包括一个传感器节点、三个土壤湿度传感器和一个土壤温度传感器，价格约为 150 美元，是广泛采用的实用且经济实惠的选择。
