Bogena Heye Reemt, Huisman Johan Alexander, Schilling Bernd, Weuthen Ansgar, Vereecken Harry
Institute of Bio- and Geosciences, Agrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Sensors (Basel). 2017 Jan 21;17(1):208. doi: 10.3390/s17010208.
Soil water content is a key variable for understanding and modelling ecohydrological processes. Low-cost electromagnetic sensors are increasingly being used to characterize the spatio-temporal dynamics of soil water content, despite the reduced accuracy of such sensors as compared to reference electromagnetic soil water content sensing methods such as time domain reflectometry. Here, we present an effective calibration method to improve the measurement accuracy of low-cost soil water content sensors taking the recently developed SMT100 sensor (Truebner GmbH, Neustadt, Germany) as an example. We calibrated the sensor output of more than 700 SMT100 sensors to permittivity using a standard procedure based on five reference media with a known apparent dielectric permittivity (1 < < 34.8). Our results showed that a sensor-specific calibration improved the accuracy of the calibration compared to single "universal" calibration. The associated additional effort in calibrating each sensor individually is relaxed by a dedicated calibration setup that enables the calibration of large numbers of sensors in limited time while minimizing errors in the calibration process.
土壤含水量是理解和模拟生态水文过程的关键变量。尽管与诸如时域反射仪等参考电磁土壤含水量传感方法相比，低成本电磁传感器的精度有所降低，但它们越来越多地被用于表征土壤含水量的时空动态。在此，我们以最近开发的SMT100传感器（德国新施塔特的Truebner GmbH公司）为例，提出一种有效的校准方法，以提高低成本土壤含水量传感器的测量精度。我们使用基于五种具有已知表观介电常数（1 << 34.8）的参考介质的标准程序，将700多个SMT100传感器的输出校准为介电常数。我们的结果表明，与单一的“通用”校准相比，针对特定传感器的校准提高了校准精度。通过专门的校准设置，放宽了单独校准每个传感器所需的额外工作量，该校准设置能够在有限时间内校准大量传感器，同时将校准过程中的误差降至最低。
