Clement Rémi, Fargier Yannick, Dubois Vivien, Gance Julien, Gros Emile, Forquet Nicolas
INRAE, REVERSAAL, F-69626 Villeurbanne Cedex, France.
GERS-RRO, Univ Gustave Eiffel, IFSTTAR, Univ Lyon, F-69675 Lyon, France.
HardwareX. 2020 Jul 2;8:e00122. doi: 10.1016/j.ohx.2020.e00122. eCollection 2020 Oct.
The use of electrical resistivity tomography in laboratory or field experiments for environmental purposes has been increasing in recent years. The development of commercial devices has thus far focused on the quality of measurements and their robustness in all field cases. However, both their costs and lack of flexibility to adapt to specific applications have limited their prevalence in the environmental sector. This article presents the development of a low-cost, open hardware resistivity meter to provide the scientific community with a robust and flexible tool for small-scale experiments. Called OhmPi, this basic resistivity meter features current injection and measurement functions associated with a multiplexer that allows performing automatic measurements with up to 32 electrodes (at a cost of less than $500). The device was first tested using a soil-analog electrical circuit to verify the reliability and robustness of the measurements. Results show that OhmPi offers a wide range of resistance measurements, from 0.2 to 1000 O, for contact resistances between 100 and 5000 O. Measurements were then carried out on a small field experiment, in demonstrating good stability of the OhmPi measurements, as well as a strong correlation with the output of a commercial reference instrument.
近年来，为环境目的而在实验室或现场实验中使用电阻层析成像技术的情况日益增多。到目前为止，商业设备的开发主要集中在测量质量及其在所有现场情况下的稳健性上。然而，它们的成本以及缺乏适应特定应用的灵活性，限制了它们在环境领域的普及。本文介绍了一种低成本、开放式硬件电阻计的开发，旨在为科学界提供一种用于小规模实验的稳健且灵活的工具。这种基本电阻计名为OhmPi，其特点是具有电流注入和测量功能，并与一个多路复用器相关联，该多路复用器允许使用多达32个电极进行自动测量（成本低于500美元）。该设备首先使用土壤模拟电路进行测试，以验证测量的可靠性和稳健性。结果表明，OhmPi对于100至5000Ω的接触电阻，能提供0.2至1000Ω的广泛电阻测量范围。然后在一个小型现场实验中进行了测量，结果表明OhmPi测量具有良好的稳定性，并且与商业参考仪器的输出具有很强的相关性。
