Anderson Jacob F, Huber David P, Walsh Owen A
Department of Geosciences, Boise State University, Boise, ID 83725, USA.
Earth, Environmental, and Resource Sciences, University of Texas at El Paso, El Paso, TX 79902, USA.
Sensors (Basel). 2024 Sep 18;24(18):6034. doi: 10.3390/s24186034.
Soil CO concentration and flux measurements are important in diverse fields, including geoscience, climate science, soil ecology, and agriculture. However, practitioners in these fields face difficulties with existing soil CO gas probes, which have had problems with high costs and frequent failures when deployed. Confronted with a recent research project's need for long-term in-soil CO monitoring at a large number of sites in harsh environmental conditions, we developed our own CO logging system to reduce expense and avoid the expected failures of commercial instruments. Our newly developed soil probes overcome the central challenge of soil gas probes-surviving continuous exposure to soil moisture while remaining open to soil gases-via three approaches: a 3D printed housing (economical for small-scale production) following design principles that correct the usual water permeability flaw of 3D printed materials; passive moisture protection via a hydrophobic, CO-permeable PTFE membrane; and active moisture protection via a low-power micro-dehumidifier. Our CO instrumentation performed well and yielded a high-quality dataset that includes signals related to a prescribed fire as well as seasonal and diel cycles. We expect our technology to support underground CO monitoring in fields where it is already practiced and stimulate its expansion into diverse new fields.
土壤一氧化碳（CO）浓度和通量测量在地球科学、气候科学、土壤生态学和农业等多个领域都很重要。然而，这些领域的从业者在使用现有的土壤CO气体探头时面临困难，这些探头在部署时存在成本高和频繁故障的问题。面对最近一个研究项目在恶劣环境条件下的大量地点进行长期土壤CO监测的需求，我们开发了自己的CO记录系统，以降低成本并避免商业仪器可能出现的故障。我们新开发的土壤探头通过三种方法克服了土壤气体探头的核心挑战，即在持续暴露于土壤湿度的情况下仍能对土壤气体保持开放：遵循设计原则的3D打印外壳（小规模生产经济实惠），该原则纠正了3D打印材料常见的透水性缺陷；通过疏水、CO可渗透的聚四氟乙烯（PTFE）膜进行被动防潮；以及通过低功率微型除湿器进行主动防潮。我们的CO仪器运行良好，产生了高质量的数据集，其中包括与规定火灾以及季节和昼夜循环相关的信号。我们期望我们的技术能够支持在已经开展地下CO监测的领域，并推动其扩展到各种新领域。
