Development of Chemical Sensors and In-Situ Calibration: Enhanced Monitoring and Measurement of pH and Redox in Diffuse Flow Hydrothermal Systems

化学传感器和原位校准的开发：增强漫流水热系统中 pH 和氧化还原的监测和测量

• 批准号: 0927615
• 负责人: Kang Ding
• 金额: $ 48.83万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0927615&HistoricalAwards=false
• 关键词: Development; Chemical; Sensors; Situ; Calibration

This project requests support for development, calibration, and testing of pH and redox sensors that have recently been incorporated into an auto-calibration system. pH and redox can control mass transfer between geochemical and biological systems existing in areas such as diffuse flow hydrothermal habitats at mid-ocean ridges. To understand the linkages between these systems requires longer term observations, which create the requirement for in-situ calibration of pH and redox sensors. With the availability of power sources at/near deep-sea vents provided by cabled observatories, instrumentation involving in-situ measurement and calibration will be essential to transform qualitative observations to quantitative processes. The PIs propose a three year study involving both field and lab programs with the objective of improving the performance of chemical sensors in complex chemical and biological systems at low to moderate temperatures. Phase one of the study involves technical upgrades to the in-situ calibration device recently deployed at diffuse flows vent sites. Funds requested will be used to add additional pH buffer fluid reservoirs for three point pH calibration for the solid state pH electrode. Moreover, the unit that houses the pH and redox sensors will be redesigned and made smaller to decrease the internal volume and increase signal response time and sensitivity, respectively. Phase two entails reconfiguration of the stand alone calibration unit for real-time measurements, enhancing use with HOV and ROV assets. Laboratory studies are planned that involve testing of ceramic pH electrochemical sensor systems and development of a new Na-based reference electrode that may be particularly suitable for chemical, physical and temporal conditions consistent with long-term monitoring applications at diffuse flow hydrothermal vent sites.

该项目请求支持最近已纳入自动校准系统的 pH 和氧化还原传感器的开发、校准和测试。 pH 和氧化还原可以控制存在于大洋中脊扩散流热液栖息地等区域的地球化学和生物系统之间的传质。要了解这些系统之间的联系需要长期观察，这就需要对 pH 和氧化还原传感器进行现场校准。随着电缆观测站在深海喷口/附近提供电源，涉及现场测量和校准的仪器对于将定性观测转化为定量过程至关重要。 PI 提出了一项为期三年的研究，涉及现场和实验室项目，目的是提高复杂化学和生物系统中化学传感器在中低温度下的性能。该研究的第一阶段涉及对最近部署在扩散流排放点的现场校准装置进行技术升级。请求的资金将用于添加额外的 pH 缓冲液储液罐，用于固态 pH 电极的三点 pH 校准。此外，容纳 pH 和氧化还原传感器的单元将被重新设计并变得更小，以分别减少内部体积并增加信号响应时间和灵敏度。第二阶段需要重新配置独立校准单元以进行实时测量，从而增强 HOV 和 ROV 资产的使用。计划进行实验室研究，包括测试陶瓷 pH 电化学传感器系统以及开发一种新型钠基参比电极，该电极可能特别适合与扩散流热液喷口处的长期监测应用相一致的化学、物理和时间条件。