An <i>In Situ</i> Dissolved Oxygen Monitoring System Based on Fluorescence Quenching Phase Detection

Abstract

As a major indicator in marine life research and geochemistry, the in-situ monitoring of dissolved oxygen has become increasingly important in the assessment of marine ecosystem. It has been proved that fluorescence quenching may result in shorter fluorescence lifetime. Based on it, this paper proposes an in-situ dissolved oxygen monitoring system of high precision and low power consumption applicable to long-term monitoring of complex marine environment. Using phase detecting method, an AC analog amplification channel on Precision photoelectric detection, and used digital phase detection method and three order integral average method to detect the phase offset. The ultralow-power microcontroller was used to control system. The experiments results show that the system has high stability, high precision(0.02mg/L), quick response time(≤40s), low power consumption(peak current ≤10mA), strong anti interference ability.

Review of Dissolved Oxygen Detection Technology: From Laboratory Analysis to Online Intelligent Detection

“…The sensor had a fast response and was suitable for real-time on-site monitoring. Zhang recommended a phase detection method for the AC analog amplification channel in precision photoelectric detection and adopted the digital phase detection method and the three-order integral average method to detect the phase offset [175]. The experimental results showed that the system has good stability, a high detection accuracy, and a quick response (within 40 s), and it can resist all types of interference.…”