Design and Fabrication of Low-Cost Sensor of Dissolved Oxygen

• Main Authors: Ya-Yuan Cheng, 鄭雅元
• Other Authors: Wen-Shang Hou
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/19297321546336235569

碩士 === 國立臺灣大學 === 生物環境系統工程學研究所 === 94 === The process of aquaculture is frequently affected by many factors, that cause oxygen deficit phenomena in the water and lead to death of fish . Since the dissolved oxygen sensor remain high in price, it would cost substantial expenditure to establish a monitoring system for cultivation .Therefore, this research utilizes low cost sensor design and assembly to develop simple and self-operated oxygen dissolving detecting system. The foundation of developing the economical sensor is adoping Galvanic cell. The voltage magnitude and the dissolved oxygen is correlated according to oxidation-reduction reaction. The dissolved oxygen sensor is composed of Ag + Zn electrode, P.E. membrane, KCl solution, plastic shell, and wires. The sensitivity and aging speed of the detecting device may be influenced by several factors, including wire length, electrolyte concentration, the capacity of electrolyte, and so on. It is concluded that the wire length below 15 meters has no influence reaction results ; the electrolyte of 1M KCL (aq) in the sensor with the volume of 17c.c. reached its full efficiency, and the voltage signal would provide stable response over four months. The total cost to fabricate a dissolved oxygen sensor is kept under NT$ 350.