The stream system both produces and consumes oxygen. It gains oxygen from the atmosphere and from plants as a result of photosynthesis. Running water, because of its churning, dissolves more oxygen than still water, such as that in a reservoir behind a dam. Respiration by aquatic animals, decomposition, and various chemical reactions consume oxygen.
Oxygen is measured in its dissolved form as dissolved oxygen (DO). If more oxygen is consumed than is produced, dissolved oxygen levels decline and some sensitive animals may move away, weaken, or die.
DO levels fluctuate seasonally and over a 24-hour period. They vary with water temperature and altitude. Cold water holds more oxygen than warm water and water holds less oxygen at higher altitudes. Thermal discharges, such as water used to cool machinery in a manufacturing plant or a power plant, raise the temperature of water and lower its oxygen content. Aquatic animals are most vulnerable to lowered DO levels in the early morning on hot summer days when stream flows are low, water temperatures are high, and aquatic plants have not been producing oxygen since sunset.
[典 型 应 用] 广泛应用于水质处理、水文监测、废水处理、游泳池、鱼塘和化肥、化工、生物等领域的含氧量监测
[测 量 原 理] GDO-F07L5-34型氧电极是一种隔膜式极谱(clark)型传感器。由传导性电解质连接的一个阴极和一个阳极组成。 这些化学反应产生与所测量溶液中O2的分压成正比的电流。
[特 点] – 反应灵敏,稳定性好
– 无需要更换膜及电解液M/
– 适用于各种恶劣水质,膜不易损坏、抗污染
[技 术 参 数] – 测量原理:电流测量/极谱法
– 检测极限: ﹤60ppb含氧量
– 响应时间:25℃时含氧量下降90%﹤2min
- 残余电流:无氧介质中残留的室温信号﹤满度的2%
- 温度范围:测量时0~60℃
- 压力范围:0~3bar
- 电极信号:25℃时20~80nA(按客户要求定制)
- 温度补偿:热敏电阻阻值按客户要求定制
- 电极尺寸:直径33mm,长度160mm(3/4″螺纹接口),可按客户要求定制
- 电极材质:PPS
-透气膜:钢筛网增强的聚四氟乙烯及聚矽氧烷膜。