溶氧传感器的温度特性研究及其补偿

Temperature Dependence and Compensation for the Dissolved Oxygen Probe

分析了溶液中氧的溶解特性,对可高温灭菌的极谱型溶氧电极的工作原理进行了阐述,分析了溶氧传感器的温度特性。采用溶氧电极温度特性公式近似温度所引起的全部测量误差,试验结果验证了该方法的可行性。根据以上的分析,得出了温度补偿策略,试验数据进一步表明温度变化对溶氧测量有着重要的影响,文中提出的温度补偿策略简便有效,可以取得与国外先进仪表相似的性能,极大地降低控制系统成本。

Some transfer characteristics of oxygen from gas to liquid are presented. For the bioreactor, the Dissolved Oxygen （DO） sensor is the sterilizable polargraphic electrode with gas-permeable membrane. The operation principle of DO probe is shown, and its temperature dependence is analyzed. A simple method is proposed to describe the total DO measurement error resulted from the temperature, and the experimental data illustrate that this approximation scheme is effective. According to the DO definition, a com- pensation scheme is designed using the approximation formula. The experimental results show that the reactor temperature is an important factor for the measurement of Dissolved Oxygen. Moreover, the proposed method may achieve similar performance compared with the METTLER-TOLEDO transmitter so that it may reduce the hardware price of the control system dramatically.