基于光学法的化学需氧量实时测定仪校准方法

Calibration method of chemical oxygen demand real time analyzer based on optical method

针对一种基于光学法的化学需氧量实时测定仪,提出了一种校准方法。其校准项目与技术指标包括示值误差不大于10%,重复性不大于3%,示值稳定性不超过10%。对仪器示值误差测量结果不确定度进行评定,得到相对扩展不确定Urel=2%(k=2)。采用有证标准物质或配制成系列浓度的化学需氧量标准溶液进行校准,将化学需氧量实时测定仪的探头浸入各种浓度的化学需氧量标准溶液中,即可测量并获得化学需氧量数据,完成主要性能参数的校准。

A calibration method was proposed for a real-time chemical oxygen demand analyzer based on optical method.The calibration items and technical indexes include indication error no more than 10%,repeatability no more than 3%and indication stability no more than 10%.The relative expanded uncertainty Urel=2%(k=2)was obtained by evaluating the uncertainty of measurement results of instrument indication error.The purchased certified reference materials or chemical oxygen demand standard solution with series concentrations were used for calibration.The probe of the realtime chemical oxygen demand detector was immersed in the standard solution of chemical oxygen demand of various concentrations.The chemical oxygen demand data can be measured and obtained,and the calibration of main performance parameters could be completed.