Application Note

Optical Dissolved Oxygen Measurement In Power Plants

Source: Hach Company

The majority of existing dissolved oxygen analyzers use amperometric sensors. While these are renowned for their accuracy and reliability, issues encountered by users include maintenance complexity and frequency, in addition to flow dependence and calibration needs.

In more complex applications, amperometric sensors suffer from interference when measuring in the presence of high levels of hydrogen—this often results in negative readings and an unreliable measurement method. Since 2006, luminescence technology has been used in power plants. This sensor showed significant reductions in maintenance complexity and frequency but was limited by its accuracy with use generally confined to oxygenated treatment (OT) environments.

In 2009, the first luminescent oxygen sensor with subā€ppb accuracy for use in power plants was launched. In this paper, we will compare and discuss the performance of both optical and amperometric oxygen sensors in both fossil and nuclear power plant applications.