Measuring Techniques for Oxidation- Reduction Potential in High Purity Water

The measurement of Oxidation-Reduction Potential (ORP) can be used in the water/steam cycle of a power plant to infer information about system reactions to water chemistry. While the measurement of ORP is by no means a new measurement, the high purity water of the water/steam cycle is a relatively new application for ORP. This presents a challenge since little information is available on proper measuring practices, such as calibration and sampling techniques. These techniques are important to properly utilize the measurement in order to obtain meaningful results. Attempts to correlate ORP findings with published data or even historical results often result in confusion and frustration. However, by applying observations from high purity water ORP installations as well as understanding the theory of the ORP measurement, measuring practices have been developed that can help to ensure reliable results for accuracy and comparison purposes.