ORP water testing measurements can be taken in the field to directly measure bodies of water. The pH and temperature of the water has an effect of the ORP measurement, so ORP should not be used as a direct indicator of the concentration of the oxidiser. ORP data can be collected over time to identify patterns or the normal range of ORP for this water body. By understanding the normal levels it is easier to identify when there has been an alteration that could affect the aquatic ecosystem.
ORP water testing equipment can also be used to measure the effectiveness of swimming pool sanitiser. Chlorine is an oxidiser, and helps to clean water by killing unwanted organisms through altering their chemical makeup. Continual or regular monitoring with ORP water testing equipment will ensure the correct levels of water cleanliness is maintained.
ORP monitoring is additionally used in the waste water treatment process, and can measure the performance of the treatment plant. The higher the ORP at the end of the process the cleaner the water. Monitoring the ORP at different stages of the treatment process can also help the operators to gain a more thorough understanding of the process' performance in detail.