Matters needing attention when using ORP water quality analyzer
by:BOQU2023-03-20
If you have seen the sensor description of the water quality analyzer, you will know that each manufacturer has some differences, especially the internal structure of the water quality sensor. Therefore, whether it is used or calibrated in daily life, the water quality analyzers of different brands use The method is also different. For example some ORP sensor manufacturers recommend calibration in air saturated water. However, the method of creating a saturated environment is different, so it is easy to cause confusion. However, there are some similarities, for example, the analysis of the ORP sensor is related to the reference electrode. And today we will give you some 7 suggestions for using the ORP water quality analyzer. Matters needing attention when using the ORP water quality analyzer 1. ORP is a water quality parameter that has been used more in recent years, and is usually analyzed as the voltage between the platinum analysis electrode and the reference electrode. Although ORP is usually based on a standard hydrogen electrode (SHE) as a reference, practical limitations of this method lead most commercial ORP sensors to use an Ag/AgCl reference. 2. The ORP analysis result is related to the reference electrode used in the sensor. Through the known parameter relationship, the parameter results of water quality can be converted to other reference systems, such as the parameters of oxygen reduction potential, which are helpful for the analysis of dissolved oxygen and conductivity. 3. The analysis result of the ORP sensor represents the net state of all oxidation and reduction reactions in the tested sample. Positive results indicate an oxidizing environment, negative results indicate a reduced environment when referring to SHE. Together with knowledge of pH, temperature and the dominant species in the sample, ORP results help predict the oxidation states of ions in solution and whether certain reactions are likely to occur. 4. The redox potential of a solution is partly a function of temperature, which is reflected in the Nernst equation. Since all components of natural water are almost never accurately known or quantified, the relationship between ORP and temperature cannot be determined on a practical basis. However, it is recommended and encouraged to use the ORP results to record the water temperature so that analysis results can be compared. 5. The ORP electrode is easy to scale. Any substance on the electrode - organic or inorganic, visible or invisible, present or not - can cause false readings. The results of the analysis will reflect the ORP of the fouling material rather than the bulk solution. So it is very important to keep the sensor clean and smooth its surface. 6. The results of two ORP sensors analyzing the same solution will often differ. Differences usually result from different amounts and types of contamination on the electrodes and possibly changes in the potential of the reference electrode. This effect was magnified in waters with fewer species involved in redox reactions. 7. From the point of view of oxidation or reduction potential, ORP reference standards are usually very active and will dominate the analysis results of water quality. Therefore, when the analysis of natural water quality is inconsistent, it can be used as a guide to make it consistent.