What are the issues with using PH electrodes to monitor circulating water?
Thread Content
This post was last edited by Wandering Dawn on 2016-6-7 09:54. Dear seniors and colleagues: What problems can occur if a PH electrode is left immersed in circulating water for a long time, and can regular calibration solve these issues? How often is it appropriate to conduct a verification? What about in acidic or alkaline solutions (non-standard storage solutions: KCl, etc.)? What is the difference between preservation and online monitoring in these two aspects? Thank you!
What problems can occur if a PH electrode is left submerged in circulating water for a long time, and can regular calibration solve these issues? How often is it appropriate to conduct a verification? It is a pH electrode. It is used for online detection of the pH level of a medium, and it must be placed in a solution. I’m not sure how it’s configured in your lab – is there a flow cell set up? In general, attention should be paid to any damage to the cable at the electrode outlet. The cables of some electrodes cannot be immersed for long periods of time. Regular calibration depends on the circumstances and should be flexible. Also refer to the relevant requirements in the instrument manual. What about in acidic or alkaline solutions (non-standard storage solutions: KCl, etc.)? During normal testing, it is important to note that if the medium is dirty, the surface of the probe should be cleaned regularly to prevent deposits from forming on it. Over time, the electrodes become unusable. Be sure to check the protective fluid during regular inspections; if there is any loss, it should be examined or replenished promptly. What is the difference between preservation and online monitoring in these two aspects? The question is not clearly stated, so it cannot be answered.
PH electrodes can be immersed in any medium for an extended period of time without issues; circulating water is certainly no problem either. However, due to the poor quality of circulating water, there may be sediment or other substances that could cover the electrode, so it needs to be cleaned and inspected regularly. If it has a self-cleaning function, that would be better; I haven’t used one yet… Additionally, regular calibration is necessary.
I found on Baidu that pH electrodes should not be immersed in neutral or alkaline buffer solutions; prolonged exposure to such solutions can cause the pH glass membrane to become less responsive. Is this correct? If it’s correct, can slow response times be resolved through on-site verification? Thank you!
Thank you for the reminder. I was overthinking things and confused online monitoring with storage. The impact of online monitoring on electrodes is more complex, as it involves not only the issue of loss of protective fluid.