Revive/rejuvanate dry pH probes?

[GalaxyBenny]

The title more or less says it all. I picked up some used equipment and the pH probes were not stored wet. Some of them look new, but they don't appear to calibrate correctly. I did some research online and it claims you can sometimes rejuvenate a probe with alternative soaking in low pH (0.1-1M HCl)/high pH solutions (NaOH). If this works would CaOH work equally as well (also high pH and I have that on hand). Others also specifically mention soaking in potassium chloride (the typical storage solution?). I even saw one that recommended soaking in boiling nitric acid (in a fume hood of course) followed by soaking in hot filling solution.

It's likely all this isn't worth it, just buy some new probes. But before I throw away 3-4 otherwise perfectly good looking pH probes, I thought I would check with the experts.

@Randy Holmes-Farley - Any advice? Is it worth trying to fix them or just replace and stop worrying about it? Are there "quick" things you would try, and if those fail then toss them?

Thanks in advance for your advice.

 

[Dan_P]

The title more or less says it all. I picked up some used equipment and the pH probes were not stored wet. Some of them look new, but they don't appear to calibrate correctly. I did some research online and it claims you can sometimes rejuvenate a probe with alternative soaking in low pH (0.1-1M HCl)/high pH solutions (NaOH). If this works would CaOH work equally as well (also high pH and I have that on hand). Others also specifically mention soaking in potassium chloride (the typical storage solution?). I even saw one that recommended soaking in boiling nitric acid (in a fume hood of course) followed by soaking in hot filling solution.

It's likely all this isn't worth it, just buy some new probes. But before I throw away 3-4 otherwise perfectly good looking pH probes, I thought I would check with the experts.

@Randy Holmes-Farley - Any advice? Is it worth trying to fix them or just replace and stop worrying about it? Are there "quick" things you would try, and if those fail then toss them?

Thanks in advance for your advice.

Unless the effort makes you feel good, toss the probes and move on to more exciting activities.