Experiment ended when pH meter unreasonably for successive readings and neutral substances. Tested with acetic acid. The pH meters became biased very alkali. Meter failure was duplicated with a second meter which failed similarly, showing very alkali reading, 8+ within the first reading.
The probabe explanation is that I was releasing enough Hydrofluoric acid to damage the probes. The HFl likely etched the ion channels in the probe and ruined them. |