Any modern chemists around? It’s many years since i left the chemical lab. I was taught to rinse my pH electrode in demin/distilled water between measurments. Some suppliers are now telling me that you should use normal town/tap water as demin depletes the membrane.
While I see the argument, it goes against everything I’ve known. I’m also not sure that with the short rinse time it shouldn’t make any technical difference for routine measurements.
Any recommendations and even better, references would be really helpful.
When I left university, which is like 6 years ago, we used distilled water. As tap water does not usually have a pH of 7 but can vary between 6.5 and 9 (depending on location), it makes absolutely no sense for me to use it for rinsing. However this may depend on your device and application, as for household level like measuring plant water or something tap water could be sufficient.
Exactly. Thanks. This is a ‘non-domestic’ application shall we say. Measuring something with any buffer capacity at all should negate the water’s pH, so shouldn’t be a problem, but the manufacturers advice still doesn’t sit comfortably with me. But they should know!
I work for a company which designs and sells chlor-alkali electrolysers and our Technical Service Manual advises always using demin.