ph measurement

[hamidpia]

It is understood that when measuring pH using a pH electrode the temperature error from the electrode varies based on the Nernst Equation as 0.03pH/10C/unit of pH away from pH7. Now if Ph meter has Automatic Temperature compensation feature installed then shall it read same Ph at all temperaures for the same solution, whereas I have seen it does not, Ph does vary with temperature I am told that ATC takes care upto 0.03Ph/10C/unit of pH away from pH7, above that it is depicted as changed Ph. Thanks

[hermanntrude]

pH meters are famous for being unreliable. They tend to get easily put out of calbration and are way too sensitive to things like temperature, movement, proximity of the glass of the beaker in which the reading is being taken.

 

personally i'd reccomend either using pH paper or a very expensive pH meter.

[John Cuthber]

The real pH of a solution can change with tremperature. For example the pH of pure water varies from about 7.5 near freezing to about 6.5 when it's near boiling.

There's also a change in the electrode's response. You can correct for that (to some degree) but you will lose accuracy.

 

Why do you want to know?