Temperature has an effect on the pH value.
There is a Temperature function in the Nernst equation.
This is why, for exact measurements, you must compensate for T.
This can be done with an ATC system.
Use an Automatic Temperature Compensation probe or an electrode with built in ATC system.
Basic systems have MTC, the Manual system, where you input the room temperature at the time of measurement.
The graph passes through 0.
The temperature effects are greater at the extreme ends of the pH scale.
Posted in: E-chem