Does temperature compensation remove all temperature-induced errors?
It must be pointed out that the temperature compensation set on the pH meter is only the slope item of the compensation electrode (2.303RT/F). Also affected by the temperature are the standard potential of the glass electrode, the liquid junction potential, etc., which are not strictly linear with the temperature. At the same time, it takes a certain amount of time for the pH electrode to reach equilibrium at the new temperature. Therefore, neither manual temperature compensation nor automatic temperature compensation is sufficient. According to the operational definition of pH measurement, in order to obtain precise measurement results, the sample solution and the standard solution should be measured at the same and constant temperature, which is the principle of isothermal measurement. For pH measurement with general accuracy requirements, temperature compensation can be used when the temperature of the sample solution is different from that of the standard solution.
