About temperature compensation of pH

I often receive many inquiries from users. In order to let all the friends who have the same questions know the answers, the partners of Corsus have selected some common questions to answer. Our topic is about temperature compensation of pH, hope to bring you some help! Customer: The buffer I bought is 7.00, why does it show 7.02 after calibration? And why is the value I tested in winter different from the value tested in summer? Colleagues: That’s because the pH test is the value of the current temperature, and the displayed value is naturally different at different temperatures! Customer: Doesn’t the pH meter have a temperature compensation function? Colleagues from Cors: Our pH meter has a temperature compensation function, but it does not compensate the pH value at different temperatures to 25°C for display! What does the temperature compensation function of pH refer to? Below, the friends of Rongkuosi will tell you one by one. What does the temperature compensation function of pH refer to? The temperature compensation of pH does not mean that the pH value of the sample is compensated to 25°C during the test. Usually what we call pH temperature compensation mainly refers to the temperature compensation of the electrode. As we all know, the measurement principle of pH is the Nernst equation, which refers to the relationship between the measured potential difference mV and pH. The Nernst equation E=E0-pH*2.3RT/F (where E: measured potential, E0, R and F are both constants), and only the temperature is unknown in the slope of the equation 2.3RT/F. When the temperature is different, the slope of pH is different, so the temperature compensation of pH usually refers to compensating the slope of the electrode, automatically compensating the slope of the electrode to the slope at the current test temperature, and obtaining the pH value at the current test temperature.