Can pH meter temperature compensation eliminate all errors caused by temperature?
It must be noted that the temperature compensation set on the pH meter only compensates for the slope term of the electrode (2.303RT/F). The standard potential of glass electrodes and liquid interface potential are also affected by temperature, which are not strictly linear with temperature. At the same time, the pH electrode also requires a certain amount of time to reach equilibrium at the new temperature. Therefore, whether it is manual temperature compensation or automatic temperature compensation, it is not very sufficient. According to the Operational definition of pH measurement, in order to obtain precise measurement results, the sample solution and 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 sample solution is different from that of Standard solution.
How to determine if your pH meter is accurate?
Many users have doubts when using pH meters. Is this pH meter accurate or not? Some people judge based on work experience, some use pH test strips, and some use pH meters from the past, all of which are unreliable. In fact, the only reliable and simplest method is to use pH standard buffer solution for calibration. This is the only detection standard. Take three standard buffer solutions: pH=6.86, pH=4.00, pH=9.18 (preferably freshly prepared and at the same temperature), perform positioning calibration at pH=6.86F, slope calibration at pH=4.00, and then test pH=9.18 to see if the pH meter is accurate and qualified
