PH meter temperature compensation role and PH meter electrode calibration method
The temperature compensation of PH meter should contain three parts: temperature compensation of electrode slope, temperature compensation of electrode zero point (including measuring electrode and reference electrode). The temperature compensation set on the PH meter only compensates for the slope term of the electrode (2.303RT/F). Therefore, the temperature compensation is not sufficient for pH meter measurement, nor can it completely eliminate the error caused by temperature. Just because the solution temperature term and the electrode zero temperature term, one can not be determined, the second is caused by the error is very small, it is omitted.
Second, PH electrode calibration common sense
pH electrode used for a period of time, the asymmetry potential will be a big change, so it must be calibrated regularly.
PH meter electrode calibration calibration times depend on the sample, electrode performance and the degree of measurement requirements. High-precision measurement (≤ ± 0.03pH), should be calibrated in time; general precision measurement (≤ ± 0.1pH), after a calibration can be used continuously for two weeks or even longer.
As long as the measurement shows that the pH value is accurate, there is no need to calibrate the electrode frequently. Test a standard solution that is close to the solution being measured first, and determine whether recalibration is necessary based on the magnitude of the error.
