Why do industrial pH meters, industrial acidity meters, and laboratory pH meters need to be recalibrated?
We often use pH and acidity meters to measure the pH value of solutions. After frequent use, we need to recalibrate the pH and acidity meters from time to time to ensure measurement accuracy. Do you know why pH and acidity meters need to be recalibrated? The number of calibration cycles depends on the performance of the sample, pH meter electrode, and the degree requirements for measurement. High precision measurement (≤ ± O.03 pH) should be calibrated in a timely manner. General precision measurement (≤ ± 0. lpH), can be used continuously for one week or longer after one calibration. In addition, a standard buffer solution that is close to the measured solution can be tested first to determine whether recalibration is necessary based on the size of the error. In the following situations, the instrument must be recalibrated:
(a) Electrodes that have not been used for a long time and newly replaced electrodes.
(b) After measuring the concentration of acid (pH<2), or after measuring the concentration of alkali (pH>12).
(c) After measuring solutions containing fluoride and more concentrated organic solutions.
(d) When the temperature of the measured solution differs significantly from the calibration temperature.
What measures should be taken for unstable pH meters?
What measures should be taken if the pH meter is unstable? Answer: Find the reason for the instability of the pH meter Do you use a pH meter with a glass electrode to measure instability, or do you find that the MV value is unstable when checking the pH timer? If the pH meter with a glass electrode is unstable during measurement, it is likely caused by the glass electrode. You can perform a pH meter calibration. If the calibration is normal, replace the glass electrode (or activate the glass electrode). If the pH meter is unstable and the MV value jumps randomly, it is likely due to moisture or circuit problems. If it gets damp, it should be dry. Circuit problems can only be sent for repair.
