Characteristics of PH Meter Buffer and Introduction of PH Digital Sensor
Buffer for pH meter
1. What is the standard buffer solution of pH meter? What are the characteristics?
A pH buffer solution is a solution that keeps the pH value stable. If a small amount of acid or base is added to this solution, or a small amount of acid or base is produced by the chemical reaction in the solution, and the solution is properly diluted, the pH value of the solution is basically stable. Or alkali or dilution, and the solution that makes the pH value not easy to change is called pH buffer solution.
pH meter standard buffer solution has the following characteristics:
(1) The pH value of the standard solution is known and reaches the specified accuracy;
(2) The pH value of the standard solution has good reproducibility and stability, and has a large buffer capacity, small dilution value and small temperature coefficient;
(3) The preparation method of the solution is simple;
2. For the pH meter, what is the main function of the pH buffer solution?
(1) Calibration and calibration of the pH meter before pH measurement
(2) It is used to verify the accuracy of the pH meter, for example, after calibrating the pH meter with pH6.86 and pH4.00, insert the pH electrode into the pH9.18 solution, and check whether the displayed value of the instrument is consistent with the pHs value of the standard solution;
(3) Check whether the pH meter needs to be re-calibrated when measuring the general accuracy. After the pH meter is calibrated and used, it may drift or change. Therefore, before the test, insert the electrode into the standard buffer solution that is close to the solution to be tested, and determine whether it needs to be re-calibrated according to the size of the error.
⑷Check the performance of pH electrode
How to prepare pH standard buffer solution?
For general pH measurement, a complete set of pH buffer reagents (250ml can be prepared) can be used. When preparing the solution, deionized water should be used and boiled for 15-30 minutes in advance to remove dissolved carbon dioxide. Cut the plastic bag and pour the reagent into a beaker, dissolve it with an appropriate amount of deionized water, rinse the packaging bag, then pour it into a 250ml volumetric flask, dilute to the mark, and shake well.
