How often should pH meter readings be calibrated if they are unstable?
The pH meter reading is inaccurate, how often should the acidity meter be calibrated? The reason for inaccurate readings can be found from two aspects: the operation process of the pH electrode and the maintenance process. 1. Detailed analysis of the pH meter electrode 1. Whether it is calibrated well before the measurement; if the calibration is not good once, you can repeat the calibration, refer to the 3-point calibration in the instrument manual of Ziman. "How should I do the third point calibration of the pH meter?" If it is impossible to calibrate, consider changing the electrode. 2. The electrode bulb is polluted and needs to be cleaned reasonably: if the measured solution contains substances that are easy to contaminate the sensitive bulb or block the liquid junction to passivate the electrode, the slope will decrease and the displayed reading will be inaccurate. If this phenomenon occurs, it should be cleaned with an appropriate solution according to the nature of the pollutant to restore the electrode. For cleaning steps, please refer to the above official website. 3. Before immersing the electrode in each solution to be tested, it should be washed with distilled water, and the adhesive liquid should be carefully absorbed with absorbent paper to avoid contamination and dilution of the tested solution, resulting in inaccurate measurement and analysis. 2. Simplified analysis 1. The probe of the pH meter is dirty and needs to be cleaned. 2. The wiring is loose. 3. The pH meter is aging. 4. The measured liquid fluctuates greatly. The main reason is that the number of ions in the solution is too small, resulting in unstable readings. Not cleaned, there are residual reagents 2. There is a reaction in the solution. 3. The solution is not shaken. 4. How often is the acidity meter calibrated? Here to distinguish whether you are using an industrial or laboratory pH meter. 1. In industrial use, if the solution medium is being measured all the time, there is no need to calibrate it. If it is removed from the original package, it must be recalibrated or calibrated when it is put back in. 2. The laboratory uses a laboratory pH meter, which is required to be more accurate. Of course, each experiment you do is different, so you must recalibrate it before each use.
