How often should the pH meter be calibrated if the reading is unstable?
The pH meter reading is inaccurate. How often should the pH meter be calibrated? The reasons for inaccurate readings can be found in two aspects: during the operation of the pH electrode and during maintenance.
Detailed analysis of pH meter electrode
1. Whether the calibration is done well before measurement; if the first calibration is not good, you can repeat the calibration. Refer to the 3-point calibration in the manual of the instrument. "How should I do the third point calibration of the pH meter?" If it really can't be calibrated, consider changing the electrode.
2. The electrode bulb is contaminated and needs to be cleaned properly: If the measured solution contains substances that can easily contaminate the sensitive bulb or block the liquid junction and passivate the electrode, the slope will decrease and the display reading will be inaccurate. If this phenomenon occurs, the electrode should be cleaned with an appropriate solution according to the nature of the pollutant to refresh the electrode. For cleaning steps, please refer to the official website above.
3. Before the electrode is immersed in each test solution, 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 test solution, resulting in inaccurate measurement and analysis.
Simplified analysis
1. The pH meter probe is dirty and needs to be cleaned.
2. The wiring is loose
3. PH meter 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, such as pure water. Of course, it may also be a problem with the instrument.
1. The pH meter has not been cleaned and there are residual reagents.
2. There is a reaction going on in the solution
3. The solution is not shaken evenly
How often should the acidometer be calibrated? Here you can tell whether you are using it in industry or a laboratory pH meter.
1. For industrial use, if the solution medium is always measured, there is no need to calibrate it. If it is removed from the original device and then put back in, it will need to be recalibrated or calibrated.
2. The laboratory uses a laboratory pH meter, which is required to be more accurate. Of course, the experiments you do are different every time, so you need to recalibrate it before each use.
