Effect of liquid flow rate on ph meter measurement
The liquid flow rate has an influence on the pH meter measurement. In most applications (not high-purity water), the liquid flow rate has little effect on the pH meter measurement. When the sample passes through the pH electrode at a flow rate of 0-2m/sec, it will have a small impact on the diaphragm of the pH reference electrode, and the measured value of the pH meter will have a deviation of ± 0.1.
The liquid pressure will also have a certain influence on the measurement of the pH meter, because it directly acts on the diaphragm of the reference, which will press the process medium into the diaphragm. At very low or high pH (<4 or >10 pH), the effect will be greater, with a ± 0.2 pH deviation, depending on the actual application.
The continuous high pressure and high flow rate will cause the compression and expansion of the electrolyte, which will promote the diffusion of the electrolyte or pollute the diaphragm, thereby shortening the life of the electrode of the pH meter.
It is best to install the pH electrode in the normal flow and pressure bypass to achieve the highest measurement performance and longest life.
How long should the pH meter electrode be calibrated
The calibration time of the online pH meter electrode depends on the respective processes on site. The more stable the on-site process conditions (temperature, pressure, composition, no dirt, etc.), the more stable the online pH meter measurement and the longer the calibration interval.
Generally speaking, most online pH meter electrodes are calibrated once a month or once a month, and a longer or shorter calibration interval is also possible according to the actual situation on site. Under the premise of ensuring the accuracy of pH calibration, it is best to calibrate more frequently at the beginning, and then gradually extend the calibration interval.
