What drawbacks are there to using industrial pH meters?
In food, chemical, pharmaceutical, sewage treatment, etc., pH measurement has been widely used. With the development of the chemical industry, especially the rapid development of the coal chemical industry, the measurement of pH value has become an important process index. In order to meet the needs of chemical production, on-line industrial pH value detection has become the main working method.
At present, most pH meters use composite glass electrodes, which have accurate measurement results and small measurement errors. However, composite glass electrodes still have high requirements on the working environment. Such as ambient temperature, process medium temperature, process pipeline pressure, process medium flow rate, etc. If the selection, installation method, etc. are not considered carefully, the following problems will appear.
(1) The pH meter installed on the process pipeline is under too much pressure, and the pH flow cell does not play a role in reducing pressure, resulting in damage to the glass tube electrode, or the electrode enters the liquid.
(2) The pH meter is installed at the site with a large temperature difference, and the protection is not in place or missing, so that the pH meter is affected by the ambient temperature and cannot be measured stably.
(3) The pH meter is installed in the process pipeline, the temperature of the medium is high, and there is not enough protection and relative temperature compensation, so the measured value of the pH meter is not stable and accurate enough.
(4) The pH meter is installed in the liquid-solid two-phase flow, causing a layer of film on the glass tube electrode to be severely washed and damaged.
(5) The pH meter is fixedly installed in the deep solution, causing the electrode cable to be immersed in the liquid for a long time, resulting in damage to the cable and serious interference to the weak millivolt signal transmitted by the electrode.
(6) When the production process is stopped, the electrode of the pH meter is exposed to the lack of liquid for a long time, causing the electrode film to dry and crack, or the material is adhered to the package, and is in contact with the air. The maintenance and protection are not timely and in place.
