overview

Everyone knows that the choice of water quality sensors is very important. In water measurement, the ph sensor is one of the important tools. However, there are many kinds of ph sensors on the market, which makes many consumers wonder “how do I choose the right ph sensor?”, “Where do I start?”. This requires us to know the ph sensor information before using or buying, and then choose the appropriate sensor. In this article, we provide you with the types and applications of pH sensors suitable for different places.

Different types of pH sensor

According to different usage environments, there are many kinds of ph sensors on the market. The correct choice of ph sensors can make your project more effective. On the contrary, choosing the wrong pH sensor will not only lead to inaccurate measurement, but also damage the electrode, leading to an increase in project cost. Different application places, we introduce to you the following 6 most widely used ph sensor electrodes.

1. pH composite sensor

An electrode that combines a pH glass electrode and a reference electrode is called a pH composite sensor. If the outer shell is plastic, it is called a plastic-shell pH composite sensor. If the outer shell is glass, it is called a glass pH composite sensor. The biggest advantage of the composite sensor is that it combines two into one and is easy to use.

2. Desulfurization pH sensor

Desulfurization pH sensor is used for pH measurement in flue gas desulfurization. The electrode adopts a gel electrode, which is maintenance-free. The electrode can maintain high precision even at high temperature or high pH values. This kind of slurry and desulfurization special PH electrode, because it is flat, it is not easy to scale and easy to clean. Therefore, it is the most suitable electrode for desulfurization. It adopts anti-fouling annular PTFE liquid junction, which is not easy to be blocked and can be tested online for a long time.

3. PTFE pH sensor

The PTFE PH sensor is made of polytetrafluoroethylene, which is resistant to strong acids and alkalis, and is resistant to corrosion. It is suitable for monitoring the pH value in occasions containing organic substances. It uses a low-impedance glass sensitive film, which is wear-resistant, resistant to strong acids and alkalis. The probe is front-facing The ring-mounted protection ring protects the glass bulb with better accuracy and linearity.

4. Electroplating pH sensor

The double liquid junction is adopted to reduce the pollution of the reference liquid. The long-distance reference diffusion path greatly prolongs the service life of the electrode in harsh environments and is convenient for maintenance.

5. pH Glass sensor

The pH value of the solution measured by the pH glass electrode is the saturated calomel electrode as the reference electrode, the glass electrode as the indicator electrode, and the measured water sample to form a working battery, and then use a PH meter to measure the working electromotive force, and the PH meter directly reads the pH. value. The pH glass electrode measures PH accurately and quickly, and is less interfered by factors such as water chromaticity, turbidity, colloidal substances, oxidants, reducing agents and salinity.

Note: 1. The accuracy of the measurement result is first determined by the accuracy of the pH standard value of the standard buffer solution.
2. The glass electrode and gangong electrode should be selected, processed and installed according to the specifications.
3. The pH value of the water sample should be measured on site, otherwise, the sample should be kept at 0-4℃ after sampling, and the measurement should be carried out within 6 hours after sampling. Pure water is neutral, and its pH value is 7.0 at 25 degrees. The solution below this value is acidic, and the value above this value is alkaline. Pure water also ionizes (a decomposition process that decomposes charged ions) to produce hydrogen ions.

6. PH antimony sensor

The PH antimony electrode is a redox electrode. When the surface of the metal antimony is in contact with the test solution, the surface is oxidized to form Sb2O3. The potential difference between the metal antimony and the oxide depends on the concentration of Sb2O3, and the concentration of Sb2O3 is consistent with that in the solution. The hydrogen ion concentration is related to, therefore, the pH value of the solution can be measured by measuring the potential difference between antimony and antimony trioxide. Antimony electrode is a pH-sensitive electrode. Because it is relatively strong, it is most suitable for the occasions where the electrode is required to be strong, but it has great limitations. Any component that has a substitution effect with antimony or generates complexes and ions cannot be used directly. . Antimony electrode is suitable for PH test of solution containing hydrofluoric acid.

Note: 1. The accuracy of the measurement result is first determined by the accuracy of the pH standard value of the standard buffer solution.
2. The glass electrode and gangong electrode should be selected, processed and installed according to the specifications.
3. The pH value of the water sample should be measured on site, otherwise, the sample should be kept at 0-4℃ after sampling, and the measurement should be carried out within 6 hours after sampling. Pure water is neutral, and its pH value is 7.0 at 25 degrees. The solution below this value is acidic, and the value above this value is alkaline. Pure water also ionizes (a decomposition process that decomposes charged ions) to produce hydrogen ions.

6. PH antimony sensor

The PH antimony electrode is a redox electrode. When the surface of the metal antimony is in contact with the test solution, the surface is oxidized to form Sb2O3. The potential difference between the metal antimony and the oxide depends on the concentration of Sb2O3, and the concentration of Sb2O3 is consistent with that in the solution. The hydrogen ion concentration is related to, therefore, the pH value of the solution can be measured by measuring the potential difference between antimony and antimony trioxide. Antimony electrode is a pH-sensitive electrode. Because it is relatively strong, it is most suitable for the occasions where the electrode is required to be strong, but it has great limitations.

Any component that has a substitution effect with antimony or generates complexes and ions cannot be used directly. . Antimony electrode is suitable for PH test of solution containing hydrofluoric acid.More water quality monitoring equipment welcome to JXCT.