PH Sensor

pH electrode (pH sensor) is an electrochemical sensor used to measure the pH value of a solution. The pH value is the logarithm of the hydrogen ion concentration in a solution, which is used to indicate the acidity or alkalinity of the solution. The range is usually between 0 and 14, with 7 being neutral, less than 7 being acidic, and greater than 7 being alkaline. pH electrodes are widely used in the fields of chemistry, environmental protection, food, pharmaceuticals, agriculture, water treatment, and experimental research, and are important tools for monitoring and regulating chemical processes.

Working principle

The working principle of the pH electrode is based on potential difference measurement, and is mainly composed of a measuring electrode (usually a glass electrode sensitive to hydrogen ions) and a reference electrode. When the two electrodes are immersed in the solution to be measured at the same time, the surface of the glass membrane reacts with the hydrogen ions in the solution to generate a potential difference related to the pH value; the reference electrode provides a stable reference potential, and the potential difference formed between the two is linearly related to the pH of the solution. The electrical signal is converted into a readable pH value by a pH meter.

Main types

pH glass electrode

pH glass electrode uses a glass membrane sensitive to hydrogen ions as a sensing element. It is sensitive to reaction and has high measurement accuracy. It is the most classic and widely used pH measurement technology, but it is sensitive to mechanical shock and needs to be carefully operated and properly stored.

General combination pH electrode

General combination pH electrode is the most common type of electrode. It integrates the measuring electrode and the reference electrode in the same housing. It has a compact structure and is easy to use. It is suitable for most aqueous solutions and conventional laboratory or industrial pH measurement scenarios.

Digital pH electrode

The digital pH electrode has a built-in chip that can convert analog signals into digital signal outputs. It has automatic identification, data storage and anti-interference capabilities. It is suitable for use in intelligent and highly automated industrial online or digital instrument systems.

High temperature pH electrode

High temperature pH electrode is designed for high temperature environments and can work stably at temperatures of 80°C or even higher. It usually has a heat-resistant glass membrane and a special sealing structure. It is widely used in chemical reactions, high temperature water treatment and steam systems.

pH electrode is an indispensable tool in modern acid-base measurement. According to different measurement environments and application requirements, various types of pH electrodes have been developed, including general composite, digital intelligent, high temperature, etc. Correctly selecting and maintaining a suitable pH electrode can not only improve measurement accuracy, but also extend the service life of the equipment and ensure the stable operation of the measurement system.