In many production processes, pH control is required, and this system equipment can automatically complete the dosing and control of pH. Generally, this control system and equipment mainly consist of five major components: a pH sensor, a pH industrial online instrument, a control box, a precision dosing pump, and a dosing tank. Its working principle is as follows: First, the pH sensor detects the pH value of the liquid in the neutralization tank or chemical reaction vessel and transmits it to the pH instrument. Then, based on the requirements of the production process, high and low control points are set on the pH instrument. The pH instrument compares the input pH signal with the high and low setpoints and outputs a switch signal or proportional control signal to the control box, which then regulates the dosing pump to add acid or alkali solution. This system does not require manual operation and operates automatically, thereby greatly improving dosing accuracy and work efficiency, ensuring the stability of the production process and the safety of personnel. This system comes with a 4-20mA output and can be integrated into a PLC system for comprehensive control. It is mainly suitable for industries such as chemical, wastewater, electroplating, and fermentation.