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HOW PH CONTROL SYSTEMS WORK. Basically, a pH control system measures the pH of the solution and controls the addition of a neutralizing agent (on demand) to maintain the solution at the pH of neutrality, or within certain acceptable limits. It is, in effect, a continuous titration.
8 nov. 2019 · Learn how pH sensors and controllers are used in various industries and applications, and the challenges of pH control due to non-linearity. This article explains the basic setup of a pH control process and the factors to consider when selecting a probe and transmitter.
29 janv. 2012 · The control of pH is at best very difficult with a conventional PID control loop (Figure 1). The challenge results from variable product flow rates and the highly nonlinear pH titration curve. Figure 1. Conventional pH control – not recommended.
Many chemical and biological processes have pH control loops. Good pH control can be important for product quality as well as environmental compliance. The extraordinary rangeability and sensitivity of pH as a concentration measurement poses exceptional challenges in many aspects of pH design and implementation.
The reagent is applied to the tank at varying rates to precisely control the pH level. With the pH level at 11 detected by the sensor, the controller commands the control valve to open...
In-line digital pH controller loops will oscillate, regardless of controller modes and tuning, if setpoints are on the steep parts of the titration curves. pH electrode submersion assemblies with unencapsulated terminations below the liquid surface will eventually have wet terminations.
Here, a pH analyzer monitors the pH value of the liquid solution and a single pH controller commands two reagent valves to open when needed. If the process pH begins to increase, the controller output signal increases as well (direct action) to open up the acid valve.
