pH controllers monitor potential of hydrogen (pH) levels and initiate controller functions. They provide rapid on/off control of dosing and are used in applications such as food processing, hydroponics, water purification, and waste control. pH controllers differ in terms of control type and provide limit control, linear control, or non-linear control. Several linear control styles are available. Feed-forward or compensation devices provide direct control from a reference signal and are used in either open-loop configurations or with proportional integral derivative control (PID). Automatic reset, bias, or offset control provides proportional, integral control and is used to eliminate steady-state errors. Proportional derivative control increases the speed of response, but is noisy and may seem unstable. Proportional control produces a control signal that is proportional to the error between the reference and feedback signals. Some pH controllers include minimum and maximum limits points. Others allow adjustments to deadband or hysteresis around limit points. |
Products & Services Related to pH Controllers
Batch Controllers
Batch controllers maintain the correct size of a discrete batch of process material, such as the volume of a liquid. They are often interfaced with sensors such as load cells, or with volumetric flow meters.
Flow Controllers
Flow controllers monitor and maintain proper humidity levels in environmental test applications, or in other areas such as food storage or electronic room regulation.
Humidity Controllers
Humidity controllers monitor and maintain proper humidity levels in environmental test applications, food storage areas, and electronic equipment rooms.
Pump Controllers
Pump controllers monitor flow and/or level variables, and control a pump accordingly to maintain the desired levels. Pump control can include simply turning a pump on and off, or more advanced controls for pump speed, output pressure, etc.
Temperature Controllers
Temperature controllers accept inputs from temperature sensors or thermometers, and then output a control signal to keep the temperature at the desired level.
Web Tension Indicators
Web tension indicators measure and report tension parameters in web or other flat-sheet production processes. Some types of web tension indicators have control functionality as well.
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