Adequate water quality is essential to many production processes. With RT 586 key water parameters can be monitored and controlled.
  Water flows into a transparent tank which contains a stirrer. A sensor allows for measurement of the conductivity of the water. It is displayed on a meter and transmitted as an electrical signal to a controller. The desired conductivity is preset as the reference variable on the controller. The controller influences the conductivity of the water by adding diluted caustic soda with a metering pump.
  The addition of caustic soda causes the pH value of the water to rise. It flows into a second transparent tank. A sensor provides for the measurement of the pH value. The desired pH value is preset as the reference variable on the controller. The water is neutralized by adding diluted sulphuric acid with a metering pump. Another sensor in this tank is used to measure the oxygen concentration of the water. It is displayed on a meter and transmitted as an electrical signal to the controller. The controller influences the injection of compressed air, and thus the oxygen concentration of the water, by way of a control valve. The water flows into a collecting tank.
  The redox potential is controlled in a separate section of the collecting tank. In this section the redox potential is measured using a sensor. The controller influences the redox potential of the water by the addition of iodine solution with a metering pump.
    As a further check of performance, a sensor is employed to measure the pH value of the water in the collecting tank. It is displayed digitally on the switch cabinet. A six-channel line recorder is provided to record the control processes.

  The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

- comparison of various controller types
  * P, PD, PI and PID controllers
  * two-point controller
- influence of caustic soda on electrical conductivity

  and pH value
- influence of sulphuric acid on pH value
- influence of air injection on oxygen concentration
- influence of iodine on redox potential