CLC 36 Closed-loop liquid level control/ flow-rate control

CLC 36 Closed-loop liquid level control/ flow-rate control 

"Closed-loop liquid level control" is a practice-oriented experiment set in applied control technology designed especially for didactic purposes. Due to immediate, visible nature of the controlled variable, i.e. "the level of the liquid", liquid level control is an extremely graphic experiment and is thus particularly well suited for an introduction into automatic control technology. The controlled system or liquid level basin is characterised by the fact that it has a medium response time. Thus experiments can be performed rapidly and the student can simultaneously monitor how the experiment is proceeding. The experiments focus on determining the most important parameters of controlled systems with compensation and the set-up and optimisation of control loops with continuous and discontinuous controllers. The liquid level basin has a plain form on which the foils can be attached to facilitate the marking of the liquid level as a function of time. The character of the controlled system can be modified by using various sliding partitions (delays of the 1st and 2nd order). 4 different outlet drains can be set on the filling basin and the inlet can be set as desired either using an ascending pipe or versus the filling pressure. Because of its modular design, the training system can, with the corresponding supplements, also be used for automatic flow-rate control and to explore measuring techniques. 

Automatic liquid-level control 

• Set-up, putting into operation and optimising an automatic liquid-level control with variable controlled system characteristics 
• Two-position controller in an integral-action controlled system of a higher order 
• Two-position controller with delayed feedback in a closed-loop liquid level control system 
• Two-position controller with float switch 
• PI and PID controller in a closed-loop control system of the first and higher orders 
• Automatic liquid level control with disturbance variable forward feed and precontrol 

Automatic flow-rate control 

• Set-up, putting into operation and optimising an automatic flow-rate control with variable controlled system characteristics 
• Operating principle, response and application of flow-rate measurement 
• Investigating automatic flow-rate control with PI or PID controller and system response to disturbance and reference variable step changes 
• Operating principle and use of step controllers and closed-loop flow-rate control with step controllers