Home           Products           Company           Contact us     
> Basic Control Systems
> Components and Calibration
> Process Control Modules
> Process Control Trainers
> Industrial Process Control Systems
> Process Control with PLC Applications
> Automatic Control for Plant and Machinery
> Fuzzy Control
> Mechanical Process Engineering
> Chemical Process Engineering
> Thermal Process Engineering
> Process Plants
Products  |  Process Control and Process Engineering  |  Process Control Trainers  |  RT 681
RT 681 Test Stand for Level / Pressure Control Show data sheet (pdf file) Print page
Technical Description
This high quality test stand enables to perform complex experiments on a multivariable system often used in practice. In this particular case, a vacuum degassing model is used as an example of an interacting two-variable control system. Vacuum and level are the two variables to be controlled in a process tank. Pressure and level are interdependent variables.
The system has a closed water circuit. The vacuum is generated by a waterjet pump with its own water circuit. Two pneumatic control valves control vacuum generation and discharge from the tank. The test stand contains high quality instrumentation. The controllers have a Profibus DP interface. This interface allows the test stand to be monitored by optional process control software RT 650.60. This software can also be used to record process variables and to tune controller parameters via PC.
Learning Objectives / Experiments
- Demonstrating a multivariable system
- Determining system parameters
- Realising non-interacting controlled variables
- Comparing the different controller types: P, PI and
  PID and their suitability 
- Recording step responses
- Investigating control quality
- Investigating stability
Features
* Multivariable control system
* Strategies to realise non-interacting systems
* Controller layout and stability
* High-quality equipment with industrial components
* Profibus DP
Available accessories
RT 650.60 -- Process Control Software for RT 681 - RT 682 Series
Alternative products
RT 682 -- Stirred Tank Test Stand
Specification
[1] Multivariable control system in a mobile steel rack
[2] Combined liquid level/pressure control system
[3] Vacuum degassing process with transparent 20ltr process tank
[4] 2 digital industrial controllers can be configured as P PI, PD, PID
[5] Profibus DP interface
[6] 2 pneumatic control valves DN20, PN16
[7] Capacitive level sensor 0...500mm
[8] Piezo-resistive pressure sensor -1...0bar
[9] Standardized signal 0(4)...20mA
[10] 2 centrifugal pumps 30m, 10ltr/min
[11] Waterjet vacuum pump
[12] Rotameter for process water and air
Technical Data
Level sensor, capacitive: 0...500mm
Pressure sensor: -1...0bar
Float-type flow meter
Process tank: 20ltr
Centrifugal pumps: max. head 30m, max. flow rate 10ltr/min
Supply tank: 70ltr
Control valves: pneumatic, DN20, PN16
Digital controller: Xp: 0...999.9%, Tv: 0...1200s, Tn: 0...3600s
Dimensions and Weight
l x w x h : 1150 x 500 x 1920 mm
Weight : approx. 115 kg
Connections
230V, 50Hz, 1 phase
Scope of Delivery
1 basic unit, 1 instruction manual
Order Details
080.68100  RT 681 Test Stand for Level / Pressure
                     Control
Print
© 2005 G.U.N.T. Gerätebau GmbH