PLC-TLBGC PLC Industrial Process Control for TLBGC



The Computer Controlled Gas Laws Unit (Boyle and Gay-Lussac Law), "TLBGC", allows to demonstrate two fundamental gas laws: Boylend Mariotte's Law (isothermal change of state) and Gay-Lussac's 2 Law (isochoric change of state).

See general description

General Description

The Computer Controlled Gas Laws Unit (Boyle and Gay-Lussac Law), "TLBGC", allows to demonstrate two fundamental gas laws: Boylend Mariotte's Law (isothermal change of state) and Gay-Lussac's 2 Law (isochoric change of state).

The unit consists of a rigid frame containing two transparent vessels, that enables to observe the change of state in the test gas (air).

In the first vessel, for investigation of isochoric change of state, the temperature of the test gas is increased by a computer controlled electrical heating element, and the resulting pressure rise is measured. The volume of the enclosed gas remains constant. A valve at the bottom of the vessel allows students to normalize the air in the vessel to room conditions.

In the second vessel, for investigation of isothermal change of state, students use a compressor/vacuum pump to increase or decrease the pressure in a reservoir vessel that moves a "liquid piston" of oil in the test vessel. This piston compresses or decompresses a trapped column of air in the test vessel. If the changes occur slowly, the change of state takes place at an almost constant temperature.

Temperatures, pressures and level are measured by means of sensors. The unit includes two pressure switches and relief valves to ensure the safety of the user.

A PID control enables constant temperature operation by controlling the power of the electrical heating element in the first vessel.

Two solenoid valves and two pressure regulator valves enables to control the level of oil inside the second vessel.

The unit uses air that behaves as an ideal gas within the range of pressures used in this unit.

This Computer Controlled Unit is supplied with the EDIBON Computer Control System (SCADA), and includes: The unit itself + a Control Interface Box + a Data Acquisition Board + Computer Control, Data Acquisition and Data Management Software Packages, for controlling the process and all parameters involved in the process.

Exercises and guided practices


  1. Experimental demonstration of the laws of state changes in gases.
  2. Investigation of the characteristic equation of air P·V = n·R·T at room temperature.
  3. Demonstration of the change of pressure of a fixed volume of air during heating.
  4. Demonstration of Gay-Lussac's Law V ≈ T·Constant for air.
  5. Demonstration of gas temperature change during compression and decompression.
  6. Demonstration of Boyle's Law P·V = Constant for air.
  7. Sensors calibration.


  1. Many students view results simultaneously. To view all results in real time in the classroom by means of a projector or an electronic whiteboard.
  2. Open Control, Multicontrol and Real Time Control. This unit allows intrinsically and/or extrinsically to change the span, gains, proportional, integral, derivative parameters, etc, in real time.
  3. The Computer Control System with SCADA and PID Control allow a real industrial simulation.
  4. This unit is totally safe as uses mechanical, electrical and electronic, and software safety devices.
  5. This unit can be used for doing applied research.
  6. This unit can be used for giving training courses to Industries even to other Technical Education Institutions.
  7. Control of the TLBGC unit process through the control interface box without the computer.
  8. Visualization of all the sensors values used in the TLBGC unit process.
  9. By using PLC-PI additional 19 more exercises can be done.
  10. Several other exercises can be done and designed by the user.