Design and Automation of Gas Measurement System Using Lab VIEW & PLC

Vacuum chambers are very common in the physics experiments. Turbo Molecular pump, pneumatic gate valve (EGV) and Rotary pump are used for evacuating the experiment vacuum chamber. Residual Gas Analyzer is used for measuring partial pressure of gases present in the chamber. All these instruments require a specific operation sequence and control depending on the system requirement. This operation sequence is based on virtual instrument and controlled through a Computer, improving test efficiency. Failure to follow the proper sequence may damage vacuum components resulting in capital loss. The current vacuum system was operated manually by the operator and controlled using different software platforms. The integration of the all these in to one program lead to the choice of NI Lab VIEW software. Another challenge was to identify proper inputs and outputs of the vacuum instruments of different make and having different connections for control. Since the control sequence is slow in nature, therefore for hardware implementation using a PLC was obvious choice and executed in closed loop. The automation also necessitates data acquisition and data logging in Lab VIEW. The partial pressure measurement using RGA was implemented independent of the control sequence using Lab VIEW program. The implementation of the Lab VIEW control sequence operated the instruments seamlessly. The partial pressure data were achieved on the host PC. This research work describes modification of existing manual control into a automatic GUI based computer control system of Gas Measurement System.