This project involved developing a LabVIEW application that would be used to control an automated vacuum calibration system.
In the current situation the vacuum calibration was carried out manually, this was a very long and tedious task often taking days to complete. A fully automated system would vastly reduce this time and also create more accurate and reliable results.
The hardware side was developed by a specialist in vacuum systems, working together with iNU Solutions we specified the hardware that will be used to control the system. The chosen hardware is listed below:
- NI cDAQ-9174 Chassis (Ethernet)
- NI 9485 SSR Module
- NI 9215 AI MOdule
- NI 9421 DI MOdule
- GranVille Phillips 370 Stabil-Ion Gauge Controller (RS232)
- MKSPR4000B Controller (RS232)
- Edwards TIC Controller (RS232)
- Pfeiffer MaxiGauge Vacuum Display (RS232)
- Yokogawa MW100 DAQ (Ethernet)
- VAT Variable Leak Valve (RS232)
- Windows 7 based PC running LabVIEW 2015
The Automated Vacuum Calibration System
The final solution involves two vacuum chambers and a series of pumps and valves that can be switched individually, or automated as part of a pre-defined “recipe” to comply with international standards. The current status of all the valves and pumps is displayed in realtime on the UI, as well as all pressures, alarm and the current progress of the calibration sequence.
A calibration sequence can be configured in just a few minutes, then left overnight to complete the necessary steps and carry out the required calculations. Once completed everything is placed into a safe state ready for the next sequence to start.
The VAT Valve is used to create a “leak” in the vacuum chamber which – using a PID control method – controls the pressure inside the vessel to the required set point level. This level is maintained for a pre-set time, to ensure an equal vacuum across the chamber and then the necessary data is recorded for analysis.