Construction of a Labview controlled pyrolysis unit for coupling to a Pyrola 85 pyrolysis chamber

Abstract: Pyrolysis is the process of molecular decomposition in an inert environment using heat. It is possible to fragment large molecules, such as polymers, by pyrolysis and separate the fragments directly in a GC. This makes it possible to form complex sample fingerprints that can be used in various applications, for example in forensic science. In this project, a malfunctioning Pyrola 85 pyrolysis unit was fixed by measuring the voltage signals from the photo diode during pyrolysis in a Labview program. With the Labview program, a partly manual filament temperature calibration procedure was developed, as replacement for the non-working automatic calibration procedure. The functioning pyrolysis unit was then installed on a GC/MS in the National University of Science, Ho Chi Minh City, Vietnam. Plant samples were analysed with the Pyrolysis-GC/MS system as a test of the system, resulting in pyrograms with a few identifiable peaks. However, both pyrolysis and GC/MS settings needs further investigation to optimize the analysis. In Sweden, a Labview controlled Pyrolysis unit was constructed to investigate the possibility of improving certain functions of the original control unit. A proposed Labview program and circuit boards were constructed and partially evaluated. The accuracy and precision of the pulses from the Labview program was