Ion molecule reaction mass spectroscopy method for gas analysis

摘要

The method, determining the concentration of particular atoms or molecules in a gas mixture, is based on the ionisation of the molecules in a reaction chamber (5) into which the gas is fed before reaching the spectrometer. The high kinetic energy of the primary ions and high collision energy between the ions and the neutral atoms or molecules must ensure sufficient signal intensity. This is achieved by maintaining a constantly lower potential difference between the optical elements (66,77) of the spectrometer and the ion optic device (4) of the reaction chamber, thus avoiding a potential barrier and ensuring that the products of the chamber are fully drawn down. This gives reliable ion molecule reaction (IMR) spectroscopy measurement.