<p>Identifying polymer materials in the sorting of plastics involves focusing a pulsed high-performance laser ray on the material to be inspected. A short-lived hot plasma is generated and the emission of this plasma is copied optically onto the entry gap of a spectrometer in which the plasma light is scattered into its spectral parts. A multi channel detector registers a specific spectral range on the exit plane of this spectrometer and converts the optical signals into electrical ones. The intensities of molecule bands of diatomic compounds contg. C, H, N and O are registered and transmitted to an evaluator computer.</p>
