Device for determining gas concentrations in investigation volume e.g. clean room used in semiconductor manufacture, has beam steering unit that steers beam from radiation source on spectrometer over beam paths between deflection units

摘要

The device has radiation source (Qu) producing electromagnetic beam (ST). An evaluation unit determines two-dimensional concentration distribution for gases in investigation volume based on beam guides spectral analysis performed by a spectrometer (S). Four beam deflection units of beam steering unit are spaced apart at specific distances and moved in observation plane orthogonally to beam axes, to adjust beam guide. The beam steering unit is arranged so that beam from radiation source is steered on spectrometer over two different overall beam paths between deflection units.