Gas analysis with laser spectroscopy

摘要

The method involves recording a double-modulation frequency-absorption measuring curve of an absorption line of a gas. A curve form, which is adapted to the double modulation frequency-absorption measuring curve, of a reference curve is determined by selection of a suitable top-to-bottom ratio characteristic. The reference curve is adapted to a double-modulation-absorption curve by adjustment of a Y-scaling factor. The concentration of the gas is determined from the Y-scaling factor of the adapted reference curve.