Laser measurements of ozone absorption cross sections in the Chappuis Band

We have developed a sensitive spectrometer which exploits several He‐Ne laser transitions in the visible for precise, high resolution measurements of Chappuis band ozone absorption cross sections at room temperature. An overall, uncertainty of better than 1% has been achieved through a combination of transducer calibrations and an experimental procedure which unambiguously determines the impurity content of each ozone sample. The cross section near 602.5 nm is (5.16±0.03) × 10 −21 cm 2 /molecule. Our results compare favorably with those from most previous studies in the visible range, although some are clearly lower than this consensus probably due to errors in ozone density measurements.