Fig. 1. Schematic diagram of laminar distribution in the flow tube

Fig. 2. System diagram of synchronous photolysis of H₂O and O₂.

Fig. 3. Schematic diagram of O₃-CRDS.

Fig. 4. (a) When the instrument only samples zero air, the black point represents the average data of 1 s, and the red point represents the average data of 30 s; (b) Allan variance of ozone concentration.

Fig. 5. Measurement results of ozone concentration distribution factor P.

Fig. 6. (a) Light intensity at 185 nm as a function of N₂O concentration; (b) relationship between light intensity and ozone concentration.

Fig. 7. Concentration of OH radicals produced by the calibration device corresponds to the fluorescence count of LIF-OH system.

Fig. 8. Calibration results of LIF-OH instrument by OH radical calibration source under field conditions.