Fig. 1. Fluorescence spectra of water samples

Fig. 2. Schematic diagram of optical monitoring

Fig. 3. Circuit structure diagram of the sensor

Fig. 4. Physical diagram of circuit module

Fig. 5. Structural design of the sensor

Fig. 6. Framework of online monitoring device

Fig. 7. Physical images of two types of sensor prototypes

Fig. 8. Field test diagram of the sensor

Fig. 9. Test results of deep ultraviolet sensors under different light sources

Fig. 10. Test results of near-ultraviolet sensors under different light sources

Fig. 11. Testing Stability of Sensors under Different Water Sample Concentrations

Fig. 12. Verification results of sensor indicators

Fig. 13. East China Sea test site diagram of the equipment

Fig. 14. Online monitoring data of oil platform

Fig. 15. Online monitoring data graph of abnormal points

Fig. 16. Offshore platform laboratory testing

Fig. 17. Comparison of data between online monitoring and laboratory infrared testing