Study On The Instrument Of Concentration In Situ Measurement Of Oil In Water Based On Fluorescence Technology

Oil contaminated to water is serious environment pollution and the water resource is very limit to human, so it is very important that the quality of water is monitored and polluted water is processed.The analysis of oil in water base on the fluorescence is simpler and higher sensitive and easier in situ measurement. And because of this advantage, the fluorescence analysis became research hotspot in the concentration detection of oil in water.This paper research the fluorescence measure way and given a new in situ measurement system.Based on the fundamental theory of fluorescence measurement, this paper demonstrated the oil fluorescence detection principle and the feasibility of all optical fibers and fluorescence method in measuring oil concentration and also this paper describe the advantage of the fluorescence method compare with infrared method that was adopted by GB. All this can be used as the basis of theory and experiment for oil contamination measurement.The paper describe the absorption spectra and excitation spectra and the fluorescence spectrum properties and also selected the best excitation wavelength and fluorescence wavelength. All these were done for selecting excitation light filter and fluorescence filter.The paper studied the spectrum property of the excitation light, described the transmission property of fiber optic and selected photoelectric detector and so on. Described the blueprint of the fluorescence measuring instrument, design the control circuit of signal detection system and also described the system construction of the in situ measurement machine. It looked very suit for doing the real project.Through analysis and research of noise control for in situ detection system, we get a new method for wavelet de-noising that based wavelet entropy. And the de-noised fluorescence spectrum via the wavelet transformation using this threshold method is compared to the de-noised spectrum via the analog low-pass filter . The result shows that the de-noising spectrum via the wavelet transformation keeps more information for the original signa1.So the detection sensitivity of the system will be improved with the aid of this method.