Design of the measuring circuit for the content of crude oil in seawater

4th International Conference on Water Resource and Environment

地球科学;生态环境科学

Wu, N.^1 ; Zhang, S.W.^1 ; Ma, H.K.^1 ; Cao, X.^1 ; Chu, D.Z.^1

Institute of Oceanographic Instrumentation, Qilu University of Technology, Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao

266001, China^1

关键词: Application prospect;    Digital lock-in amplifier;    Fluorescence intensities;    Fluorescence signals;    Fluorescent signals;    Laboratory experiments;    Programmable gain;    Simple structures;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/191/1/012126/pdf
DOI  :  10.1088/1755-1315/191/1/012126

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

It has been demonstrated that there must be a linear relation between fluorescence intensity and concentration of crude oil in seawater. Since the fluorescence signal is strong weakness and is also affected by the ambient light & stray light, it must be extremely difficult or almost impossible to detect based on convention ways. In this paper, a new approach for the detection of the weak fluorescence signal by the programmable gain of digital lock-in amplifier (PG-DLIA). The proposed scheme which comprise of the 255 nm LED trigger to excite the seawater to produce fluorescent signal, and the high sensitivity photodiode as detector to perceive of the faint fluorescent signal. In particular, the feeble fluorescence signal is well detected through the circuit of PG-DLIA. In terms of the laboratory experiment and sea trial, the sensor of crude oil in seawater with this circuit has the advantages of simple structure, lower consumption, portable, modular, high precision, real time and continuity. It will have vast application prospects on the detection of weak signals.