Fresnel-reflection-based fiber sensor for on-line measurement of solute concentration in solutions

Abstract A fiber sensor with a simple structure for measuring solute concentration in solutions is presented. The sensor uses only a diode laser as light source, three couplers, two sensing fiber ends with protective cladding, and two photodetectors. The measurement principle is based on relative Fresnel reflective intensity. Various concentrations of salt solution and sugar solution are measured in the setup. The measured data are fitted to linear equation very well and the values of R2 are more than 0.995. Applying the relative technique, the errors resulted from fluctuation of light source and influences of environment are effectively eliminated, and the stability for long time measurement can be improved.

[1]  Chang-Bong Kim,et al.  Measurement of the refractive index of liquids at 1.3 and 1.5 micron using a fibre optic Fresnel ratio meter , 2004 .

[2]  Jian-Neng Wang,et al.  Studies on measurement of chloride ion concentration in concrete structures with long-period grating sensors , 2006, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[3]  J. Longtin,et al.  Real-time precision concentration measurement for flowing liquid solutions , 2000 .

[4]  LI Xiao-mei.  Liquid testing using fiber drop sensors , 2006 .

[5]  Yinian Zhu,et al.  Measurements of refractive index sensitivity using long-period grating refractometer , 2004 .

[6]  Thomas Boehme,et al.  New SPR sensor for refractive index and chemical sensing , 1999, Other Conferences.

[7]  Jianan Y. Qu,et al.  Application of laser Raman spectroscopy in concentration measurements of multiple analytes in human body fluids , 1998, Photonics West - Biomedical Optics.

[8]  Bo Zhang,et al.  Experimental research and analysis of salinity measurement based on optical techniques , 2003 .

[9]  Gabriel Somesfalean,et al.  Concentration evaluation method using broadband absorption spectroscopy for sulfur dioxide monitoring , 2006 .

[10]  Zu-Hong Lu,et al.  Time-resolved photoacoustics for glucose concentration measurement: theory and experiment , 1999, Other Conferences.

[11]  Mitsuhiro Fukuta,et al.  Concentration measurement of refrigerant/refrigeration oil mixture by refractive index , 2004 .

[12]  Anna Grazia Mignani,et al.  Long period gratings as solution concentration sensors , 2001 .

[13]  Kun-Huang Chen,et al.  Normal incidence refractometer , 2003 .

[14]  Liquid concentration measurement based on the optoacoustic effect and fiber Bragg grating sensor technology , 2006 .

[15]  Nicole Jaffrezic-Renault,et al.  SPR fibre sensor sensitised by fluorosiloxane polymers , 2001 .