COBEM99

SR18 Métodos Experimentais em Termofluidodinâmica

Title:

TÉCNICA EXPERIMENTAL PARA MEDIÇÕES SIMULTÂNEAS DO ÍNDICE DE REFRAÇÃO DE MEIOS FLUIDOS, EM TEMPO REAL

Summary :

IN THIS WORK, A TECHNIQUE FOR MEASUREMENT OF THE REFRACTION INDEX OF FLUIDS, UTILIZING OPTICAL FIBERS, IS PRESENTED. MEASUREMENTS IN DIFFERENT PLACES CAN BE TAKEN, SIMULTANEOUSLY, IN REAL TIME, CAUSING MINIMAL PERTURBATION IN THE MEDIUM. IT IS TAKEN ADVANTAGE OF THE OPTICAL FIBER FLEXIBILITY IN BUILDING AN OPTICAL REFRACTOMETER, PORTABLE, CAPABLE OF TAKING MANY MEASUREMENTS. REFRACTION INDEX VARIATIONS, ASSOCIATED WITH SIMULTANEOUS CHANGES IN OTHER PHYSICAL PROPERTIES SUCH AS, FOR EXAMPLE, TEMPERATURE, ALLOW CORRELATIONS THAT CAN INDIRECTLY YIELD TO IMPORTANT PROPERTIES LIKE DENSITY AND CONCENTRATION. THIS TECHNIQUE IS BASED ON THE DETERMINATION OF THE FRESNEL REFLECTION, STARTING FROM THE KNOWLEDGE OF BOTH THE OPTICAL FIBER AND MEDIUM REFRACTION INDEXES. THE REFLECTED LIGHT IN THE FIBER-MEDIUM INTERFACE STRIKES IN A PHOTO-DETECTOR, IN WHICH ITS RESULTANT ELECTRICAL SIGNAL IS AMPLIFIED AND READ BY A VOLTMETER. FURTHER, IT IS SHOWED IN THIS WORK, A STUDY ABOUT THE STABILITY OF THE REFRACTION INDEX WITH TIME, AS WELL AS AN EXAMPLE OF PRACTICAL USE OF THIS TECHNIQUE.

Author :

Braga, Sergio Leal
Stampa, Cleyton Senior
Szwarcman, Maises H.
Valente, Luis Carlos Guedes

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