Research On Key Techniques Of Liquid Refractive Index Based On Prismatic Optical Fiber Sensor

In the basic research, chemical analysis, pollutants detection, diagnostics, food andsemiconductor manufacturing in fields of liquid concentration to precise measurement. Manydevelopment and products in the process of the final measure, similar to the refractive indexand light absorption measurements optical instruments by more and more application, ofwhich use to measure the concentration of the refractive index liquid became a veryconcerning field, on many occasions, the index of refraction of the measurement be testing thewater and some other solution concentration of an ideal method. The same some chemicalmethod than the simple and cheap, and do not change the solution nature itself.First of all, this design from the refractive index with solution concentration relationship,we analyzed the refractive index method of measuring solution concentration developingsituation of domestic and foreign, determine the measured data and the correspondingmeasuring method.Second, establish solution concentration and the index of refraction of the correspondingrelation, measuring the differential pressure and solution concentration than the correspondingrelationship. According to the usual Fresnel formula in the incident Angle is less than CriticalAngle measure the solution concentration, the measure of no special requirements solution,adapt to the range wide, and the area near the Critical Angle reflective energy with the changeof the Angle is very remarkable, the sensitivity of a measurement is higher, can be directlymeasured and convenient and fast, be helpful for measurement to online direction.Finally, building the optical fiber sensor system, photoelectric conversion system andsingle-chip microcomputer control system, the signal analysis, Establish a propercalculation model, including optical fiber sensing system with double road mode, not onlybenefit to the more and more major is calculated in when we can eliminate noise signal in thetest, so as to improve the accuracy of measurement results. The optical fiber sensor output from the light signal through the photoelectric circuit and amplifying circuit transmission tothe single chip microcomputer calculation system, through the theoretical calculation, andfinally LCD will eventually measurement results through the display. This study the designcircuit simulation and experiment, By the compare of experiment results and theoreticalresults，the correctness of the circuits have been validated．...