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Study Of Fluorescence Optical Fiber Temperature Sensor

Posted on:2007-12-04Degree:MasterType:Thesis
Country:ChinaCandidate:D S WangFull Text:PDF
GTID:2178360182983120Subject:Measuring and Testing Technology and Instruments
Abstract/Summary:PDF Full Text Request
The situations of measurement temperature are specially,it is difficult tomeasure temperature for them,and so the other temperature sensor is searched inall research. The virtues of the fluorescence optical fiber temperature sensor areelectromagnetic interference resisting,little bulk,low transmission loss,corrosion resisting. More and more attention is put on the fluorescence opticalfiber temperature sensor. The main research work is as follows: (1)The luminescence theory of fluorescence material is discussed based onphotoluminescence. Several common fluorescent materials and their charactersare introduced in order to select light source.(2)The basic principle and characteristic of fluorescence measurementmethods are discussed. Based on the fluorescence specific properties of rubycrystal are analyzed,excitation light source,optical filter and optical detector areused reasonably. The coupling between optical fiber with light source and opticaldetector are simply analyzed.(3)Both on time domain and frequency domain, the detection for lifetime ofweak fluorescence signal is studied. Time domain method includes that: timemethods, integration method, data fitting method, several measuring methods offluorescent lifetime are introduced such as: phase and modulation measurement,FFT method, weighted-log method, and these methods are compared throughsimulation experiments.(4)A method for the detection of fluorescence lifetime that uses thetechnology of the phase-locked loop is proposed. With phase-sensitive detectiontechnique and modulation technique in this scheme, the measured fluorescencelifetime is converted to a repetitive signal whose period is directly proportionalto it.(5)The double-channels optical fiber temperature sensor based onfluorescence lifetime is purposed. The system uses the scheme of double sourcesthat relative to fluorescence signal modulated and phase-locked to measuretemperature. The real time measurement of fluorescence lifetime is realizedunder no exciting light and no interference. Weak signal measurement devicesare designed such as: photo detector, filter, and delay circuit, dividing circuit,phase-locked loop circuit and single chips. This system has higher temperatureresolution and response though experiments.
Keywords/Search Tags:optical fiber sensor, temperature measuring, fluorescence lifetime, weak signal detection, phase-locked loop
PDF Full Text Request
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