Studies Of Optical Fiber Thermometer Based On Fluorescence Excited By Ultraviolet

A fluorescence-based optical fiber thermometer with double optic paths is introduced in this thesis. The principle of the sensor is based on fluorescence intensity of materials that monotonously depends on temperature. In the sensor system, an improved double optic paths compensating method is applied to improve accuracy and repeatability. The sensing system not only can be embedded in objects to detect temperature, but also applied reliably to conditions with strong electromagnetic disturbance such as microwave, high voltage and high current.Based on the investigation of relevant literatures, the principle of fluorescence-based optical fiber thermometer is discussed in charter 2. Then the temperature properties of ultraviolet LED and fluorescent materials are characterized and the most suitable ultraviolet LED and fluorescent material are picked out for the sensing system, and a mathematic model of the sensor is proposed. Facts that exist in the practice sensing system and result in poor repeatability of sensing system are analyzed in details. To solve these problems, several representative compensating methods are compared and a constant temperature difference compensating method is developed. The optical path structure and electric circuit are presented in charter 4 and charter 5. The characteristics of each parts of the system are discussed in detail and a faint current detecting circuit with high speed, wide gap and low noise is developed. In order to reduce the disturbance of electric, relevant resolution is proposed. To enhance the substantive data dealing ability and further improve the measurement accuracy, a virtual instrument developing software is adopted. By using of this tool, the acquired data files automatically saving and deleting is realized in LabVIEW environment. Finally, a prototype setup of fluorescence-based optical fiber thermometer is finished.