The Research Of Optical-Fiber Temperature Measuring Set Based On Fluorescence Mechanics

Since transferring and transducing technology of optical fiber has some advantages in practices, fluorescence temperature measuring based on optical fiber is rapidly developed. The fluorescence optical fiber temperature sensor is one of the interested problems that are researched in the field of modern optical fiber sensor technology. The situations of measurement temperature are specilly, it is difficult to measure temperature for them, and so the other temperature sensor is searched in all research. The virtues of the fluorescence optical fiber temperature sensor are electromagnetic interference resisting, little bulk, low transmission loss, corrosion resisting. More and more attention is put on the fluorescence optical fiber temperture sensor. Based on the relevant referrances, fluorescence optical fiber thermometer that is based on Hillbert Transformation is put up with, to achieve the real-time measurement of temperature in special situations.Fluorescence optical fiber thermometer is intensively investigated. Based on the principle of photoluminescence and by using Hillbert Transformation to measure the fluorescence lifetime, phase-locked loop technology is adopted for denoising to obtain higher temperature-measuring accuracy.First, the principle of fluorescence-based optical fiber thermometer is discussed in details. Then the temperature properties of light source and fluorescent materials are characterized and the most suitable light source and fluorescent material are picked out for the sensing system. Facts that exist in the practice sensing system and result in poor repeatability of sensing system are analyzed in details. To solve these problems, a cutting and normalized method is given to describe the degree of the non-exponent of the actual fluoresence curve. Some effective measures to improve the non-exponent of the system are given. The optical path structure and electric circuit are presented elaborately. The characteristics of each parts of the system are discussed in details and a weak current detecting circuit with high speed and low noise is developed. In order to reduce the disturbance of electic, relevant resolution method is proposed. Last the software and hardware structures of one-chip microcomputer are designed to measure and display the lifetime of fluorescence.It is feasible that Hillbert Transformation applies to signal processing of fluorescence temperature measurement. The real-time measurement of fluorescent lifetime can be accomplished, so it has some practical value for the industry and biomedicine.