Study Of Fluorescence Optical Fiber Temperature Measuring System Based On LabVIEW

In this paper, on the basis of the fluorescence temperature measurement mechanism, the temperature characteristics of fluorescent materials were theoretical analyzed and the temperature measurement system was studied by detecting the fluorescence lifetime to measure the temperature that can penetrate deep inside the measured object. As the fluorescent fiber optic temperature sensor has accurate temperature measurement, high resolution, anti-electromagnetic interference characteristics, the system can be reliably applied to strong electromagnetic interference environment and inserted into body to measure temperature. Combined with the virtual instrument technology, Host Computer can control and Communication with Data Acquisition System Single-Chip. The virtual system has beautiful interface, easy operation, can monitor the process of temperature measurement real-time on line and save data, which makes the whole system's automation and intelligent. The main research work of this paper is illustrated as follows:First of all, according to domestic and overseas status of fluorescence optical fiber temperature sensor, and starting from the production mechanism of fluorescence, based on working mechanism of the fluorescence temperature measurement, the method of fluorescence lifetime was used to measure the temperature was determined because of the temperature dependence of fluorescence lifetime. The fluorescence excitation and emission spectra were systematically studied, and the range of 20℃~70℃temperature-sensitive of fluorescent material and the suitable measurement method were selected by comparing the argument.Secondly, according to the fluorescence characteristics of fluorescent material, the overall structure of fluorescent fiber optic temperature measurement system was designed, and the selection of suitable fluorescent probe that can efficiently collect the fluorescence signal. And the optimal combination of optical system configuration was studied. And the pairs of reference signal phase-locked loop detection technology was selected to be used for detection of the fluorescent signal. After that, the light source driving circuit was analyzed and designed. The acquisition and processing system about a weak signal was studied. In order to ensure the temperature measurement system with good repeatability and accuracy, in this system, according to the function and optical characteristics of the various devices in the system, the low-noise and high-speed weak signal detection circuit was designed. According to the general performance analysis, select the appropriate data acquisition chip and processing methods to collect the signal data.Finally, according to the temperature detection circuit for programming, the communication circuit was designed and the virtual instrument software: LabVIEW was used to design the interface of virtual system, so that Host Computer communications with the singlechip normally. The signal will be collected and transferred through the computer serial port that was processed and displayed on Host Computer. The software system will make great progress on efficiency of dealing with operations and improve measuring accuracy of the whole system. In addition, the interface of the virtual system is beautiful and easy to operate, which makes the temperature changing monitored real-time online.