The study of intelligent temperature measurement based on optic fiber

Abstract

The Sagnac loop mirror of high birefringence fiber is developing greater more than other fiber because it has the advantages of high precision, wide spectrum and simple structure in applications. In this paper, general theory of Sagnac loop mirror of high birefringence fiber is presented. Since Sagnac loop mirror of high birefringence fiber is more sensitive to its environmental temperature, an intelligent temperature measurement system based on Sagnac loop mirror of high birefringence fiber is designed. A 1550nm-laser is used as source light going through the high birefringence fiber Sagnac loop mirror. The amplitude of output beam is converted into electrical signals with Photo-Diode (PD), and the signal is collected by the MCU(Microcontroller Unit) to complete the analog-digital conversion. After calibration, the temperature is calculated, and then shown on LCD displayer. Various parts of the electronic measurement system are introduced in details, containing MCU C8051F020 with microcontroller, its internal AD-convert, calibration program and measurement program of temperature.The fiber optic temperature measurement system is compact, solid with good portability, as well as independent real-time analysis of data processing capability. It’s provides a good preliminary basis for implementation the new fiber-optic temperature measurement system. And this system has broad application prospects of a good practice. The arrangement of temperature measurement is from 30°C to 50°C with accuracy ±0.2°C in recent research experiment.