| In recent years, optic fiber sensing technology is one of the hot areas of industrial measurement. In some industrial environments, due to very poor measurement environment, the traditional electric sensor could not fillful the demand well. Optical Fiber Sensor Technology With anti-electromagnetic interference, corrosion resistance, flame proof and other outstanding advantages, began to be widely used.In the industrial field, temperature is one of common and important physical quantities. As temperature ranges 800℃-1600℃measured using platinum rhodium thermocouple, it is easy to corrode in chemical environment at high temperature, and it does not have a long work time, besides it is expensive. Therefore in some harsh environment, the traditional way can not measure temperature effectively. This thesis based on high temperature measurement and optical fiber sensor technology, take a study of ordinary multimode fiber optical fiber and sapphire colorimetry pyrometry technique.This article describes in details the theory of colorimetry and optical fiber thermometer application. Colorimetric method ca reduce emissivity and other environment distrub on temperature greatly. In the best conditions, the impact can be reduced to zero. This paper introduces multi-mode fiber contact-non-contact colorimetry temperature measurement technology in sulfur furnace, hot stove, coke oven and other industrial fields.Sapphire optical fiber having a high melting point and high temperature, excellent chemical resistance, and the operating wavelength range, is the most suitable waveguide materials in the high temperature measurement now. The paper focuses on the experiment using sapphire fiber, which takes place in furnace by colorimetry way and calibration data. Sapphire fiber colorimetric pyrometer includes three main sections that are temperature sensing fiber and transmit fiber, photoelectric conversion and data acquisition, signal processing software. For the sapphire fiber length is limited, expensive and difficult to bend, we use a multimode fiber and sapphire optical fiber coupling method to avoid these drawbacks. Photoelectric converting circuit turns the optical signal coupled to multimode fiber into electirc signal. The data acquisition circuit and the MCU do the ratio of data, show the temperature, and finally arrive at an accurate temperature. This paper introduces the application of sapphire fiber colorimetry temperature measurement application in the industrial fields-on line monitoring petrochemical industry, coal gasifier operating temperature. The result shows that the temperature of furnance can be measured in real time under adverse circumstances of produce gas. It can come to a conclusion that the study of this paper can solve some real problems in industrial fields.The main work I have done:①Researching on multi-mode fiber contacts-non-contact colormerity temperature sensor used in the chemical, metallurgical and other industrial fields of temperature monitoring.②Taking a deep study on sapphire fiber including:including sapphire polishing, temperature characteristics, dual wavelength and the intensity ratio between the temperature, and Multi-mode fiber coupling.③designing the "Sapphire fiber probe, contact-general non-contact multi-mode fiber transmission" high temperature fiber temperature sensor, and making it applied to measurement of high temperature coal gasification. |
