A Hollow Cylindrical Structure Of The Fiber Bragg Grating-based Rotating Coaxial Cylinder Viscometer,

Viscosity measurements is an important parameters in oil cracking, lube oil blending, automatic monitoring the production process of the food and drugs, monitoring pipeline transportation process monitoring crude oil, various inspecting petroleum products and paint quality, testing, analysis, quality and plays an important role in improving production quality, increasing the finished product rate. At present, Viscosity sensor belonging to strain sensor by measuring the strain of various elastic elements indirectly measure the viscosity. Although this sensor has reached a high degree of automation and accuracy, the most use of electrical stimulation and signal transmission, When which is measuring, the measurement is not only susceptible to electromagnetic interference and measurement of flammable liquids can easily lead to fire or explosion caused by spark discharge even if using of explosion-proof treated the existence of the security sensors are also certain risks. Due to the unique capability of electrical insulation give the fiber Bragg grating viscometer the anti-electromagnetic interference (EMI) and in the flammable and explosive occasions Intrinsic Safety. The viscosity measurement based on Fiber Bragg Grating programs have developed rapidly.Fiber Bragg grating sensor technology through the Bragg wavelength shift to obtain, such as stress, temperature, vibration, acceleration and other external parameters. Because of its measurement signal and transmit signals are optical signals, it have no electromagnetic interference and the safety characteristics, so can greatly improve the safety and reliability of measurement. Thus in the field of flow measurement, fiber Bragg grating sensors have broad application prospects.In this paper, using optical fiber Bragg grating as the sensing element, its viscosity measurements for the sensing structure, principles and techniques are studied. The main contents are as follows:1.The use of hollow cylinder-type viscometer and the Suffered in the hollow cylinder torque and viscosity as a certain function. Developed a flexible hollow cylindrical structure of fiber Bragg grating hollow cylinder-type viscometer. The sensor principle is: wavelength of fiber Bragg grating pasted on the hollow column body wall has a linear relation with the torsional strain that hollow cylinder suffered.2. Established the sensor model based on a linear relation between the load speed on the hollow cylinder with the Bragg wavelength shift of hollow cylinder-type fiber Bragg grating viscometer.3. Based on the specific materials and size of this sensor component I have calculated the theoretical sensitivity of this sensor. Theoretical sensitivity is 0.008pm/(pa.s/r/min); the theory resolution is 125(pa.s/r/min)/pm.4. By experiment method, I have obtained the actual sensitivity, speed increasing 0.0089pm/(pa.s/r/min), speed decreasing 0.0083pm/(pa.s/r/min), the actual resolution is 120.482(pa.s/r/min)/pm.