Sensor Optimization For Dual-modality ERT/UTT

Electrical resistance tomography(ERT)is implemented on the basis of the conductivity of the material with the advantages of simple working principle and system structure,fast response and visual detection.Ultrasound transmission tomography(UTT)distinguish different materials by the transmission,reflection,diffraction effect on the boundary of different materials.With sensors of different methods,dual-modality system get more knowledge of medium in pipeline,realizing higher accuracy and wider measurement range.ERT distinguish different materials by the conductivity.UTT distinguish different materials by the acoustic impedance.There is no coupling between electric field and ultrasonic field.The electrodes on the same section with transducers have impact on the ultrasonic propagation.Based on the structure of electrodes and piezoelectric transducers installed on the same section,the influence of ERT electrode on UTT,and the optimization of electrode size and transducers size are made.The thesis includes the following four aspects:(1)The impact of position and number of ERT electrode on the ultrasonic transmission is studied based on the electrical field distribution of ERT and ultrasound field to get the optimal structure of electrode and ultrasonic transducer.(2)Based on the optimal structure of electrode and ultrasonic transducer and the operating mode of ERT and UTT,the distribution of electrical field and ultrasonic field in once motivation is studied and the complementary of electrical field and ultrasonic field is discussed to demonstrate the complementary of bimodal sensors.(3)Based on sensitivity and uniformity of electrical field and ultrasound field,the electrode and transducer sizes are investigated to improve ultrasonic field sensitivity and uniformity in structure of 8 electrodes 8 transducers and structure of 16 electrodes 16 transducers.(4)The size of electrode has influence on both electrical field and ultrasonic field.To study the influence on the fields,the optimization parameters are uniformed.And based on the uniformed parameter,the size of electrode is studied.