Design procedure of ultrasonic tomography system with steel pipe conveyor

• An ultrasonic tomography system for producing the cross-sectional images from metal pipe is designed.
• An optimum frequency for the case of metal pipe is proposed from simulation results.
• The method of extracting of the data signal from receiving signal is described.

Non-invasive ultrasonic tomography has a dominant role in extracting cross-sectional images of objects. The front-end structure of the proposed ultrasonic tomography system with a steel pipe conveyor is explained in this paper. In the novel ultrasonic tomography system presented, a non-invasive sensing technique is applied for detecting gas bubbles inside the steel pipe. A method of visualising the structure of the steel pipe with finite element software (COMSOL Multiphysics 4.2) is also presented in this paper. An appropriate sensor with 40 kHz resonance frequency, based on simulation results, is selected and experimentally mounted on the periphery of the vessel. Several reviews regarding the common tomography technique proposed and hardware preparation are also discussed. Twelve dual-function (transmitter/receiver) ultrasonic sensors with a fan-shaped beam projection capability are used as the sensory part of the system. Details of the circuitry of the system are also presented, which consists of various parts such as a signal generator, signal conditioning and signal acquisition strategy. Finally, the experimental results of the proposed system, which are useful for further investigation for the application of ultrasonic tomography in industry, are illustrated.