Industrial Process Tomography - Platform II grant funded by EPSRC

FACULTY OF ENGINEERING

 

Fast Speed Tomgraphy

New process characterisation from dual 1000+ images/s

A new high-speed electrical impedance tomography has been developed for on-line imaging of two-phase flows. The system is designed in a modular form; it consists of several data acquisition and computing modules. The sensing interface exploits a novel current switching scheme designed to overcome transient delays due to coupling circuits. The computing modules feature a TMS320-series digital signal processor (DSP) which provides a fast IEEE1394 link to a host computer (Fig.1). A speed of 1164 dual-frames per second (2.383 x 106 data points) is attained with RMS error of less than 0.6% (demonstrated at 80kHz in a static test) [1].

Several DSP modules can be pipelined to support a range of tasks; from fundamental tomographic image reconstruction, to flow velocity estimation (Fig. 2). Features of high speed, and the ability to image complete complex impedance components, provides new capabilities to address major emergent challenges in process applications (Fig. 3). The instrument can be applied to both scientific measurement and industrial monitoring and control [2].


Fast EIT System
Figure 1: System structure [1]

Fast EIT System
Figure 2: Visualization of two bubbles flowing through two adjacent sensing planes [2]

Fast EIT System

Figure 3: Amplitude (middle column) and phase images (right column) of a plastic (top row), metal (middle row) and banana (bottom row) and their set-ups (left column) [2].

Author Information: Mi Wang, Institute of Particle Science and Engineering, School of Process, Environmental and Materials Engineering, Email: m.wang@leeds.ac.uk

References:
[1] Wang, M., Ma, Y., Holliday, N., Dai, Y., Williams, R.A. and Lucas, G. (2005) “A high performance EIT system”, IEEE Sensors Journal, Vol.5, No2, 289-299.
[2] Schlaberg, H.I., Jia, J., Qiu, C., Wang, M. and Li, H. (2008) “Development and application of the Fast Impedance camera- a high performance dual-plane electrical impedance tomography system”, in Proceedings of 5th International symposium on Process Tomography, Zakopane, Poland