Development and Implementation of Gamma-ray Tomography for Field Applications

M W Darwood1, M Davies2, D Godden1, P Jackson1, K James1 and E H Stitt2

1 Tracerco, Pavilion 11, Belasis Hall Technology Park, Billingham, Cleveland, UK 2 Johnson Matthey Catalysts, PO Box 1, Billingham, Cleveland, TS23 1LB, UK hugh.stitt@matthey.com

ABSTRACT

The use of tomography has hitherto been substantially confined to the laboratory and the idealised development environment. This paper reports on the development of a practical γ-ray tomography system that can be used commercially as a process diagnostic tool.

An empirical development program was undertaken on a 40 cm diameter steel vessel. Phantoms and ab intio tomograms were used to allow simple evaluation of the quality of the measured tomogram. Image reconstruction is based on an error minimisation approach. At the relatively low total number of scans to be used, fan beam is significantly superior to grid scanning, in terms of definition and avoidance of ghost images.

Proprietary method development has now delivered an economic, portable, commercial product that can be used to measure tomograms of equipment on manufacturing sites. A case study is presented of the imaging of a 6.2 m diameter packed distillation column.

Keywords Tomography, Process diagnostics, Commercialisation, Industrial