Process Tomography for Contamination Detection in Liquid Foods: A Feasibility Study

GT Bolton and U Sharif

Industrial Tomography Systems, 47 Newton Street, Manchester, M1 1FT, UK, gary.bolton@itoms.com

ABSTRACT

This paper presents the preliminary testing of the ITS P2000 electrical tomography instrument for contamination detection in liquid foods. Results will be presented showing the detection level of the P2000 system for a range of phantom foreign bodies such as metal and plastic spheres and rods in a liquid food product using a conventional 16-electrode sensor. The range of possible foods and contaminants is wide and this work attempts to quantify the measurement challenge for a number of foods and contaminants.

Further work identified the challenges in applying electrical tomography to contamination detection in liquid foods. The experimental work included optimising system sensitivity for measuring infrequent occurrences of foreign bodies in a flowing fluid. This was achieved by addressing the following technical areas:

• electrode design issues such as size, shape and positioning

• instrument electronics to optimise the speed of data acquisition

• data processing to maximise the signal-to-noise ratio of acquired data

An automatic reference measurement updating routine was added to the ITS software and a novel sensor that could be used in conjunction with the ITS P2000 instrument and software was designed and manufactured. Preliminary results from these are presented.

Keywords electrical tomography, food, contamination, foreign body