Development of a novel ultrasound monitoring system for container filling operations

Food and drink production represents the largest manufacturing sector in the UK economy and are among the largest UK exporters (pound 8.2 billion in 1995). The industry makes essential contributions to UK wealth creation, to the quality of life within the UK and is seen to add value at each of the major stages of the supply train. Around 45,000 companies are involved in food processing and production in the UK, and 90% of these are classed as small to medium enterprises (SMEs) with less than 250 employees. Most of the SMEs possess little, if any research facilities or research expertise. Food processing represents a field of rapid development and implementation of new approaches in process technology, in particular, automation systems, quality procedures, efficiency improvements and sensor systems for on-line process monitoring and control. The current research programme has been set up to develop an ultrasound monitoring system for container filling. For fluid level measurements, most of the previous research has focused on developing ultrasound monitoring techniques with sensors positioned at the base of the container for ease of operation. The objective of the research described herein was to explore various approaches to ultrasound monitoring to assist determination of the potential benefits of mounting the sensors on the side and top of containers. Three sensing techniques have been identified and explored, and two methods of signal processing have been assessed to determine the optimum approach. The central result of this work was the discovery and utilisation of the non-contact air transmission approach to ultrasound sensing. Ultrasound monitoring from the side or top of containers requires a contact approach and therefore is seen as impractical for a high-speed food processing situation. (C) 2001 Published by Elsevier Science B.V.