Development of a novel ultrasound monitoring system for container filling operations

Food and drink production represents the largest manufacturing sector in th e UK economy and are among the largest UK exporters (pound 8.2 billion in 1 995). 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 m ajor stages of the supply train. Around 45,000 companies are involved in fo od processing and production in the UK, and 90% of these are classed as sma ll to medium enterprises (SMEs) with less than 250 employees. Most of the S MEs possess little, if any research facilities or research expertise. Food processing represents a field of rapid development and implementation of ne w approaches in process technology, in particular, automation systems, qual ity procedures, efficiency improvements and sensor systems for on-line proc ess 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 developin g ultrasound monitoring techniques with sensors positioned at the base of t he container for ease of operation. The objective of the research described herein was to explore various approaches to ultrasound monitoring to assis t determination of the potential benefits of mounting the sensors on the si de and top of containers. Three sensing techniques have been identified and explored, and two methods of signal processing have been assessed to deter mine the optimum approach. The central result of this work was the discover y and utilisation of the non-contact air transmission approach to ultrasoun d sensing. Ultrasound monitoring from the side or top of containers require s a contact approach and therefore is seen as impractical for a high-speed food processing situation. (C) 2001 Published by Elsevier Science B.V.