Neotronics Technology Plc of Bishops Stortford, Hertfordshire has announced the latest version of its olfactory sensing equipment known as the Electronic Nose. The e-NOSE 4000 uses neural networks to analyse each odour. A sample impregnated with the odour is placed in a metal cube containing a small chamber which is hooked up to a personal computer. The cube has thousands of individual conducting polymer sensors one centimetre in diameter which are mounted on a silicon wafer. The sensors send olfactory data to a personal computer. The data is collated and then analysed by neural networks. The results of the sample can be presented as a graph or figures. According to John Warburton, marketing manager for the company, the new version produces more reliable results over a longer period of time. This is due to the fact that it has a lower rate of standard deviation which means that marginal differences in smell, such as the difference between the smell of a apple that is perfectly fresh and one that it is past its best can be accurately predicted. And when the test is carried out again the same result is predicted within a very narrow band. Analyses of batch samples for quality control is one of the most commonly used applications for the Nose. It is also used for substances that don’t give off an odour, Warburton said. For example it can detect the level of propylene glycol, a carrier of flavour compounds in food, which can cause an unpleasant taste if over used. It is also used by tobacco companies and the chemical industry. Warburton said that the new system produces results that are 99.8% accurate. Neotronics said that sales of its first generation noses continued to rise and amounted to #300,000 for the financial year to September compared with #92,000 in the first half. The company said it had received #75,000 of orders in October alone. A single e-NOSE 4000 system costs #32,000.