Spectroscopy offers answer to liquids ban on aeroplanes
Anyone who has travelled by air since 2006 has become tediously familiar with the process of having to sift through one's hand luggage for any gel or liquid likely to cause a security breach.
Most of us have experienced the frustration of having packed our bags, only to realise that there is something in our washbag or elsewhere that contains more than 100ml of fluid or gel.
The fact is, however, that ever since a group of terrorists plotted to bring down passenger airliners with liquid explosives, this frustration has become a fact of all air travellers' lives. However, a new system developed by a British company may offer an answer.
The Insight100 from Cobalt Light Systems is a table-top, container-screening device for use at security checkpoints. It uses a technique called spatially offset Raman spectroscopy (SORS) to measure the chemical composition of liquids, powders or gels within sealed containers rapidly and accurately without touching or changing the sample.
SORS involves the use of a near-infrared laser directed at a test subject at multiple points. A small proportion of the light reflected back at each point is shifted in wavelength by the energy levels in the liquid molecules, the size and nature of which reveals what the substance is. The Insight100 acquires the reflected, shifted spectra before comparing them against a library of SORS signatures, enabling it to determine the presence of hazardous substances and material threats.
The Insight100 can analyse bottles of up to three litres in less than five seconds. The container is simply placed inside the unit and the door is closed. If a threat is identified, an alarm is triggered and the automatic door is locked. If not, the door opens automatically for the next container.
The underlying technology has been adapted by Cobalt from its systems for non-invasive, sub-surface analysis in laboratory, pharmaceutical and industrial applications. It is exclusive to the company and was invented at the Science and Technology Facilities Council's Rutherford Appleton Laboratory.
This process offers clear advantages over alternative technologies, according to Stuart Bothron, Cobalt's vice president, product development. "While other technologies have to operate on the balance of probability, SORS offers a precise and unambiguous chemical fingerprint that is unique to the substance being analysed and which precisely identifies the threat material."
The key benefits offered by this system are its high detection capability, low false alarm rate and high throughput. Stuart Bothron points out that these factors have to be balanced to see the true effectiveness of the system. He says: "Our system is fast, but it's not the fastest out there. There is one that's faster. However, most of its competitors have false alarm rates in the 'teens, whereas ours is less than 0.5%. So when you consider the delays brought about by false alarms on more than one in ten items put through a machine, the sheer speed of processing items is far from the most important thing."
The UK Government and the EU are currently working on plans to ease the liquid ban in 2013. As one of the few machines to have achieved the European Civil Aviation Conference (ECAC): Type B Standard 2, which allows it to be used as an alarm resolver in conjunction with existing X-ray scanning systems or as a stand-alone screener, the Insight100 is well-placed to capitablise.
The system has undergone extensive testing at a range of airports across the world, the feedback from which Bothron describes as "very positive".
