When lifting the liquids ban, Type D detection equipment seems a practical necessity. By Carroll McCormick.
Scanners capable of quickly analysing liquids, aerosols and gels in carry-on bags will need to be in place at airport security checkpoints, should the European Union go through with its plan to lift the ban on carrying volumes of liquids greater than 100 millilitres on board aircraft on April 29, 2013.
There are four explosive threat detection method classifications (see table): A, B, C and D. Machines capable of A, B and C detection currently exist, but according to conversations Morpho Detection Inc (MDI) has had with European airport security directors, even the most rapid of them – C –is not capable of meeting practical throughput requirements at security checkpoints.
“Type C detects liquid explosives in containers, but they must be removed from the baggage. This is called ‘divestiture’, and the disadvantage is that it takes extra steps,” says Steve Hill, Global Communications Leader for Morpho Detection.
What is required to avoid divestiture and its inherent delay, is a Type D solution, which Morpho is in the process of developing. Steve Hill explained: “This is the Holy Grail: detecting liquid explosives in containers while still in passengers’ bags. In our work with major airports, we understand that only Type D is acceptable. Anything less than Type D would shut airports down, with security lines running out of the doors.”
Think of a low-technology solution: dedicated checkpoint lines for passengers with liquids to divest and priority lines for those without. Considering the endless tonnage of forbidden objects that security officers continue to liberate from passengers more than a decade after 9/11, it is difficult to imagine the priority lines working. They are likely to simply grind to a snail’s pace and remain permanently dysfunctional. Jay Hill, Executive Vice President, Global Strategy and Technology, Morpho Detection, observes: “The debate is really about the operational impact of implementing A, B or C. There are a lot of opinions on whether these technologies are operationally feasible.”
While debate continues over the lifting of the liquids ban, Morpho has been busy developing a Type D scanner called XDi that will meet the technical requirements of the European Civil Aviation Conference for liquids, aerosols and gels detection (LAG). Utilising X-ray Diffraction (XRD) technology, XDi will automatically detect multiple liquid explosive threats inside containers and bags, so passengers do not have to remove permissible carry-on liquids for screening.
Morpho cannot divulge the specific range of explosives XDi will detect, but it will be capable of detecting multiple liquid explosive threats. XRD technology has been used successfully for more than a decade in screening and alarm resolution for checked baggage. “XDi will be capable of detecting and identifying a wide variety of liquid explosives threats, their mixtures and their component substances,” Jay Hill explained.
Company confidence that it can achieve this is due in part to the performance of its XRD-based machines for hold baggage screening. Although there are currently no requirements for liquids detection in checked baggage, Jay Hill notes: “Morpho offers a wide-range of solutions including computed tomography (CT) and XRD-based EDS systems that meet all current regulations.”
Steve Hill said: “We have been working on liquid explosives detection for quite a few years. By utilising X-ray diffraction technology we are confident XDi will facilitate the low false alarm rates and high-throughput needed to quickly move people through airport security lines and checkpoints.”
Jay Hill elaborates: “X-ray diffraction has been used in checked baggage but those requirements are not the same as detection at checkpoints. They are very different. The equipment has the same basic capability but the algorithms we are developing for the checkpoints are for a new set of libraries, driven by the liquid explosives detection requirements, which are specific to checkpoints.”
XRD technology identifies materials based on their molecular composition, not their density or other less distinctive characteristics. In addition to LAG detection, the technology will be able to identify powders and solids. Morpho predicts that within three to five years XDi machines will also be able to detect threats in laptops and smart phones without them being divested – although this estimate is based more on the likely evolution of regulatory requirements than technology capability.
Morpho states that not only will XDi exceed current EU standards for detection of liquid explosives and their components; it is already capable of meeting future security standards, such as in the automatic detection of solid, home-made and/or sheet explosives. Steve Hill revealed the laptop challenge: “The form factor lends them to secreting sheet explosives, which are more difficult than some other types of explosives to detect. Laptops also have components in them that can act as shields – black spots that operators cannot see.”
“Since XDi is built of technology used for checked baggage, it is also very good for conventional requirements. So, beyond the ability to meet liquid explosives detection [requirements] it can detect crystalline solids,” Jay Hill said. “We have the ability to adjust the scope of detection as threats change, to expand a library that will detect more and more substances without generating false alarms.”
Current XRD-based hold baggage EDS machines are monsters that are impractically large for checkpoint application. For example, Morpho’s XRD 3500 EDS machine measures 8ft 4in x 8ft 4in x 19ft 7in (2.5m x 2.5m x 6m) and weighs 21,605 lb (9,800 kg). Similarly, its CT-based checked baggage screening CTX 9800 DSi machine tilts the scales at 16,800 lbs (7,620 kg) and is 7ft 10.5in x 7ft 1.5in x 15ft (2.4 m x 2.17 m x 4.5 m). Scaling down hold baggage equipment to meet space restrictions posed by existing checkpoint lane configurations, as well as potential floor loading restrictions, is a challenge. “We have had to make [the equipment] smaller, lighter and cheaper. We have embarked on aggressive research in the past couple of years to do this,” Steve Hill said.
Checkpoint throughput requirements are also keeping Morpho researchers busy. There are no official requirements, according to Morpho, but airports like to see around 200 passengers per hour passing through a checkpoint lane. Jay Hill said: “The limiting factor is typically not carry-on screening, but the screening of passengers themselves. A checkpoint system should be able to screen up to 500-600 passenger carry-on items per hour, which XDi will deliver.”.
XDi will not be an additional scanner at checkpoints – it is being designed as the scanner. In addition to its automated explosives detection offering, it will include a conventional dual-energy x-ray capability and monitor. This will allow staff to look for other prohibited items, with classes such as metal, inorganic and organic materials highlighted in colours.
In their current role for screening checked baggage, XRD-based machines already provide extremely low levels of false alarms, according to Morpho. The company is confident the false alarm rate will remain extremely low with the smaller and faster machines it is developing, even with their expanded libraries of threats. (The more threats a technology is designed to detect, the greater the likelihood of it generating false alarms). Morpho also sees its XDi research and development leading to faster XRD machines that will be viable as primary explosives detection system tools in hold baggage screening.
The Morpho road map shows the delivery of XDi units for operational testing in 2012 and deployment for operational use in 2013. If XDi is not ready in time for a lifting of the liquids ban, airports may be forced to install Type C machines as interim solutions, moving to Type D successors as they become available.
There are currently several machines certified for Type C liquids threat detection, but Morpho products are not among them. Jay Hill is not unduly concerned: “MDI is constantly evaluating its product offering to ensure we deliver a broad portfolio that meets all regulatory requirements. We are exploring a variety of options to ease any such required transition.”
EDS Method Classifications
|TYPE A||Detection of liquid explosive threats in unsealed container;|
|TYPE B||Detection of liquid explosive threats in sealed container;|
|TYPE C||Automatic classification of multiple liquid explosive threats when out of carry-on bags and in a separate tray for screening (in combination with a conventional
|TYPE D||Automated detection of multiple liquid explosive threats when inside containers and bags.|