U.S. Checks Out Money Detectors

Federal scientists are perfecting some new inventions designed to detect cash and even trace bills as they pass through society.

The effort is supposed to root out drug and terrorism money, but some say it’s yet another example of using technology to abuse personal freedoms.

One device sniffs the air for the smell of money -- it can pick up a pile of cash from about 10 feet away. Another beams electrons through packages or luggage to detect trace metals in the green ink. And a third would actually scan serial numbers of individual bills into a database.

Lead scientist Keith Daum at the Idaho National Laboratory said the inventions’ purpose is to intercept cash used in illegal drug or terrorism transactions.

“When Joe the Druggie gets his $20 from an ATM and spends it on a [drug] pickup and the money is later traced to a drug seller -- to me, that’s evidence,” Daum said.

Daum, along with colleagues Tim Roney and Gary Gresham at the lab’s National Homeland Security Division, work in a room that even “Q” of James Bond fame would be proud of.

Digital equipment, glass tubes and boxes with dials are strewn around the secured white-walled lab. Steel tracks allow sections of the room to be moved back and forth.

The machines sit unobtrusively on the counter. Daum gleams as he describes how they work.

The cash sniffer is actually a gas chromatograph about the size of a cordless hand vacuum. Here’s how it works: Take a crisp $20 bill and put it up to your nose. That sweet, slightly acidic aroma is microscopic molecules of ink and paper landing on the nerve receptors inside your nose.

The device works nearly the same way, but with higher sensitivity. Airborne molecules land on a sensor. If enough are detected, the device emits an alert.

Daum said a trained dog can do the same thing -- even better -- but not consistently and not over a long time.

The second device is called the “physics-based” detector. About the size of a small airport X-ray scanner, it scans an interior space for elemental metals used in the green ink. Radioactive rays strike the metals and turn into gamma rays, which are then measured by the machine. The more detected, the higher the volume of cash bills.

Daum said it could be built large enough to scan a shipping container.

The machines were developed with a $1-million annual budget from the U.S. Immigration and Customs Enforcement agency. They are not in production, but are being field tested.

Of course, carrying cash -- even large amounts of it -- is not illegal, although there is a limit of $10,000 that anyone may take into or out of the United States.

Still, intercepting large sums of money would at least put a dent in the drug trade, said Ethan Huffman, spokesman for the Idaho National Laboratory.

“Money is always the incentive to bring drugs across the borders,” he said.

The third project, a relatively new device, is on loan to the laboratory. It looks like a bill counter banks use to tally stacks of cash. But on the back, an add-on box about the size of a file folder reads and stores the serial numbers of every bill it counts. If there were a database of serial numbers, it would be possible to trace money across the globe.

That worries people like Melissa Ngo of the Washington-based Electronic Privacy Information Center. “This is just another step toward a complete lack of anonymity,” she said.

“There are many reasons people wouldn’t want information about where they spend their money, from stopping mass marketers to people thinking it’s nobody’s business what books or CDs they buy,” Ngo said.