Posted by: sean | November 4, 2009

Bomb sniffing wands: magic, placebo or snake oil?

snake-oil-cablesIf you’ve ever lived in a city like Beirut or Baghdad, you’ve probably been scanned by a bomb sniffing wand at a checkpoint. Here in Beirut, they’re used at army checkpoints as well as entrances to the parking lot at the mall. I’ve always wondered how these things detect explosives, and I’ve heard that they somehow work by smell.

This has never made any sense to me, and my curiosity was piqued when while driving a friend’s car, I was stopped at the entrance to the parking lot of my local supermarket. The security guard took the wand and walked to the side of the car, the famed Datsun, and as I was getting ready to keep driving as I’ve done hundreds of times before, he asked me to stop. He said that the wand had detected something and wanted to know if I had perfume in the car. I said that I was wearing cologne but didn’t think there were any major amounts in the car. He said that that must be it and then waved me through without actually checking the car.

Needless to say, I was even more confused as to how the wand worked and more than a little disconcerted about the level of security. If all a suicide bomber had to do to get past the bomb sniffer was spray on some imitation CK1, then we’re in for some trouble.

It was with some fascination, then, that I read this piece in the Times today about the conflict between Iraqis and Americans when it comes to these bomb sniffing wands:

The small hand-held wand, with a telescopic antenna on a swivel, is being used at hundreds of checkpoints in Iraq. But the device works “on the same principle as a Ouija board” — the power of suggestion — said a retired United States Air Force officer, Lt. Col. Hal Bidlack, who described the wand as nothing more than an explosives divining rod.

Still, the Iraqi government has purchased more than 1,500 of the devices, known as the ADE 651, at costs from $16,500 to $60,000 each. Nearly every police checkpoint, and many Iraqi military checkpoints, have one of the devices, which are now normally used in place of physical inspections of vehicles.

… The suicide bombers who managed to get two tons of explosives into downtown Baghdad on Oct. 25, killing 155 people and destroying three ministries, had to pass at least one checkpoint where the ADE 651 is typically deployed, judging from surveillance videos released by Baghdad’s provincial governor. The American military does not use the devices. “I don’t believe there’s a magic wand that can detect explosives,” said Maj. Gen. Richard J. Rowe Jr., who oversees Iraqi police training for the American military. “If there was, we would all be using it. I have no confidence that these work.”

The Iraqis, however, believe passionately in them. “Whether it’s magic or scientific, what I care about is it detects bombs,” said Maj. Gen. Jehad al-Jabiri, head of the Ministry of the Interior’s General Directorate for Combating Explosives.

Dale Murray, head of the National Explosive Engineering Sciences Security Center at Sandia Labs, which does testing for the Department of Defense, said the center had “tested several devices in this category, and none have ever performed better than random chance.”

…“I don’t care about Sandia or the Department of Justice or any of them,” General Jabiri said. “I know more about this issue than the Americans do. In fact, I know more about bombs than anyone in the world.”

This, to me, is a sort of psychological experiment. Despite my complete lack of understanding about these devices, I’ve always just assumed that they more or less worked. Otherwise, why would they be so ubiquitous? And maybe that’s the point. Maybe security is based on the assumption that if a checkpoint has one of these detectors, then people will assume that they can’t go through it with explosives. Apparently, the company that sells them markets the devices as being able to detect “guns, ammunition, drugs, truffles, human bodies and even contraband ivory at distances up to a kilometer, underground, through walls, underwater or even from airplanes three miles high.”

And maybe it works as kind of a security placebo-deterrent.  Or maybe, at tens of thousands of dollars a wand, it’s just a way for modern day snake oil salesmen to prey on the governments of developing countries:

To detect materials, the operator puts an array of plastic-coated cardboard cards with bar codes into a holder connected to the wand by a cable. “It would be laughable,” Colonel Bidlack said, “except someone down the street from you is counting on this to keep bombs off the streets.”

Proponents of the wand often argue that errors stem from the human operator, who they say must be rested, with a steady pulse and body temperature, before using the device.Then the operator must walk in place a few moments to “charge” the device, since it has no battery or other power source, and walk with the wand at right angles to the body. If there are explosives or drugs to the operator’s left, the wand is supposed to swivel to the operator’s left and point at them.

If, as often happens, no explosives or weapons are found, the police may blame a false positive on other things found in the car, like perfume, air fresheners or gold fillings in the driver’s teeth.

On Tuesday, a guard and a driver for The New York Times, both licensed to carry firearms, drove through nine police checkpoints that were using the device. None of the checkpoint guards detected the two AK-47 rifles and ammunition inside the vehicle.

During an interview on Tuesday, General Jabiri challenged a Times reporter to test the ADE 651, placing a grenade and a machine pistol in plain view in his office. Despite two attempts, the wand did not detect the weapons when used by the reporter but did so each time it was used by a policeman.

“You need more training,” the general said.

UPDATE: Here’s a blog that I found that focuses on the use of similar devices throughout the world, but especially in Thailand.

 

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