August 30, 2011: The U.S. Department of Defense is issuing a new version of their hand-held explosives detector; the Fido NXT. This version includes new technology and improved design and software. The NXT weighs 1.36 kg (three pounds) and takes five minutes to be ready for use, and resets itself much more quickly than the Fido XT model it replaces. Fido is used for routine checking of people or cargo, while the dogs are used for emergency situations or cases where the scent of the explosives has been diminished by time or weather. Fido has been around for six years, and has undergone several upgrades.

The original Fido XT explosives detector was a 1.22 kg (2.7 pound) device that could detect explosives with the same (or at least close enough) accuracy as a dog. These electronic devices are expensive, at about $22,000 each, but they are small enough to mount on a robot, or, via a cable, a safe distance from the troops. Fido XT first showed up in the combat zone in 2005, and has a good track record.

Trained dogs are still faster and more sensitive at detecting explosives via scent. Fido is the result of one of several efforts to emulate the dog’s ability to detect molecules of explosive material. FIDO was developed by a team of electronic, computer and chemistry experts, to do what a dog's nose does. The battery powered device basically detects explosives via the unique scent explosives give off. Explosives are chemical compositions that are constantly breaking down, and shedding distinctive collections of molecules. Dogs can detect them, so can FIDO. But dogs are usually trained to detect only one type of explosives (usually TNT), and have their bad days. FIDO can detect several types of explosives, and is more reliable and tireless than a dog (as long as you have fresh batteries handy.)

The troops use FIDO to detect explosives when they are searching a building, or examining someone they have captured. FIDO can be attached to a robot, and used to check out for buried roadside bombs, booby traps and what have you. The initial troop tests were so successful, that a new version, FIDO XT was developed, which weighs less, but only four hours on its battery (compared to eight for the heavier version).

Work on FIDO began in 1998, and the device was not ready for troop tests in Iraq and Afghanistan until 2005. Some interesting things were discovered during a year of earlier tests, on patches of ground where explosives were buried and trained dogs competed with FIDO to see who was best. Turned out that the "leaking" of the distinctive scent from buried explosives varied from day to day and depending on weather conditions. In other words, on some days the dogs, or FIDO, could detect a "mine", and other days they could not. But overall, FIDO was at least as accurate as the dogs, and capable to detecting more types of explosives.

Recently, a team of Israeli researchers developed a new, electronic, explosives detector that uses 200 sensors, each for a different molecule, to quickly detect nearly all explosives troops or security forces are likely to encounter. The new device is believed to be more effective than the best bomb sniffing dogs. The new device uses the same techniques the dog does, the ability to identify combinations of molecules explosives emit. The new technology is cheaper, faster, smaller, more accurate and detects smaller traces of explosives than existing electronic explosives detectors. The new sensor is a year or two away from a mass produced device the troops can use.