Liquid Explosives Detector

I guess you have heard about the recent news of the "terrorist plot". Apparently there are some experts from Rapiscan Systems, part of OSI Systems Inc, coming out with gadget to detect the liquid explosives. But don't get too excited with it yet as the cost involved and logistical issue present challenges for these devices.

Homeland security analyst Brian Ruttenbur of Morgan Keegan Co. also points out that the technology still produces a relatively high number of false alarms.

For those reasons — and because there still has not been a successful attack using liquid explosives — Ruttenbur believes the TSA won't be pressed to overhaul the current screening regimen.

That would mean a continued reliance on systems not designed to stop liquid explosives. Metal detectors figure to remain the primary method, with the main secondary screening coming from "puffer" technology that blows air on people and sniffs the particles that emerge for suspicious materials.

For a machine to detect explosives in liquid or solid form, it bombards an object with energy — such as radio waves or neutrons — and in seconds measures the reaction, a response that differs depending on the material's chemical properties. Software in the machine is programmed to alert screeners if it detects chemical signatures known to match those of dangerous materials.

A key question, though, is whether this kind of detection system can realistically block terrorists from bringing seemingly innocuous liquids past security and combining them later to deadly effect.

Certainly, some common ingredients in liquid explosives can be programmed into the detector. But Kant, at Rapiscan, said he would not discuss the vulnerabilities of that approach. "Whether it detects the components of explosives and which ones, there's no way I'm putting that in print," he said.