THE FUTURE OF HAND-HELD EXPLOSIVES DETECTION
Disadvantages of IMS Systems
IMS instruments normally contain a small quantity of radioactive material as an ionizing source. This radioactive source does not pose any health risks if the system is operated properly, but simply having such a source may lead to extra paperwork and regulatory oversight. THE FUTURE OF HAND-HELD EXPLOSIVES DETECTION
The drift time associated with a given ion is dependent on atmospheric pressure, and can thus change during inclement weather or when the spectrometer is moved more than a few hundred feet in elevation. These conditions require little more than routine, periodic recalibration, but users need to be aware of this issue.
Another drawback of IMS technology is peak resolution in mixtures or “realworld samples”. Two different materials that form ions of similar size and mass may appear as a single broad peak rather than two distinct peaks in an IMS spectrum.
Disadvantages of GC/SAW Systems:
The main advantage of GC/SAW detectors is also their biggest disadvantage. The GC/SAW is nonspecific and the presence of other chemicals may make explosives detection more difficult. Additionally, a gas container is necessary for operating the instrument.
Disadvantages of Reagent-based Systems:
The biggest disadvantage of color-based systems is the reliance on the operator’s interpretation of color, as follows:
• Identifying the specific type of explosive present when a positive result occurs is not always possible.
• Only the specific colors in the instructions can be judged a positive detection. Other discoloration is possible, but should be judged negative.
• Operators may have some degree of color blindness.
Additionally, vapor sampling cannot be performed and detection is very dependent on sample concentration.
Disadvantages of GC/MS Systems:
Some MS systems require a gas supply or vacuum pump. The sample analysis time can be relatively long.
Advantages of Luminol Chemiluminescence (Chemilumina)-Based Systems:
It is the only technology capable of detecting the presence of all threat explosives, including ICAO taggants, military plastics and TATP.
* It does not utilize a radioactive ionizing source and thus users can avoid some of the paperwork and possible regulatory oversight that may be associated with detectors that use radioactive sources.
Luminol Chemiluminescence (Chemilumina)-Based Systems look for solvent based as well nitro based explosives (90% of explosives are nitrogen oxide based NO2). The new “Designer bombs” frequently are solvent based i.e., acetone, peroxide etc. It catches them all. The technology for the “detection principle” is Chemiluminescence historically the most proven detection method but only used in labs in machines that cost $400K and are huge and do not go in the field. They are considered scientific testing and analytical equipment.
It’s perhaps the best solution available in a portable device. It is more selective and sensitive than most other solutions.
There are far fewer “false positives” from inaccurate detection of non explosives (false alarms). Usually very advanced software makes it very easy to operate. Portable units are typically quite robust and field worthy. Lasts a lot longer in the field prior to maintenance. Cleans and clears itself after contamination by a rich explosive.
It also does not use any external carrier gas or radioactive source (unlike others). If portability, quick detection and clear, accurate results are crucial, then this is the explosives detector needed. You typically will get extremely fast and stable detection with very high selectivity for explosives and immunity to humidity or contamination problems. This technology detects traces of particulates and vapors, allowing for noninvasive searches of luggage, mail, vehicles, documents and containers.
* Fast and Proven: This technology has proven to be capable of detecting plastic and high vapor pressure explosives rapidly-giving clear results you can trust. Luminol Chemiluminescence is an ASTMEPA standard method for atmospheric monitoring of nitrogen dioxide.
* Sensitive and Selective: It can detect minute traces (low nanogram level) of C-4, TNT, Dynamite, PETN, Semtex, EGDN,DMNB, RDX, ANFO, Amonium Nitrate, Urea Nitrate, Nitroglycerine and TATP, with low false alarm levels and few interferents.Immune to variations in humidity and environmental conditions.
* No Radioactive Isotopes or Radioactivity
* Easy to Use: You want a unit which is ready for operation within thirty seconds from turn on. When necessary,any minimal cleaning should take only a few seconds. The simple push of a button automatically activates the sampling and analysis mode.
Results are displayed on an easy-to-read LCD. This ideal for all non-technical personnel. ICAO taggants and tagged plastic explosives.
Portable Advanced Explosives Detection
* Police & Bomb Squads
* Border Crossings
* Military Defense
* Seaports and Containerships
* Field or Forensic Use
This technology is ideal for:
* Nuclear Facilities
* Embassies or Consulates
* Courts of Law
* Postal Stations
* Corporate or VIP Headquarters
* Federal buildings
* Railway, Bus and Subway Terminals
* Special Events, Leases, Rentals
Future Outlook on Hand-Held Explosives Detection
The explosives detection techniques discussed here are expected to remain the principal techniques for use in law enforcement and other applications for at least the next several years. The expected trend for new equipment is toward more portable, miniaturized units, rather than improvements in sensitivity. The sensitivity of current instruments is already adequate for most applications. The miniaturization of equipment will likely reduce the cost of the equipment. Another possible future trend is to have systems that combine two or more detection technologies into a single system.Go back