NQR-160. NQR conveyor-type explosive detector with the capacity of working chamber of 160 liters for luggage and hand luggage control. Dimensions of the opening 600 x 400 mm. The unit is tuned for detection of cyclonite- and TEN-based explosives including plasticbased explosives.

NQR-15. Device for detecting explosives in letters, parcels, and small objects. The working chamber capacity is 15 liters (chamber dimensions: 330 x 130 x 360 mm). The chamber can be used both offline and inline with X-Ray intrascope.

NQR-Based Explosive Detectors for Security Systems

Explosive detectors based on Nuclear Quadrupole Resonance (NQR) are the most promising safety devices available on the market today.

NQR Principle

Nuclei of certain elements (N, Na, Cl, etc.) become activated and absorb energy when they become subjected to radiation of certain frequencies. When they transfer to equilibrium condition they eradiate energy of the same frequency. This phenomenon became known as Nuclear Quadrupole Resonance (NQR).
The NQR frequency depends on what compound the quadrupole element is part of. Thus using NQR certain compounds can be detected and identified.

There is a great variety of explosives. However most of them are compound based. Major components of explosives are:

• Ñyclonite (RDX);
• Trotyl (TNT);
• Penthrite (PETN);
• Octogene (HMX).

All above mentioned agents include Nitrogen-14, which can be identified using NQR technology. NQR frequencies of explosives components lay within the range of 0,5 - 5,5 MHz.
When detecting explosives by means of NQR, detection of explosive can be done on any frequency of any particular agent that is a part of the substance.

Advantages of the NQR Method

• High selectiveness to particular explosive and ability to identify its type. Presence of other substances and mechanical mixing of the explosive with other compounds cannot hide the explosive being detected with a certain wave length;
• When detecting mix-based explosives, detection can be done based on the frequency of any explosive component of the mix. For instance TGA, PVV, EVV and Ñ-1 - Ñ-4, etc. mixes can be detected by cyclonite, which is a part of these mixes;
• Short analysis time;
• Non-contact method unlike explosive vapor detectors or specially trained dogs. NQR method allows for detection of explosives with low vapor densities (for instance plastic-based explosives with cyclonite or TEN) wrapped in leak-proof packaging. Regular detection methods are useless for detecting such explosives;
• NQR method is a non-destructive method of detection. The required tension of the alternating magnetic field is such that electronically stored data is not destroyed;
• NQR method does not require unit calibration;
• NQR method is a radiotechnical method. There are no harmful types of radiation.

NQR-25. Unit for detecting explosives in small hand luggage and such like objects. The working chamber capacity is 25 liters.	NQR-R. Device for detecting explosives in passengers shoes has been developed. The sensor is embedded into the cockpit floor.	NQR-K.The detector for mines and other unknown suspicious objects that cannot be tested otherwise as well as for detection of explosives hidden under clothes. A testing device has been developed.