Introduction To The Working Principle Of Drug And Explosive Detector

- Mar 05, 2018-

Introduction to the working principle of drug and explosive detector


The explosives narcotics detector can detect objects, including explosives, drugs and prohibited chemicals, without opening the outer package of the detection objects. Its main users are airports, police, customs, prisons, public security and government departments, which are used for security checks. The items to be detected are:


² Search illegal drugs


² Check on passengers, luggage and parcels to see if they are carrying and hiding a variety of Different Explosives


² Forensic analysis of the scene of the explosion


² Detection of underground unexploded ordnance


Explosive exhaledgasapparatus trace vapor can sniff out explosives issued, it is used to detect explosives and other weapons, mainly used in the postal system for mail does not open the inspection, airport and customs of passengers do not contact the check and check the baggage not open packet inspection, and public security, army of residence, vehicles, roads and public inspection. It takes advantage of the fact that all solids have the principle of releasing trace steam into the air, and has high detectability for explosives without metals and explosives disguised as general goods.


Working principle

Ion transfer spectroscopy.

It is a basic "ion migration spectrum" (IMS) detector. The samples to be analyzed are heated to make the collected chemicals vaporized. Then, after gasification, the chemicals are taken into a reaction area by a clean dry air flow as a carrier. The reaction zone has a weak radioactive ionization source, that is, a nickel 63 (63Ni) beta - ray emitter. The beta particles collide with the gas particles in the sample flow and form positive ions and negative ions. Explosive forming negative ions, most drugs such as heroin and cocaine form positive ions.


An electric field is applied along the whole length of the IMS. The polarity of this electric field can be positive or negative, determined by the type of the detected substance. The correct polar ions are allowed to move from the reaction zone to the drift zone through a controlled opening.

Different ions drift at a different, but specific speed, and reach the collector's electrode in different drifting times. In this way, three kinds of ions with different mass (X, Y and Z) will generate the drifting pattern, or wave pattern. On this map, X ions first arrive and the drift time is the shortest.


Introduction of ITMS principle

The full name of ITMS is ion, where I indicates fast ion mass spectrometry, flow trap, t for capture, m for drift, s for mass spectrometry, and Chinese translation for ion trap drift mass spectrometry.


The working principle is: through the method of vacuum adsorption or wipe the entrance will trace explosives collected explosives detector, heated and gasified, combined with special chemical reagents, the trace of radioactive source, chemical ionization reaction. Samples of charged molecules ionized by field ionization ionization into the door, the door later, the polar target accelerated to drift on the sample collector, and record the time of flight of ion in the electric field. Because the ionization of charged molecules of different substances and different characteristics, different molecular weight, so the arrival of polar target time is different, according to the ion flight time records, the judgment of the matter component.


T (TRAP), the trapped ion detection technology for ion rail instruments's patented technology, in the design of a high speed can increase its open door to ionization, ion bunches into the field, and were recorded in their flight, the computer will record these logical overlay to to eliminate the noise in the process of recording, increase the correctness of the effective signal, thus greatly increased the sensitivity, reduce the rate of false positives.


Another patent technology of the explosive detector is a semipermeable membrane increased in the front end, it can effectively block the impurity in the external environment interference on the instrument, only need to allow the matter through, thereby reducing the false alarm rate instrument and shorten the instrument cleaning time, reduce the consumption of impurity suppressor at the same time. In front of semipermeable membrane can also play a useful role in aggregation, adsorption material, this can also improve the sensitivity of the instrument.