Standoff detection instruments

Quality control on detection equipment presents problems from improvements and modifications to the original instrument to the question of how to check the performance of a deployed instrument. In an airport or seaport environment, screening of cargo remains an unsolved problem. In areas of conflict or terrorism, remote (standoff) detection remains a much sought-after goal [19-20]. 

A relative newcomer to the atomic emission instruments commercially available, LIBS has some significant advantages over the other emission techniques and over ICP-MS and XRF. It is virtually nondestructive and often can be used with no sample preparation. It has the ability to detect all of the elements in virtually any sample type. Versions are available that are field-portable, and versions are available for remote/standoff analysis. Instrumentation is relatively inexpensive. The major disadvantage is the lack of LIBS spectral libraries for easy fingerprint matching, but that is being remedied as the instrumentation becomes more common. 

Carter J, Angel S, Lawrence-Snyder M et al (2005) Standoff detection of high explosive materials at 50 meters in ambient conditions using small Raman instrument. Appl Spectrosc 59 769-775 Ferreira EC, Milori D, Ferreira EJ et al (2011) Evaluation of laser induced breakdown spectroscopy for multielemental determination in soils under sewage sludge conditions. Talanta... 

The FOX is instrumented to detect chemical contamination in its immediate vicinity with a variety of probes, and at a distance via a standoff detector (M21). Meteorological data are also sensed. Data are analyzed, synthesized, and transmitted to higher-echelon units by a secure, jam-resistant communi-... 

Silver nanoparticles were also used to improve the detection of liquid solutions of analytes at a target-collector distance of 7 m. The experimental setup of the prototype instrument used to perform standoff Raman detection is schematically shown in Figure 8. The prototype system consists of an Andor Technologies Shamrock spectrograph equipped with a charge-coupled device detector (CCD), a reflecting telescope, a fiber optic bundle cable, a notch (or edge) filter assembly and a laser source (532 and 488 nm) for active standoff Raman detection. 

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