Explosives Detection Through Opaque Containers with Agilent Resolve - a Handheld SORS System

Importance of the Topic

The ability to identify hazardous materials without opening containers is critical for security screening, customs inspections, and forensic investigations. Handheld systems that can noninvasively detect and distinguish explosives behind opaque barriers help reduce risk to personnel and speed up field operations.

Objectives and Study Overview

This application note demonstrates how the Agilent Resolve handheld Raman system, employing spatially offset Raman spectroscopy (SORS), can rapidly differentiate benign palm oil from a wide range of homemade, commercial, and military explosives. Measurements are performed through colored or opaque plastic containers in under one minute, without compromising sample integrity.

Methodology and Instrumentation

The operator selects a through‐barrier measurement mode on the Resolve system. The user sets barrier type (thick, colored, opaque) and may apply a scan delay or laser power reduction for sensitive samples. Typical scan times are automatically adjusted to yield optimal Raman signal quality, averaging about 60 seconds per scan. Test samples included full‐size plastic containers filled with palm oil or explosive material, and smaller explosive packs taped inside larger containers. Primary explosive testing was conducted under controlled conditions with expert support.

Key Findings and Discussion

• All concealed materials produced high‐quality Raman spectra matching library references despite barrier interference.
• Explosives tested included TNT, Semtex H and A, TATB, PETN‐ and ammonium nitrate‐based formulations, TATP, HMTD, and precursor mixtures.
• Library search results highlight priority matches in red and other acceptable matches in green, facilitating rapid decision making.
• Scan times remained around one minute, demonstrating practical throughput for field operations.

Benefits and Practical Applications

The Resolve handheld SORS system offers:

• Noninvasive screening through opaque or colored plastic, glass, paper, and fabric.
• Rapid identification without container breach, enhancing operator safety.
• User‐friendly interface with priority tagging and clear result display.
• Field deployability for security checkpoints, military operations, and emergency response.

Future Trends and Opportunities

Advances may include expanded spectral libraries for new threats, integration of machine learning for automated result interpretation, miniaturization for increased portability, and adaptation to additional barrier materials such as metalized films and multilayer composites.

Conclusion

Agilent’s handheld Resolve SORS system effectively identifies explosive and benign materials through opaque barriers in under one minute. The technique delivers reliable, high‐quality Raman spectra without container penetration, supporting rapid and safe field analysis.

References

• Stokes R, Presly O. Application Note 5991-8868EN. Agilent Technologies, Inc.; 2018.