Featured Product
This Week in Quality Digest Live
Metrology Features
Tracking changes in fluorescence from ultracold atoms is a super-sensitive indicator of pressure
Prashant Kapadia
Aid root cause analysis by detecting wear and tear in advance
Mike John
How metrology can bring the medical-device design and manufacturing process together
Steven Brown
21st-century standard candles at NIST

More Features

Metrology News
For light-duty industrial weighing applications
Precision manufacturers can monitor Universal Robots in real time and over time
New technology will allow customers to grow capacity, improve profit margins and gain efficiencies
Demonstrating a commitment to keeping people safe and organizations running
Meet the latest generation of LC xx6 encoders
On-demand pipe flow measurement, no process interruptions
Q-Span Gauging Systems improve efficiency, capacity, and real-time reporting of quality departments

More News



Better Cargo Inspection Standards at Border Crossings

NIST study provides feedback on two image-quality standards

Published: Wednesday, December 17, 2014 - 16:00

(NIST: Gaithersburg, MD) -- As part of an interagency agreement between NIST and the Department of Homeland Security (DHS), PML’s Radiation Physics Division recently completed a series of image quality measurements of a high-energy X-ray vehicle-screening system at a newly constructed port of entry near El Paso, Texas.

In their study, researchers compared the performance of two image quality standards, ANSI N42.26 and IEC 62523, for cargo and vehicle screening systems. These standards are recommendations by the American National Standards Institute (ANSI) and the International Electrotechnical Commission (IEC). The purpose of the work was to provide feedback on the practical use of the two standards and recommend possible improvements, with a goal towards harmonization.

Key findings from the image quality tests were summarized in an interagency report to the DHS. Recommendations included a design change to objects used in the IEC test, the addition of a material discrimination test method for the ANSI standard, and a provision to include blind testing to improve the objectivity in both standards.

The four step wedges used as test objects in the study.

An X-ray image showing a standard test object (upper left) held aloft by support apparatus and a forklift. In this case, the test object is a wedge of steel with steps of various thicknesses. Although NIST’s intention in this study was to evaluate the test objects and not to inspect vehicles, the X-ray of the forklift gives a viewer a sense of the system’s imaging capabilities. Note the circular object at right, the gas tank, which is half full.


About The Author

NIST’s picture


Founded in 1901, the National Institute of Standards and Technology (NIST) is a nonregulatory federal agency within the U.S. Department of Commerce. Headquartered in Gaithersburg, Maryland, NIST’s mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.