PNNL device pinpoints suspicious liquids

Researchers at the Pacific Northwest National Laboratory have developed a monitor they say can detect suspicious liquids, using acoustic wave technology that measures density of substances.

The devices rely on acoustic ultrasound that tracks how fast or slow sound travels within a container. The technology was developed at PNNL several years ago and was first used in a product called the Acoustic Inspection Device, which was deployed by the U.S. Customs Service for use at borders.

A smaller version has been developed by the same PNNL researchers, prompting discussion that the technology could be used by federal Transportation Security Administration screeners. Some federal officials, following the recent discovery of an alleged plot to blow up planes using chemicals brought aboard disguised in liquids and gels, have said no simple method exists to screen such products carried by passengers.

Aaron Diaz, a PNNL researcher in Richland who helped develop the first acoustic device, disagreed, saying the newer system can solve the problem.

“We’re making these measurements (now) in about three to four seconds, but I think we could get it down to one or two,” Diaz recently told a Seattle newspaper.

The first model simply tracked the speed of waves moving back and forth in a container of liquid. Diaz said the newer version also tracks attenuation, the change in pattern the waves make.

Diaz was also quoted saying federal officials and the TSA only began showing interest in the new technology in the past two weeks.

After that story appeared in the Seattle Post-Intelligencer, federal officials contacted PNNL’s staff to remind them they were not free to discuss the technology without prior approval. As of Friday, the federal agency paying for the new and improved acoustic device has declined to allow additional discussion of the device, said PNNL spokeswoman Andrea Turner.

Turner said she could not identify the agency underwriting the development of the newer device.

The larger, initial device was designed originally to be used during the first Gulf War. In addition to funding from U.S. Customs, the Internal Revenue Service helped its development, according to Turner. The IRS has used about 10 commercial versions of the first acoustic device to track the quantity and quality of liquid fuels brought across borders by tanker trucks.

In addition to identifying nearly any liquid, the acoustic device can discern whether a container has concealed compartments. The PNNL press release on the device said: “It detects hidden compartments in solid forms such as metal ingots and tar kegs that may contain contraband (drugs or other smuggled commodities), or weapons of mass destruction.”