New Technology Being Developed To Detect Land Mines And Other TNT Ordnance

New technology being developed at Mississippi State University is designed to help detect land mines and other ordnance containing a crystalline, water- insoluble high explosive called trinitrotoluene, known to all as TNT.

Funded by the U.S. Army Research Office, the project also involves the U.S. Army Corps of Engineers' Waterways Experiment Station in Vicksburg. The product of their labors will be a highly sensitive instrument system that improves the ability to locate the long-buried antipersonnel weapons.

Research with sensors and the development of an instrument capable of finding trace TNT quantities in soil is the responsibility of Mississippi State's Diagnostic Instrumentation and Analysis Laboratory. Corps of Engineers scientists are providing expertise in soil sampling.

"The land mine problem is a deadly legacy of 20th century wars," said DIAL director John Plodinec. "Particularly in the north of France, it is all too common for farmers or their families to be maimed or killed in apparently peaceful hay fields by mines left behind from the world wars."

According to international estimates, more than 115 million land mines lie buried on 20th century battlefields. On average, they kill or maim a person every 22 minutes. There also are countless pieces of other unexploded ordnance- -bombs and other weapons--on battlefields and weapons testing ranges. Many contain TNT.

Waterways Experiment Station researchers have developed a cone penetrometer that can probe the soil in areas where the presence of TNT is suspected.

DIAL scientists, under the leadership of Jagdish Singh, are developing a sensor to identify concentrations of TNT and similar substances, which collectively are known as toxic energetic materials or EMs.

Singh said current detection methods require collecting soil samples and sending them to a laboratory for analysis. "The cone penetrometer can be used at suspected contamination sites once an EM sensor is developed," he explained.

For their part, DIAL scientists have successfully tested a laser-based optical sensor to detect small amounts of TNT in soil--an important step in the overall project.

Because TNT and EMs penetrate into the soil and eventually enter the ground water, detection of soil containing the substances also can be valuable in cleanup efforts at American and other defense installations.

"It is difficult to clean contaminated water when it migrates into groundwater," Singh said. That is why it is important to locate and remove contaminated soil before this happens."

Plodinec and Singh collectively expressed hope that the "deadly legacy" of this century's conflicts will pose less of a threat to future generations once Mississippi State and Waterways Experiment Station scientists complete their work.