Stress testing metal detectors and other devices

In a large chamber at the Food and Drug Administration labs here, scientists are bombarding medical devices such as pacemakers and hearing aids with electromagnetic waves. Their goal: to see how safely the critical medical devices can interact with the growing volume of waves people encounter daily from increased use of electronic gadgets like microwaves, airport scanners and cellphones. The so-called anechoic chamber, which measures nearly 36-feet long, is made of special material that absorbs electromagnetic waves. It's considered to be the purest way to measure interactions between medical devices and electronic gadgets because there are no echoes or reflections of electromagnetic waves from the chamber's walls or ceiling to affect the calibrations.