To meet those needs, engineers at Ametek Advanced Measurement Technology, Paoli, Pa. (ametek.com),upgraded an earlier offering and now manufacture the Detective-Ex-100. It uses a larger, high-purity germanium-crystal detector for increased sensitivity and low-energy efficiency. This lets the device identify radioactive materials faster and without any loss of accuracy. The new machine takes half the time of the previous one to detect and identify lowenergy emitters (including highly enriched uranium), and about a third of the time to do the same for medium to high-energy emitters (including plutonium and other naturally occurring radioactive materials such as porcelain fixtures and kitty litter). The detector even finds radioactive materials shielded by heavy metals.

To make the device more portable and eliminate the need for liquid nitrogen, it carries an onboard cooling system. When fully powered, it will operate for up to 3 hr on internal batteries. For ease of use, it has touchscreen controls for transmitting data, memory stick storage, and can do analysis in the field.