JUELICH, GERMANY AND BEDFORD, ENGLAND Emisens and Microtek have introduced a liquid-identification system that could enable airport authorities to lift restrictions on passengers carrying bottles of liquid in their hand luggage. The system, which is known as EMILI 1+, uses a microwave-sensing technique to identify whether the contents of a bottle are harmless, inflammable, corrosive, or explosive. At the heart of the system is a multimode sensor, which emits an evanescent microwave field. That field penetrates the bottle under test and enables the dielectric permittivity and ionic conductivity of the liquid to be measured. From these parameters, the system can determine the type of liquid in the bottle and display the result. EMISENS is a spin-off company from the German Federal Research Centre, Forschungszentrum, Jlich.