  In the early 1990's A. Elitzur and L. Vaidman proposed an interaction free
measurement (IFM) that allows researchers to find infinitely fragile objects
without destroying them. But Elitzur-Vaidman IFM has been used only to
determine the position of opaque objects. In this paper, we propose an
extension of such a technique that allows measurement of classical electric and
magnetic fields. Our main goal is to offer a framework for future
investigations about the role of the measurement processes, expanding the
physical properties that are measurable by means of IFM.
