Abstract: The noise originating from the ambient radiation is derived from the measurement of the radiation of a source (S) via a preliminary correlation calculated between the measurements of the main detector (1) and of at least one auxiliary detector (2): when the radiating source (S) is present, the auxiliary detector (2), which keeps on measuring the ambient radiation, is used to evaluate the proportion of the main detector (1) measurement which comes from the ambient radiation. This invention applies to the measurement of the activity of various objects proving a low radiation level.

Abstract: A device and a method of remotely locating &agr; particle sources. In the method of remotely locating sources of &agr; particles in an environment, a scintillating gas is used that may contain nitrogen and fills the environment (10, 30), the scintillating gas is used to convert the &agr; particles emitted by the sources (14) into ultraviolet radiation, and an image of the ultraviolet radiation is formed on a photosensitive surface (20). This image can be displayed on film or on a video screen and may be superimposed on the visible image of the observed field. The device and method may be applicable to radioprotection and to the detection of the presence of radioactive materials and sources of radiation leaks.