Abstract: A method of obtaining information about radiation arising from within an environment includes providing a directionally sensitive radiation detector which has a field of view and providing a visual image capturing device which has an area of vision. The radiation for a field of view is measured, the field of view including a part of the environment. The measurement of radiation is recorded together with an indication of the space or position of the respective field of view relative to the detector. A visual image of an area of vision is obtained, the area of vision including the part of the environment within the field of view. The image is recorded together with an indication of the spatial position of that field of view relative to the detector. Selecting the set of data from the measurement of radiation according to a criteria set after completion of the measurements of radiation. The information is overlaid from one or more of the measurements of radiation with one of the visual images.

Abstract: A method of investigating the response of an instrument to gamma emissions using a source package includes providing a source package on one side of a collimator including an aperture and a detector on the other side of the collimator relative to the source package, the collimator and detector positions defining an operating axis for the instrument. The position of the source package is then moved relative to the collimator. The response of the detector is measured for two or more of these different positions of the source package. The aperture in the collimator has a first dimension measured in a first direction perpendicular to the operating axis. The source package includes one or more individual gamma emitting sources provided in a container. During use, the individual source(s) have an overall extent in the first direction, the overall extent, during at least 10 seconds of use, being two or more times the first dimension of the collimator in that first direction.

Abstract: A method of investigating the response of an instrument to gamma emissions using a source package includes providing a source package on one side of a collimator including an aperture and a detector on the other side of the collimator relative to the source package, the collimator and detector positions defining an operating axis for the instrument. The position of the source package is then moved relative to the collimator. The response of the detector is measured for two or more of these different positions of the source package. The aperture in the collimator has a first dimension measured in a first direction perpendicular to the operating axis. The source package includes one or more individual gamma emitting sources provided in a container. During use, the individual source(s) have an overall extent in the first direction, the overall extent, during at least 10 seconds of use, being two or more times the first dimension of the collimator in that first direction.