Abstract: UV sensing apparatus comprises a substantially light-proof housing (1), an aperture (1a) formed in the housing, a filter (2) positioned within the housing at the internal mouth of the aperture, a fluorescent member (3) positioned within the housing on that side of the filter remote from that adjacent to the aperture, and a light sensor (4) positioned within the housing to receive light emitted by the fluorescent member. The filter (2) is such that it substantially removes visible light, the fluorescent member (3) is such as to fluoresce when subjected to UV radiation, and the light sensor (4) is positioned so that substantially none of any electromagnetic radiation entering the housing (1) via the aperture (1a) impinges upon the light sensor.

Abstract: A method of acquiring an ionizing radiation image including, irradiating a material with patterned ionizing radiation, exciting the irradiated material with excitation radiation to emit light in accordance with the pattern and acquiring the emitted light. The excitation radiation has a wave length which does not cause substantial electron-hole recombinations in said material. Preferably, the irradiation forms luminescent centers in the material and the excitation radiation has a wave length suited for excitation of the luminescent centers.