RADIOACTIVE AREAL DENSITY DETECTOR WITH SCINTILLATING RECEIVER

摘要

Apparatus for continuously determining the areal density along a length of a material includes a radioactive source and a scintillating receiver. In a first embodiment, the invention measures the thickness of a traveling web simultaneously at multiple points across its full width. The apparatus includes a radioactive source (3) which extends across one side of the web (5). A detector array (6), on the opposite side of the web, detects the emission from the source through the web. The array includes scintillating fibers and multi- or single-anode photomultipliers (9) which may be connected by a scintillating or non-scintillating fiber optic elements (7) to the photomultiplier. In a second embodiment, the invention continuously detects the fill level of a plurality of containers as they are conveyed between the receiver and detector. A scintillating fiber receiver may have its fibers arranged either vertically or horizontally. When arranged horizontally, the fibers may be grouped and conduct photons to single anodes of a multi-anode photo-multiplier tube to provide direct physical measurement of the fill level. Still another receiver includes a plastic scintillator sheet directly coupled to a photomultiplier tube.