Abstract: A carrier for at least on beta-particle-emitting sample to be measured in a scintillation counter comprises a sorption sheet on which the sample is to be deposited, a transparent bag within which the sorption sheet with the sample is to be contained, and a scintillant to be contacted with the sample within said bag. According to the invention the scintillant is a meltable solid scintillant which is coated onto at least part of the sorption sheet and/or the inside of the transparent bag, and which is to be melted to envelop and permeate the sample before measurement thereof.

Abstract: In a sorption sheet (1) for sorbing a plurality of discrete samples that simultaneously emit photons or beta particles, the emission thereof to be individually monitored, barriers (2) of a photon and/or beta particle attenuating material extend through at least a portion of the thickness of the sheet (1) which is known per se, to prevent cross-talk between the samples when monitored. The barriers are produced by soaking a liquid photon and/or beta particle attenuating material in a pattern of lines through at least a portion of the thickness of the sheet, whereupon that material is dried and/or cured.

Abstract: The radioactivity of discrete areas of radioactive material on a surface region of a support layer is monitored by converting the radioactivity emitted by these areas into light emissions with the use of a suitable scintillant, and scanning the surface region with at least one photodetector in a plurality of discontinuous steps. Each step places the support layer and the or each photodetector in relative positions in which the or each photodetector detects at least a proportion of the light emissions activated by a respective one of the areas of radioactive material over a finite interval of time. A plurality of output signals are therefore produced by the photodetector(s), each of which is proportional to the radioactivity of a respective one of the areas of radioactive material.