|NUKLEONIKA 2012, 57(4):633-635
LABORATORY AUTOMATIC MEASURING SYSTEM FOR GAMMA SPECIMENS
Adrian Jakowiuk, Paweł Filipiak, Jakub Bartak, Paweł Pieńkos, Ewa Kowalska
Institute of Nuclear Chemistry and Technology, 16 Dorodna Str., 03-195 Warsaw, Poland
LG Gamma Counter is designed for low activity measurement of the radioactive isotope iodine 125I in liquid or solid samples during radioimmunoassay (RIA) and immunoradiometric assay (IRMA) in small or medium size clinic laboratories. Apart from RIA and IRMA programmed procedures, a measurement of small activity gamma samples is possible. The well scintillator NaI(Tl) is used as radiation detector for the isotope 125I in the measuring channel, the well dimensions PHI being 17 × 38 mm. Gamma Counter was adapted for measuring radioactivity of single samples. The counter is equipped with an automatic system allowing transportation of examined samples to a scintillator well. The gauge is based on an integrated computer which is working under the control of Windows CE and is equipped with special software allowing for setting measurement parameters and communication with an external computer. The measured sample is placed inside the scintillator well either by an automatic sample feeder or manually. The pulses from a photomultiplier tube after amplification and shaping in pulse amplifiers are counted in the window of a single channel analyser by a programmable pulse counter under the control of microprocessor system. The measured count rate is the measure of activity of the assayed sample. Expected count rate error due to unstable operation of amplification is lower than 1%.