Lab Scout - Gamma Quantifier with Integrated Scale - Manual

SARAD GmbH Manual BioScout 1 Manual_BioScout_EN_20-12-12.docx © SARAD GmbH Manual BioScout December 2012 SARAD GmbH Tel.: ++49 (0)351 / 6580712 Wiesbadener Straße 10 FAX: ++49 (0)351 / 6580718 D-01159 Dresden e-mail: support@sarad.de GERMANY Internet: www.sarad.de BioScout The Bio-Scout allows the fast and reliable detection of radioactivity in food. A large volume (2”x2”) NaI detector (used in Marinelli-geometry) in combination with a Gamma spectroscope gives the possibility to detect six pre-defined nuclides like Cesium or Iodine. The results are presented in Bq/kg by measurement of the sample weight using the internal scale. Detector Scale plate Button Start/Toggle Signal lamps USB interface Power connector Display SARAD GmbH Manual BioScout 2 Manual_BioScout_EN_20-12-12.docx © SARAD GmbH Finding the right place for the instrument In order to minimize the required sample time, the instrument should be placed at locations with low background radiation. Increased background (>100nSv/h) can appear in buildings with walls/floors made from natural stones (Granite, Marble etc.) or inside rooms with high Radon concentrations. If the unit shall be used in radiological laboratories, other radioactive sources must not be stored close to the Bio-Scout. Setting the Bio-Scout in operation Before connecting the power adapter, an empty sample container (Marinelli beaker) must be placed at the sampling desk. This is required for the zero-calibration of the internal scale. As soon as the power is present, all three lamps will light for a short time and the buzzer gives an acoustic signal. A ten minutes measurement starts automatically to determine the local radiation background. If the instrument has been relocated, this procedure must be repeated (disconnect/connect power adapter). The display shows the remaining time for background measurement. After that appears “Press START for first sample”. Filling the sample into the beaker It is strictly required to fill the food sample correctly into the Marinelli beaker. The beaker must be always filled completely with 1 liter sample volume. This volume gives the reference fort the density calculation at the one hand and ensures a correct sampling geometry at the other hand. If sampling beakers with geometries different from the original shall be used, a re-calibration of the unit is required. Carrying out a measurement The analysis can be started by pressing the button below the display. Do not touch sample beaker or sampling desk to guarantee a correct result of the scale. If the net weight is smaller than 300g, an error message appears on the display. In this case, the system assumes that no or a not correctly filled beaker has been placed at the desk. The display shows after weighing the sample net weight as well as the required sample time to achieve the detection limits. For a 1kg sample and a background less than 100nSv/h, a sample interval of approximately 60 seconds is expectable. Higher background or less weight results in longer intervals. If after this period some significant activity has been detected, the analysis will be continued automatically for the same period to decrease the statistical fluctuations. The end of each measurement is indicated by an acoustic signal and lighting up of one of the lamps. Green lamp and short signal No activity in the range of the adjusted limits has been detected. The display shows “BELOW LIMIT Press START for next sample”. Red lamp and interrupted signal An activity above the limit has been detected at least for one of the nuclides. A list of detected nuclides appears on the display. Push the button to toggle the display to show the results for each nuclide. The button must be pressed for a longer period (until second beep) to go back to the measurement mode. To show the results again, press button on time long and one time short. SARAD GmbH Manual BioScout 3 Manual_BioScout_EN_20-12-12.docx © SARAD GmbH A unique ID number will be assigned to the spectrum which will be stored in the internal memory for later readout. Yellow lamp and interrupted signal An activity above 50% of the alert limit has been detected at least for one of the nuclides. The display function is the same like for red indicator. It is recommended to repeat the measurement. Predefined nuclides, detection limits and alert limits In case of nuclear accidence, a number of nuclides is used as tracers such as I-131, Sr-90, Pu-239 und Cs-134/137. Additionally, large amounts of Te-132 and Ru-103/106 were emitted after reactor crash. Because of their half life times and mobility, especially Cesium, Strontium and Plutonium are of interest for food samples. Strontium and Plutonium are not or very difficult to detect by gamma spectroscopy while Cesium is good detectable even with NaI detectors. The following table shows the list of the six selected nuclides detected by the Bio-Scout. Nuclide Detection limit [Bq/kg] Alert limit Bq[kg] I-131 100 200 Cs-137 100 100 Cs-134 100 100 Ru-103 100 - Te-132 100 - K-40 100 200 The analysis procedure presumes that the sample does not contain any activity from natural occurring nuclides except K-40 (Potassium). This is the case for any food sample. The Bio-Scout is not suitable to measure soil or material samples containing elements of the Uranium or Thorium decay chain. In this case, the activities are interpreted as an increase of the natural background leading to a new background measurement. Many foods contain Potassium so that the unit tolerates K-40 up to a level of 200 Bq/kg. USB interface The acquired gamma spectrum of a sample will be stored in case of alert (up to 70 spectra). The USB interface allows the download of the spectra for further assessment. Furthermore, all settings with regarding the nuclide definition and analysis parameters are done via this interface. The receptacle is placed on the bottom of the control panel (left side).