Estimation of Measurement Uncertainty for 230Th Radioisotope Analysis in Soil

The uncertainty of a measurement is the interval of values within which the true value is believed to lie with a stated probability when all sources of error have been taken into account and is therefore represents the reliability of a measurement. In this study, we evaluate the measurement uncertainty in the determination of 230 Th in the soil sample using a radiochemical separation procedure and alpha spectrometry. All the sources in the analysis method that contribute to the combined uncertainty were identified. The uncertainty associated with a certain parameter was used to determine its partial contribution to the combined standard uncertainty of the measurand. The spreadsheet and full matematical approach was used to present the combined standard uncertainty.