This statistic uses the sign test to determine the number of samples needed by evaluating whether the median of the data is above or below the DCGLW. This test is used when contamination is not present in the background and measurements are radionuclide-specific or if background levels are a small fraction of the DCGL.
Select Sign Test from the Statistics menu -> Number of Samples. SADA asks the user for a decision criteria, depending on the analysis type. Then, SADA presents the following window.
Compare contaminant levels with the DCGL levels. Each measurement below the DCGL contributes evidence that the survey unit is clean and the null hypothesis should be rejected.