Column Name: CSU
Description: The Combined Standard Uncertainty (CSU) is the estimated standard deviation of the result. The CSU can be used to estimate the "confidence interval" around the amount. Thus, if y is the "best estimate" of measured radioactivity, the 95% confidence interval around y ranges from about y-(2xCSU) to y+(2xCSU). For Strontium-90 in milk during the period of 1960 through July 1978, the uncertainties were +/- 2 pCi/L (two sigma) for Sr-90 concentrations less than 20 pCi/L, and 10% of the concentration for Sr-90 concentrations greater than 20 pCi/L. Sample specific uncertainties are available for data beginning in October 1975 (two sigma).
Envirofacts Table Name(s):
Definition Source:National Air and Radiation Environmental Laboratory (NAREL)