The square root of the average of the squares of deviations about the mean of a set of values of the specified measurement.
DissPo210_SD_water<0.4/0.45um
Activity standard deviation of polonium-210 {210Po CAS 13981-52-7} per unit volume of the water body [dissolved plus reactive particulate <0.4/0.45um phase] by filtration, acidification and alpha spectroscopy