"Uptake rate standard deviation of ammonium {NH4+ CAS 14798-03-9} per day per unit volume of the water body [particulate >GF/F phase] by isotope-labelled tracer addition, incubation at unspecified light level, filtration and mass spectrometry on residue"@en . . "SDN:P01::AMSDIIP1" . "The square root of the average of the squares of deviations about the mean of a set of values of the specified measurement."@en . .