*Residence Time Distribution Curves*

*For **plug flow** the input and output are identical. For **mixed flow** the step input is transformed to exponentially growing F curve. For a pulse input into an exponentially decreasing C-curve. The arbitrary flow, to which a majority of flow system conform, the slope of the F curve (**D**) and symmetry the C curve (**E**) will increase with the number of mixing stages through which the sample plug has passed. The standard deviation of these curves equals axial dispersion and the time span between the input and the mean of the output curve is mean residence time. The F-curve is an integral of c curve:*