The three properties that you enter for the Reference Fluid are "passed through" the element and become outputs which you can then link to other elements.
You can save these results by clicking Final Values and/or Time Histories. Checking one of these causes all three outputs to be saved as results. If you wish to save only one or two of these as results, you can use the context menu of the output (accessed via a right-click) in the browser to turn on or off one or more of the three outputs. In this case, the checkbox in the dialog would become gray (indicating that some of the results will be saved).
The display units for these three outputs are specified immediately to the right of the inputs (the Relative Diffusivities are dimensionless, and hence have no display units).
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