Why Are Liquid Properties in Steam Tables Labeled with an 'f' Subscript?

AI Thread Summary
Steam tables label liquid properties with an "f" subscript to denote the fluid phase, while gas properties use a "g" subscript. The choice of "f" is a convention in thermodynamics, although it can lead to confusion, especially since "l" could be misinterpreted as the numeral one. Some participants find the "f" designation less intuitive and suggest that font choice could mitigate clarity issues. The discussion highlights the importance of standardization in scientific notation to avoid ambiguity. Overall, the use of "f" for liquid properties is a recognized practice in thermodynamic data presentation.
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I'm curious as to why steam tables typically present liquid properties with an "f" subscript, such as ρf.The gas properties use a "g" subscript, so I would expect the liquid properties to use "l". My first guess at the meaning of the "f" would be that it means "fluid", but this wouldn't make sense since both liquids and gases are subcategories of fluids. Am I missing something obvious?

Some examples:
http://www.spiraxsarco.com/us/resources/steam-tables/sub-saturated-water.asp
http://www.efunda.com/materials/water/steamtable_sat.cfm
ASME steam tables are also presented this way but I can't find any free examples online.
 
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'l' can be mistaken for a number of different things, like the numeral one for example. 'f' means fluid, specifically the properties of the substance in the liquid phase. Think of it as a special convention for presenting thermodynamic data.
 
Thanks for the reply. I admit the 'l' isn't terribly clear in this font, but a little forthought in font choice could prevent the ambiguity. Personally, I find the 'f' more confusing, but maybe that's just me. It seems just as silly to use an 'm' subscript for the liquid phase since liquids are composed of matter.
 
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