Absolutely the weather correction is key. But correcting simply for density will get you 97% there. Yes, there are small differences. But there should not ever be large differences if both flowbenches are quality pieces, calibrated and properly operated. Of course you will see small variations... But a while ago, there was a dicussion that so and so's flowbench reads 275 CFM, while some other guy's reads 250 Cfm, both at 28"... THat is just plain garbage data there... One of them (or both, with one higg and one low) is clearly WAY off.......
And Yes, NASA, Boeing, Airbus, and any steam turbine/gas turbine manfuacturer gets it, and does it right, thats for sure.
And regardless of the density, the square law is... well a LAW

(sorry, had to get that in one last time

)
Good conversation, gents.
PS: Adger, I have the same sort of books on my nightsand too... My wife thinks Im nuts... She says "nothing like a little "light" reading before bed, huh hon ?? " ....
Kevin