B NIST database and compressibility factor Z

AI Thread Summary
The NIST database offers extensive data on various fluids, including Nitrogen, across a wide range of pressures and temperatures. However, there are concerns regarding the accuracy of the compressibility factor data, as it may not align with established charts like Standing and Katz's. Users are questioning whether the NIST data is based on approximations or calculated using specific formulas. The original poster later found the reference articles that clarify the data sources. This highlights the importance of verifying data accuracy when using large databases for experimental research.
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Is NIST database accurate?
There's a huge volume of data on NIST database:
https://webbook.nist.gov/cgi/fluid....nit=m/s&VisUnit=uPa*s&STUnit=N/m&RefState=DEF

I'm interested in getting extensive sets of experimental data for the compressibility factor of Nitrogen. Could not find them anywhere until now, so it seems strange to me that NIST has a huge database for all ranges of pressures and temperatures. Do any of you know if the data on NIST database are approximations calculated with some formulae? For example, the NIST data do not seem to represent the Standing and Katz's chart accurately. Thanks.
 
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My bad, I finally found the reference articles for the database. Sorry.
 

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