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Dear Jean,
Impressive as usual, but too steep for my understanding... as usual too!
Are all these water saturation/pressure/enthalpy calculations directly made by you from raw data?
I don't see any of the usual water pressure formulae (Tetens, etc.) in this sheet.

Wrote

Dear Jean,
Impressive as usual, but too steep for my understanding... as usual too!
Are all these water saturation/pressure/enthalpy calculations directly made by you from raw data?
I don't see any of the usual water pressure formulae (Tetens, etc.) in this sheet.

My Bible is mostly the 1958 M.P. WUKALOWITSCH water steam booklet
in 4 languages: French, English, German, Russian.
No significant disagreement wrt IAPWS-97,
all those properties are experimental with some uncertainties.
I also consult Katmar not freeware but can be used 5 min per session 0 $.
I got lot of stuff from Bernard Spang [ChemEng].
Most of the polynomials in this document agree with Lagrange criteria ± sign.
For an unknown reason the Grand Savants have ignored Thiele.
The attached SUPPLEMENT is simply gorgeous as bar saturation.
It borrows the data points from so called source and up to execute.
In a steam circuit, measuring the temperature from pressure is much
faster than via T/C [Thermo-Couple} and more accurate unless a high
quality Pt100 thermometer is used, very fragile and slow.
Thanks Collab for your appreciation ... Jean.

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... in your document, round 'K' 6 decimals.

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Wrote

Dear Jean,
Impressive as usual, but too steep for my understanding... as usual too!
Are all these water saturation/pressure/enthalpy calculations directly made by you from raw data?
I don't see any of the usual water pressure formulae (Tetens, etc.) in this sheet.

Ioha,
For you curiosity, I have added two Tetens segments [brute force] not to avail.
The Lagrange poly order 9 is lot more accurate as a single function.
Water is like air, their properties don't respond to single DE,
thus the need to best piece wise approximate.
Air between -1 km ... 100 km is in 3 pieces [NASA, OACI]
Cheers ... Jean

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Wrote

Dear Jean,
Impressive as usual, but too steep for my understanding... as usual too!
Are all these water saturation/pressure/enthalpy calculations directly made by you from raw data?
I don't see any of the usual water pressure formulae (Tetens, etc.) in this sheet.

The two documents refreshed/refactored.
1. most used ... Last Lagrange replaced by a normalized rational fraction.
2. ... SUPPLEMENT refactored to extends Tetens [180 °C, 10 bar]
Given both ways saturation [bar(°C), °C(bar)].
If you have more interest in Tetens, I may look to extend a bit more.
Please, let me know. Take care ... Jean.

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Wrote

If you have more interest in Tetens, I may look to extend a bit more.

This last brew certifies/solves Tetens [85.9 bar ... 300 °C].
Enjoy ... Jean

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Dear Jean, I am only architect and I used Tetens' formula just to find the absolute humidity from the relative humidity from data collected from my data loggers... Your calculations are far too accurate for my needs!
However I will share my attempts at dome calculations based on Maxwell's polar polyedra and Marina Konstantatou's thesis (I have seen impressive visuals here based on just the in-built 2D and 3D graph regions)... for which you could maybe help me!
Thank you,
Laurent

Wrote

Dear Jean, I am only architect and I used Tetens' formula just to find the absolute humidity from the relative humidity from data collected from my data loggers... Your calculations are far too accurate for my needs!
However I will share my attempts at dome calculations based on Maxwell's polar polyhedra and Marina Konstantatou's thesis (I have seen impressive visuals here based on just the in-built 2D and 3D graph regions)... for which you could maybe help me!
Thank you,
Laurent

Laurent, please attach some data [vectors, table ...].
I can't resit data ... smoothing, fitting, surface plot, rotation.
Your stuff will delight Smath Community and we all go along so well !
Wait and see from so far away ... Jean

Wrote

Dear Jean,
Impressive as usual, but too steep for my understanding... as usual too!
Are all these water saturation/pressure/enthalpy calculations directly made by you from raw data?
I don't see any of the usual water pressure formulae (Tetens, etc.) in this sheet.

Updated my Water Vapor Saturation file. It's per ASHRAE IP units

... last segment in pink [255, 225, 225] pushes Tetens up to 370 °C ± 0.5 bar.

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