- The software package "WaterSteamPro" recommended by Department of General Inspection for Exploitation of Electrical Power Stations and Networks of Russian Joint Stock Company Unified Energy System of Russia (RAO "UES of Russia" - http://www.rao-ees.ru/en/) for usage in energetics (information letter # IP-14-27-2001 from 03.08.2001).
- Significantly improved the speed of calculation. Approximate calcultation speed increasing given here.
- Added 8 new functions for complexing properties calculation. It's significally decrease the time of calculation when you need more then one property at one point. In addtition, new functions allow to calculate pressure and temperature derivates of main properties. List of new functions given here.
- Added new function wspDPDTST for calculating derivative of saturation pressure on saturation temperature.
- Signfically revision of calculating properties in double-phase region:
- Added 2 new functions for calculating isochoric heat capacity (Cv) at saturation line from the double-phase region area. These functions allow rightly calculate (from the point of view of thermodynamic) next propeties in double-phase area: isochoric heat capacity, isoentropic exponent, sound velocity. List of new functions given here.
- Function wspCVSTX now used functions, mentioned above, which consider isochoric heat capacity jump at saturation line. It's allow to remove this function from "non thermodynamic" category.
- Function wspKSTX now used functions, mentioned above, which consider isochoric heat capacity jump at saturation line. It's allow to remove this function from "non thermodynamic" category.
- Function wspWSTX now used functions, mentioned above, which consider isochoric heat capacity jump at saturation line. It's allow to remove this function from "non thermodynamic" category.
- Function for calculating Joule-Thompson coefficient in double-phase area (wspJOULETHOMPSONSTX) now calculate the value, proper from the point of view of thermodynamic: JT = (dt/dp)h=const, but not from degree of dryness (as in previous versions). It's allow to remove this function from "non thermodynamic" category.
- Search is added in documentation .

- In April 16 2001 the program "WaterSteamPro" was received the official certificate from GOSSTANDART OF RUSSIA (http://www.gost.ru). The registration number is "AK-35/4". The electronic copy of certificate situated in the www-site of the WaterSteamPro: http://twt.mpei.ac.ru/orlov/watersteampro/eng/certif.htm.

This certificate describes that WaterSteamPro functions reproduce the values from the standart reference data (GSSSD R-776-98) and the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. - Added 13 new functions for calculating meta-stable area of steam. List of the new functions given here.
- New functions supported in program WSP Calculator.
- Some improvements to internal code of functions. Speed of calculation now increased.
- Big changes in Mathcad Samples. They are now more small and have new look.
- All new samples for Mathcad are now renamed to 8.3 format and now installed to subfolder "WaterSteamPro" of your "My Documents" folder.
- Big changes in programming code for registration. Now it's more small and fastest. All registered users may use his own regisration code as usually.
- Mathcad file "units.mcd" with additional dimensions for the WaterSteamPro are now renamed to "wspunits.mcd" for unification with russian version of the WaterSteamPro and for compability with another users files. Old file "units.mcd" included only for compability.
- Changed registration form.
- Documentation changed.

- In April 16 2001 the program "WaterSteamPro" was received the official certificate from GOSSTANDART OF RUSSIA (http://www.gost.ru). The registration number is "AK-35/4". The electronic copy of certificate situated in the www-site of the WaterSteamPro: http://twt.mpei.ac.ru/orlov/watersteampro/eng/certif.htm.

This certificate describes that WaterSteamPro functions reproduce the values from the standart reference data (GSSSD R-776-98) and the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. - Added 16 new functions for calculating processed of expansion/compression. List of the new functions given here.
- With new functions WaterSteamPro have full support for calculating processes of expansion and compression.
- Added three new samples of the usage WaterSteamPro in Mathcad: sample os usage functions for expansion/compression. Search these files in your "My Documents" folder.
- Some improvements to program WSP Calculator.
- Some improvements in registration.

- Added 14 new functions for calculating processed of the expansion/compression. List of the new functions given here.
- Changed the registration rules, the details see in section F.A.Q..
- Changed file "watersteampro.mcd" for work with beta-version of the Mathcad 2001.
- Changed registration form.

- Added 59 new functions, listed in new file of the documentation functions history.
- There are functions with arguments (p, h) and (p, s) in new functions.
- There are functions for Joule-Thompson coefficient in new functions.
- Added function for checking internal version of the WaterSteamPro: "wspGETWSPVERSION".
- Rewritten program "WaterSteamPro Calculator" with new improvements.
- Fixed some bugs in samples file of the WaterSteamPro for Mathcad and added the examples of new functions to the WaterSteamPro Mathcad files (see graphics).
- Rewritten WaterSteamPro Add-in for Microsoft Excel. Now in "Insert function" Wizard displayed the quick reference for selected WaterSteamPro function.
- Added example of the usage WaterSteamPro in Borland Delphi.
- Added new section (some files) for developer. In current version it's files for usage WaterSteamPro in Delphi and Visual Basic.
- Fixed some cosmetic bugs in Excel examples.
- Fixed some cosmetic bugs in installation program.
- Documentation changed.
- Added new section "FAQ".
- Fixed bug in WSP Calculator: uncorrect value for the Surface tension with dimension equal to mN/m (value more right value for 10 ones). If dimension equal to N/m the value was right.
- Small bug in library OKAWSP5.DLL is fixed: earlier the function wspGETLASTERROR might return the value 0 (no error) when the some floating-point error occured in any function (the functions always return value "-1" - indicator of error). It's may be occured when the arguments value checking is disabled with the function wspSETCHECKRANGEMODE.
- New section "Special thanks" appeared in documentation.

- Added function wspGETLASTERRORDESCRIPTION(), which return the description of the error.
- Rewritten program "WaterSteamPro Calculator" with new improvements.
- Fixed bug in function wspXSTH(t, h). Earlier this function work only when the range checking is disabled.
- Changes in Microsoft Excel add-in OKAWSP5.XLA installation folder, which now install to Excel folder.
- Rewritten installation program.
- Documentation changed.

- All functions are transferred into C++ language and are arranged into a dynamic-link library (DLL).
- Calculations in the Mathcad environment are on the average order of magnitude quicker (at 8 - 14 times) as compared to the previous versions.
- The "WaterSteamPro" package is now executable in other program environments.
- The program "WaterSteamPro Calculator" is now available along with the sources in the Microsoft Windows environment allowing calculation of water and water steam properties.
- Examples of "WaterSteamPro" operation in Microsoft Visual Basic, Microsoft Excel, and even Windows Scripting Host are also available.
- The package is supplemented with new functions for calculation of water and water steam properties (see "List of functions for calculation of water and water steam properties").
- All functions have new names for reasons of unification (the version is not compatible with "WaterSteamPro" versions lower than 5.0).
- The installer is now available.