Info Real gas - the real deal
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
goldfishtornado
Registered
Nice write up. Glad it's being preserved.
I wonder if the it's worth asking a mod if it should be stickied in the Resources Portal?
I wonder if the it's worth asking a mod if it should be stickied in the Resources Portal?
MadUKDiver
Registered
Thanks for reposting this again David. I used your excellent work in my MS Excel workbook YaGaMiC and have been happily blending accurately ever since 
Post edit at Akimbo's request to include a copy of the spreadsheet...
I wrote this in 2016 when I did not have access to J's of pure helium and was regularly blending two pre-mix trimix plus oxygen and air to try and achieve a desirable outcome mixture. No other software around at the time offered this in a single step.
Originally it used Ideal Gas and Van der Waals methods (including the Atomox error) and shortly after I added GERG 2004 based upon David's work. All three are displayed on the same sheet so you can easily compare results.
I wrote it for myself without any real intention to publish and MS Excel was an easy and familiar tool that allowed me to experiment with equations I didn't really understand. Hence it only supports the metric system. I did put it up on TDF and a number of people downloaded it at the time and some found it useful. Some other stuff got added based upon emerging needs or private requests.
To use it you will need to have the Excel "Solver" Add-In installed on your computer and to enable macros when the spreadsheet loads. It will automatically load the Solver if it is present so you don't have to faff around in Excel Options.
There are no instructions but basically type in the blue text and see what happens. It should be pretty self explanatory for anyone capable of blending.
One issue I am aware of is language localisation. Something in the coding balks when the local language is not 'English'. Sorry, I never got around to narrowing the cause and fixing it.
It can be freely distributed without any fees. Hopefully it goes without saying that use is at your own risk and there is no warranty as to accuracy or fitness for purpose. Happy to take feedback by DM and if you modify it for the better then please send me a copy (or post in in this thread).
Post edit at Akimbo's request to include a copy of the spreadsheet...
I wrote this in 2016 when I did not have access to J's of pure helium and was regularly blending two pre-mix trimix plus oxygen and air to try and achieve a desirable outcome mixture. No other software around at the time offered this in a single step.
Originally it used Ideal Gas and Van der Waals methods (including the Atomox error) and shortly after I added GERG 2004 based upon David's work. All three are displayed on the same sheet so you can easily compare results.
I wrote it for myself without any real intention to publish and MS Excel was an easy and familiar tool that allowed me to experiment with equations I didn't really understand. Hence it only supports the metric system. I did put it up on TDF and a number of people downloaded it at the time and some found it useful. Some other stuff got added based upon emerging needs or private requests.
To use it you will need to have the Excel "Solver" Add-In installed on your computer and to enable macros when the spreadsheet loads. It will automatically load the Solver if it is present so you don't have to faff around in Excel Options.
There are no instructions but basically type in the blue text and see what happens. It should be pretty self explanatory for anyone capable of blending.
One issue I am aware of is language localisation. Something in the coding balks when the local language is not 'English'. Sorry, I never got around to narrowing the cause and fixing it.
It can be freely distributed without any fees. Hopefully it goes without saying that use is at your own risk and there is no warranty as to accuracy or fitness for purpose. Happy to take feedback by DM and if you modify it for the better then please send me a copy (or post in in this thread).
A ScubaBoard Staff Message...
- Messages
- 17,334
- Reaction score
- 13,744
- # of dives
- 100 - 199
A mole is a small mammal who likes burrowing in the ground. Alternatively, a melatonin-rich small patch of skin, usually roughly circular (if it isn't, DO check in with your GP ASAP)
A mol is 6.022e23 molecules.
They are not the same (insert meme here)
What is 6.022e23 guacas? One guacamole
admikar
Contributor
Jglo27
Registered
Thank you for posting this! So helpful!
Mole is correct (although it also designates everything else you mentioned): Mole (unit) - Wikipedia
mol is the symbol for mole. Not sure who decided a four letter word needed to be abbreviated to three, but that's how it is
Have you compared the results of Gerg-2004 with the ones you are getting with your tweaked VDW model in this thread?
rmssetc
Contributor
As great as Scubaboard is.... I submit it's not a good place to act as a long-term repository for source code (witness the recent outage with loss of data, the fact that moderators can & do delete posts & threads, etc).
Please consider creating a Github (or gitlab, or sourceforge, etc) repository to share this valuable information where it can more easily be found by software developers and extended.
Similar threads
