CO2 Volume Chart-Extended...
Does anyone have a CO2 volume chart (pressure and temp) that goes colder than 30degrees F and higher pressure than 15psi?
To go much beyond the current limits of the Zahm type (ASBC) charts out there you will need to use some algorithms. They are provided in the Main ASBC methods manual (but really only for 20 C) but the better fuller ones were published many years ago in the Wallerstein publications. It may take me some time to get at them but I can try and find that Wallerstein article if really neeed.
I am also unsure as your comment about above 15 psi though.
This one goes down to 30, and up well past 15psi. It's isn't pretty on my screen though - hopefully yours looks better.
Just what the brewer ordered!
For temps below 30, try heating the Zahm shaker gently under warm water (not hot!) for a few seconds, shake and read again.
The temp/dissolved CO2/pressure relationship is linear so by gently heating, you can still get an accurate reading.
I have also found this trick handy when doing nitro's with a low target CO2 range (1.2-2.1 vol, depending on style).
I think the best table I've seen is the one in the "Brewer's Handbook". I know it goes above 15psi (my BBT don't), but not sure if it goes below 30F.
Here's a link to an Excel sheet I made. It doesn't go down that low, but you can easily extend it so it does. It uses various different temp/press units also. YMMV.