Interesting...... Just went to the Airgas website and they have a whole slew of C02 grades - including of course Food Grade for beverage dispensing and Industrial for welding. Check out the various grades under Specialty Gases - Sheesh!!!!
http://www.airgas.com/category/Gases/_/N-82b?Nrpp=15
RTD's are faster and more accurate - cost more too (go figure). TC's are cheap but are fine for fridge. I would use a RTD for Mash and HLT.
NOW get brewing son!
The jumper should be across 9 and 8 and only for a RTD. I have a TA4 and 6; no jumper used for thermocouple; jumper for 2 or 3 wire RTD (if memory serves me - I'm over 50 so my memory is sketchy at best). Once wired correctly you can adjust (compensate) the temp + or - by pressing SET for 5...
Just thought I'd revisit this thread and post something current. I get my bottles filled at Keg n Bottle on Massachusetts Ave in Lemon Grove. $17 for 5# and $22 for 10#. Price has varied depending on who's working. They prefer frozen bottles and they do not use a weight scale; just a...