Originally Posted by Demus
How do you know the one is more accurate at mash/sparge temp? I couldn't figure out to calibrate mine at anything other than boiling or freezing...
I use a NIST certified thermometer and a hot plate. Do a two point calibration with your cold and hot. Then check in between at your mash temp. I like 150, so i boil on one hot plate then move to the other in the ball part of 150. then slowly bump it up until the NIST reads 150. If I have trouble calibrating it, i will just write down the difference and then i know if i want 150 i have to have it read 154 for example. You don't need a NIST but it's sure nice to have one available.
Similar to the pH meter I would only get one that will allow you to use a two point calibration. If you are going to use it for your mash and to check your source water, I would recommend calibrating with 4 and 10 buffer then checking against your 7 buffer.