Originally Posted by RiverCityBrewer
Most of the bimetal thermometers I have are the most accurate in the middle third of their range... that said, did you take it up to normal mash temps and check it against your digital since that is the temp range that you want to be accurate. Also, have you checked your digital against a quality lab grade thermometer? Digital thermos can be off just as easily as bimetal.
Great questions. My brewmometer has been spot on, well 2 of the 3. One was dragging on the faceplate and would read correctly once I tapped on the glass.
I have not calibrated the digital against a lab grade. I have checked it in ice water (32 degrees) and boiling water/wort (212 as I am at sea level) and it was spot on. Also checked it against 2 other digital thermo's and they were within tenths of each other.
Northern Brewer sent me a replacement for the one that was dragging and I installed it tonight.
All three were at the same ambient temp when I installed them. The difference was I calibrated the new one in the bent position.
I did this by setting it to the same temp as the other 2 for a quick start. The other 2 read identical.
Then I noticed the other 2 were aimed lower than the new brewmometer, so I decided to bend them up to match for better viewing.
After doing this, the older 2 didn't match the new one any longer and they were 2 degree's off from each other.
So I filled each pot with tap water, added the probe and the older 2 were way off and the new one was only about 1/2 degree off.