Digital thermometer calibration?

[OofC_Zer0]

So I have a digital thermometer (Taylor brand). I have had a couple brews at lower efficiency than my first few. So I checked the temp of my water before I added grains with the digital and with an old school mercury thermometer. The mercury one was about 3 degrees or so lower. So I think my efficiency problems are coming from missed temperatures. I was wondering if there was a way to calibrate this thermometer, or if anyone had any suggestions on different thermometers with wired (or wireless) probes that don't cost a fortune! Thanks in advance. HAPPY BREWING!!

 

[Bobby_M]

I've had two of those exact ones for years and I basically just marked how far they were off right on the face with a sharpie. One of mine says +4 and the other -2. I referenced them to a glass lab thermo at 150F and that's what they were off.

 

[thargrav]

The thermometer should have come with a set of specs and most of these are garanteed to be linear to within +/- 2 fegrees F. And BTW, this is better than the advertised accuracy of and bimetal dial thermometer. Also, they can not be calibrated - the only option you have is to compare to a known good thermometer, but how do you know that the one you are comparing to is more accurate.

Bobby M did it right - he compared his to a glass lab thermometer, but there is another way we can test ours. You can fill a glass of ice water, wait until the outside is sweaty then take the water's temperature - it should be 35 degrees F. Then bring some water to boil and measure the boiling water temperature - it should measure 212 degrees F - temperature adjustment based on your altitude above sea level. The boiling point of water drops by almost one degree per 500 feet above sea level.

Sea Level = 212F
500 Ft Above = 211F
1000 Ft Above = 210F
1500 Ft Above = 209F

Once you verify your themometer you should be good to go.

And BTW, every digital thermometer I've checked has been very accurate.

 

[Smits07]

I had that exact thermometer, after this weekend. It is now in the trash. My efficiency had suddenly dropped extremely. I compared it to other thermometers, and I realized other thermometers were reading it 4-5 degrees off. However, it got boil temp accurate when I put it in boiling water though. It is now in the trash, and I am going to look for another, more accurate thermometer. Its readings have cost my a lot of money in lost efficiency...

 

[adam01]

I've got an earlier taylor model - reading 8 degs low.

In fact, I tested 5 different thermometers, glass, 2 digital, 1 lab quality digital.
All were different for temps from 32, 100, 120, 140, 160, 180, 212.

 

[edroberts]

I've had the same problem. The last couple beers I've made seemed to dry out more than I had expected. Boiling temp seems to be right on. 32F water reads 67 degrees, even after using the "reset" button to recalibrate. At mash temps, I was reading 10 degrees higher than the thermometer that came with my turkey fryer, 15 higher than a meat thermometer I had, and 20 higher than a good ol' red alcohol candy thermometer. Needless to say, I have no idea what I'm mashing at this morning. I'll be seeking out something more durable and accurate than this model very soon. Any suggestions?

 

[mpride1911]

After just finishing up my third all grain ever, I basically confirmed my doubts over this exact thermometers inaccuracy. After using my Therminator to chill the wort, the temp would not drop below 74 on the Taylor. But once in the carboy, the Fermometer attached to the side said that my wort temp was actually closer to 54. I have a pilsner in the chest freezer and the fermometer there reads 54 and so did the Johnson controller controlling the freezer. My Taylor said it was 74. I tried calibrating with boiling water and the reset button but nothing changed. In a bowl of ice it read around 67 deg. Hopefully explains why my efficiency has been a horrible 55%. This thing is trash and I'm going with mercury until I can figure something else out.

 

[dbsmith]

I had that same thermometer once too. I got the probe a little too wet and the bam, it was completely out of whack and read everything way too high. Into the garbage it went as well. This brings me to another thought. Why aren't there any thermometers out there with a probe for specialized tasks such as brewing? These thermometers I see have crazy ranges from -20 to 300 degrees, which I understand because they are for cooking. How accurate can they be? How about a fermentation thermometer, with a range from 40 degrees to 85 degrees? There are some nice thermometers out there for the mash tun, which I have, but I would love a specialized fermentation thermometer (besides the dang stick on one). Anyone know of any suited well for this purpose?