Calibration Question

GeorgiaBorn

Hey folks. I calibrated my thermometer last night. According to my location above sea level and the barometric pressure, my boiling point is 209.75

Much to my surprise, my thermometer was 40 degrees too low! Makes sense when compared to my DigiQ cook this past weekend. Anyway, I adjusted it to the correct temp and replaced it in the Egg. Today, I noticed that the temp reading on the thermometer was about 95. The temp here today was about 80 and the temp in the Egg was about the same. I couldn't understand why the thermometer was reading 95.

So, I brought it inside and did a ice water calibration. The temp wouldn't get below 55-60 when it should have been 32-33. I know the Egg thermometer doesn't have a reading below 50 but it never got close to that.

So, I did the boiling water calibration again and this time it was spot on at about 210.

Is this normal? Shouldn't the thermometer be reading the correct air temp when it's not in boiling water? It was reading 90 inside my house, and my thermostat is set on 72.

BigA

maybe the needle on the thermo is a little sticky, try tapping on the cover

GeorgiaBorn

Sticky? Seriously? LOL. Pretty sure that's not the problem if in fact there is a problem at all.

AZRP

That's normal, all four of my therms are sitting at 100 and its a little over 80 outside. Three of my therms are Tel-Trus and one is a BGE. I think they are made to be more accurate in the 200-600 range. -RP

Capt Frank

I agree w/ AZRP. Just replied to a similar post a little while ago. My therms are dead on at 212, but read approx 20-30 high a ambient temp. Keep in mind that these are not high dollar, lab quality instruments

gdenby

An Egg isn't as much of a heat containing environment as a green house or a car. But on any sunny day, when the night has not been very damp, expect the dome therm to read at least 20 higher than ambient air. Assuming the Egg is well sealed. During a hot summer day, I become suspicious about the therm calibration if the dome temp isn't 50 above outside ambient. I've had a therm reading of 180 with no fire. Just like getting into a car sitting in a parking lot.

And, as said, these are not the most precise devices.

lowercasebill

i dont mean to be a jerk [but it is my nature ] here but you dont cook anything on the egg below 225 so if it is accurate at 2oo+ there is nothing to worry about.. with a bi metal thermometer with a lowest reading of 50 it ain't going to do 32.. i like my tel tru therms and if you are concerned about calibration.. leave the clip off the thermometer so you can pull it out stabilize the egg at 350 remove the thermometer and stick your thermopen in the hole and compare..

Capt Frank

Gdenby is exactly right! I have never tried to check it, but I am sure the internal temp of the egg is going to be higher than the outside temp most of the time, plus, as lowercasebill puts it, it dosen't matter anyway

Little Steven

GeorgiaBorn,

It is not the best thermometer. I calibrate mine at around 300* and it works ok. Tel-trus are a little better.

Steve

GeorgiaBorn

Thanks everyone for the input. After re-checking the calibration tonight, I was somewhat convinced that it was right but was a little concerned about why it was reading so high when not in the boiling water.

No, I don't plan to cook anything at the temp it's reading now without the Egg lit (around 95) but I thought it was strange so I had to ask.

Thanks again guys.

2Fategghead

Be happy it was not 100F degrees to hot and you were in the food burning business.

THA

all measuring instruments are made to be accurate to a percentage of reading within a certain range and with the closer accuracy being in the mid range. As you approach the extreams of the range, the percentage allowed for error becomes greater. Since these thermometers are made for higher temps 200 to 500, I would not expect the BGE thermometers to even be within 20 degrees at below 100 degrees and especially near freezing. Also the quality of build makes a difference. Teltrue vs BGE supplied would show a big difference.

BigA

Sticky?? Yes? Seriously?? Yes? must be that you have never had a needle stick on a guage before, sometimes the needle gets hung up on something inside, like the shaft that it spins on has a bur on it. but obviously i must be wrong and that never happens. you must have never owned and older car where the gas gauge needle or temp needle in a car gets hung up. so yes it can happen. i am glad that your thermometer is working, and that you arent concerend about it anymore. but my apologies for making you think it was a joke :huh: when you ask a question on here expect to get a lot of responses from people that have had experienced that problem.

BigA

:laugh:

BigA