Which thermometer should I use.

Dmoe77

I’m doing 2 pork butts. My lg green egg dome is at 280 and I calibrated it. My two MEATER plus thermometers are at 233 & 236. My inkbird is at 248. 

lkapigian

Personally I’d stick with Dome, let it rock at check internal temp of the butt after a few hours , let the cooker settle in where it’s comfortable, you’ll never get the same reading on several thermometers 

Mark_B_Good

Where are the MEATERs sitting, close to the meat, or in the dome?  There is always a temperature difference between the dome and grill ... especially at the beginning of the cook, and they come together towards the end ... but never the same ... 45F difference in the first period of the cook is not unusual.

fishlessman

i would just go with the dome temp. temps are all over the place putting the probe up top, on the grate, front verse back etc. really big cooks with lots of cold meat in a large, i go with the vent settings for the first several hours

Foghorn

1) Welcome aboard.

2) The tendency in this case (at least the first time I encountered it) is to wonder "which one is correct?".  In my case I eventually figured out that they are all getting accurate readings, but if you sample the temperature around any smoker you will get different readings - depending on the elevation within it (hotter toward the top), airflow (more true in an offset, but can also be an issue on a BGE), and proximity to a cold hunk of meat (often a problem when you close the lid and the dome thermometer sits very close to a cold pork shoulder).  Over time, I've learned that if I've stabilized the egg at a certain temp, I should just add the meat and ignore the thermometers for a while because the addition of the cold meat changes a lot of the readings.  As the meat warms up and shrinks, the dome and grid thermometers become more meaningful/useful.

OhioEgger

Foghorn said:

As the meat warms up and shrinks, the dome and grid thermometers become more meaningful/useful.

Yes, they gradually get closer together, but the dome thermometer (because it sits higher up and heat rises) is always going to read higher than one at grid level. I prefer to just use them as very rough guides and watch the IT of the meat.

Botch

OhioEgger said:
Yes, they gradually get closer together, but the dome thermometer (because it sits higher up and heat rises) is always going to read higher than one at grid level. 

Has that been your experience?  I would think that gases inside the Egg are never hotter than when they are first given off at/thru the burning coals, and will only cool as they rise (PV = mRT); plus, a grid thermometer would normally "see" radiant energy from the coals easier than the tip of the dome thermo, which is kinda centered over the food (and platesetter, if used).  
I haven't compared the two directly that I can remember, and have pretty much given up on thermometers altogether, and just use the dome thermometer to make sure my fire is still burning.   

Botch

Botch said:
...and will only cool as they rise (PV = mRT)

And I realize "Somebody's" Gas Law (can't remember who discovered it, too many brain cells ago) applies more to a sealed system, which the Egg is not, but I do know that gas temps go down as they are expanding (giving them less overall mass/volume, which is why they rise in the first place).  

Foghorn

Botch said:

OhioEgger said:
Yes, they gradually get closer together, but the dome thermometer (because it sits higher up and heat rises) is always going to read higher than one at grid level. 

Has that been your experience?  I would think that gases inside the Egg are never hotter than when they are first given off at/thru the burning coals, and will only cool as they rise (PV = mRT); plus, a grid thermometer would normally "see" radiant energy from the coals easier than the tip of the dome thermo, which is kinda centered over the food (and platesetter, if used).  
I haven't compared the two directly that I can remember, and have pretty much given up on thermometers altogether, and just use the dome thermometer to make sure my fire is still burning.   

Yes, that has been my experience.  If you are cooking indirect and the grid temp is higher than the dome temp, I would suggest that either 1) you have not blocked the rising heat adequately (just a platesetter/convEGGtor is not enough, you also need an air gap and a drip pan) or 2) your thermometer is sitting directly above the rising heat and is not in the silhouette of your heatblocking device(s).

OhioEgger

Botch said:

OhioEgger said:
Yes, they gradually get closer together, but the dome thermometer (because it sits higher up and heat rises) is always going to read higher than one at grid level. 

Has that been your experience?  

Absolutely. I've seen this ever since I got my Egg, and it's consistent.

Mark_B_Good

Botch said:

OhioEgger said:
Yes, they gradually get closer together, but the dome thermometer (because it sits higher up and heat rises) is always going to read higher than one at grid level. 

Has that been your experience?  I would think that gases inside the Egg are never hotter than when they are first given off at/thru the burning coals, and will only cool as they rise (PV = mRT); plus, a grid thermometer would normally "see" radiant energy from the coals easier than the tip of the dome thermo, which is kinda centered over the food (and platesetter, if used).  
I haven't compared the two directly that I can remember, and have pretty much given up on thermometers altogether, and just use the dome thermometer to make sure my fire is still burning.   

Yes, most cooks are with the plate setter, and the hot gases from the coals rise on the perimeter of the grid, then directly up into the dome. The swirl back down to the cook ... so in fact, the cook sees the hot gases AFTER the dome.  This is the shape of the dome creating a nice convection profile, which is actually to minimize the temperature difference across the dome and the cook ... but it isn't perfect. However, compared to say a gas bbq it is FAR, FAR better consistency (there can be 70F to 100F differences between gas BBQ thermometer reading and where the meat is ... even large differences on left side of meat vs. right side ... which means gas BBQ aren't really that great for indirect cooks.

I have put thermometers at dome (through hole), at grid, in meat ... and you can absolutely see that close to the meat, you initially have around a 50F colder difference to dome, then that difference closes up as the meat approaches the finish temperature. Certainly if you are doing low and slow ... and brining your meat to 205F internal vs. a dome of 250F to 275F ... by the end, the difference between dome and grid (not in meat, but beside meat) is only 5F to 10F.