Thermometer differences


 
S

Steve G.

TVWBB Member
I have one of those New Braunfels smoker thermometers from Academy that I installed in the lid of my WSM. (drilled out and mounted in the lid) It has a 3 inch probe on it. I was concerned about how accurate it was and bought a cheap oven thermometer to sit on the top grate while cooking. I get about a 25 degree difference between the two. So this leads to a few of questions.

1. Is there THAT much temp variation between the lid and the top grate?

2. Could the grate temp be reading lower since the thermometer is closer to the meat...which is not as hot as the rest of the pit?

3. Would I be better off with a 6 inch probe? If so, where can I find one of these?

Thanks
 
1. Yes, they're can be, depending on a few variables one of which is probe length. My difference is usually ~ 20.

2. Yes, if the therm is quite close.

3. Not necessarily. If you do a few cooks with both therms you'll get a good idea of the spread. That's all you need. A long probe won't work with tall roasts; won't fit. I do use a 6" but I can move it in and out as needed.
 
Did you test the accuracy of the NB therm prior to installing it in the lid of the WSM? There is a difference in temps from the lid to the top grate...25 degrees, I don't know.

I usually run anywhere from a 12-18 degree difference, sometimes during cooks the temps are the same.

I would not use a 6" stem therm in the lid, you're getting away from the lid temp and there's a chance you might touch some meat that you have cooking.

I also have the NB therm mounted in the lid of my WSM. I also use two Taylor digital probe therms for the top grate and meat temps.
 
Thanks Kevin,

This leads me to my next question:

If I am trying to maintain a 225 temp, which thermometer should I be using to base this temp on? When my grate temp (according to the thermometer next to the meat) says 225, the lid says 250. Should I shoot for 237.5 in the lid and 212.5 on the grate to have an average of 225???
 
Either. Assuming you get a fairly consistent spread you can use either figure--the 225 grate or the 250 lid. Don't average. If you want 225 grate go with your grate temp (the lid will read higher, that's fine). There are times I cannot fit a probe on the grate or the little room left on it would force me to mount it too close to the edge or to close to the meat. In those cases I don't bother, I just shoot for 250 lid.

Bruce's questtion is apt, especially since he uses the same model therm and has a tighter spread.

Note: When using no water in the pan or no pan the dynamic is different. In these cases I'm lookin for high temps so I don't bother mounting a grate probe; I just go by lid.

Also, for low-and-slows temp levels of 10-15 degress either way from your 225 grate target are not a problem. Your cook might be a little shorter or longer but your meat will be fine.
 
I am concerned that I 'messed up' my NB thermometer when mounting it. I used the method where you screw the thing into the hole rather than a larger hole with washers and an underside nut. I had to really crank that baby down to get it in. Not sure if the stress of twisting it could have caused some problems or not. Can this be a factor? I need to remove it and test it in water I guess.

Here is what concerns me about it: Before I mounted it, I used to use a cork with a hole in the middle and stick the NB thermometer through it in one of the top vent holes. Ever since I mounted it, it seems like it tends to be harder to keep the NB temp down around 225...where before, it seemed easy. That is what makes me wonder about if I did something to it when mounting it. I only did about 4 cooks before I mounted it though, so there is a thought of the WSM becoming more seasoned casusing the temps to be harder to keep lower. Thoughts????
 
If anything, after use and the build up of gunk within the pit, the WSM will not run as hot as it did when new.

A 25 degree spread does seem a little high, but it wouldn't worry me IF I new I was getting an accurate reading through the dome and at the top grate. If you can remove the dome therm and test it, then that probably would be the way to go. I don't think I would want to use a 6 inch probe for my dome therm.

Paul
 
I used to always try and hook up my therms to both of my grates and keep a constant eye on those temps. That became too much hassle. I now just use a lid temp of about 260* Then I know that the top grate temp will be running at about 245* and my bottom grate temp will be around 230* It makes it a lot easier.

Ditto on the newer WSM cooking hotter. Did a double WSM cook yesterday. My newer WSM cooked much hotter (+20*) than my older one. Barely needed to open the vents on the newer one.

Rick
 
You must log in or register to reply here.

 

Back
Top