UDS help

Discussion in 'UDS Builds' started by smoken george, Feb 14, 2011.

  1. I built my first UDS I have a concern about temp. I have 2 temp probes in it one in the lid and one in the side of the uds. So I cooked some ribs in it. To double check I put my digital temp probe on the rack though a potato it read 275 the one in the lid read 200 the one on the side read 180 I am confused of why, The ribs come out good and only took 4 hours to cook. After I was done I checked all of the temp gauges in boiling water and all registered between 210 to 215 ??
  2. rbranstner

    rbranstner Smoking Guru OTBS Member

    I have issues with one of my analog probes that is on the side of my drum. The stem is only a few inches long so it doesn't read very well compared to the other analog one that has about a 6 inch stem. There can be some hot or cold spots on your drum especially when it is first coming up to temp and the fire is still spreading through out the whole barrel. My longer stem analog probe reads dead on to what my two digital thermometers say. Another thing is when my drum is coming up to temp and I am trying to get things stabilized and get my whole basket lit I will notice that my digital probes are reading different because one is in the middle of the smoker which is directly above the heat the the other one is more towards the side of the drum which will read lower until everything stabilizes. The more you run the UDS the more you will figure out how your drum is going to run.

    Even when everything is all stabilized you can still get some hot and cold spots from time to time. Usually if I am smoking a butt or brisket or something I will make sure to turn the meat 180 degrees around half way through the smoke just to make sure the meat gets done all the way through evenly.

    I guess the moral of the story is the outside of the barrel can be a little cooler than the inside especially if you have a really small diameter fire basket. That's why I am glad I went with a larger fire basket.
    Last edited: Feb 13, 2011
  3. smokemaster

    smokemaster Smoke Blower

    I have a 9 degree difference between my analog therm on the side and my digital probe on the rack.
  4. meateater

    meateater Smoking Guru SMF Premier Member

    I have a analog on my lid and one on the side about 3/4 ways that have a 1" stem that I only use for for reference. I use a water pan in mine to eliminate sour smoke. I also have a traingle vent system on my lid, I started out with one in the back and found that was a hot spot. I added two more and now have even heat flow throughout my drum. I also have a door on mine just because. Anyways, it's all good. Anyway you make it and it works that's why no two are alike.


  5. deannc

    deannc Master of the Pit

         Not sure of the positioning of your lid probe, but I would think the one in the lid would be the hottest. If you are only using a short stem probe on the side (that doesn't reach out over the hot coals) it is going to read lower than your digital that is placed on your rack, directly over the hot coals. My side probe varies between 10° and almost 30° depending on the situation.  I will probably always use my rack thermo and when I build future drums I don't think I'm going to even bother with the analog probes.

    Meateater, the triangle vent idea sounds like a good one!  Makes sense now why some of the drum plans have 8 or 10 holes placed equally around the lid.  

    I haven't noticed any major issues with hot spots (knocking on wood)! 
  6. Thanks for the info, My analog does have short probes and my charcoal basket is 17" in diameter not real big but not to small ether. Also use my weber lid.

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