Dial Thermo for Center Grate Temp

[ddave]

I finally got around to installing the deep fryer thermometer in the side of UDS 1.0a so that I don't have to do the temp conversion anymore.

Here it is with its original thermometer -- a Teltru BQ300 with 3" stem.



Nice thermometer but the stem isn't long enough to measure the center grate temp so I always had to add (by my observation anyway) 50° to 70° and also wasn't much help when the drum was warming up.



Got a 3/4" bolt to cover the existing hole and had a buddy who owns a fab shop drill it out for me.



Here's the bolt installed.



Covers the hole nicely.

A shot from the inside.



And the thermo in place with the grate on.



Thermo slides in and out in so it doesn't get in the way of the charcoal basket and the long bolt supports it so it doesn't need any other support from the inside.

Doesn't look quite as nice as the Teltru, but I'll use it this way for awhile.



If Teltru ever makes a smoker therm with a 12" stem, I'll be all over it.

Dave

 

[rickw]

Nice work. Will you have to do a reverse conversion to figure out the outer temps of the grate?

 

[beer-b-q]

Great idea drilling the bolt out to fit the stem...

 

[ddave]

LOL, never thought of that. I guess if I wanted to know the temp at the edges of the grate I could slide out the thermometer part way. Or I could put the Teltru back in its original spot and drill out a smaller bolt to mount the 12" thermo and use them both.

Ultimately I don't really care what the outer temps are because I can only use one "control point" and I know that it will be about 50° or so lower.

Dave

 

[helljack6]

Does it react as much as a digi therm when you put cooler meat on the cooking grate? Or does it seem to hold temp pretty solid regardless?

 

[geek with fire]

Nice setup. I do have 2 questions:
1.) How will drippings effect the temps
2.) Will the metal bolt in contact with the probe effect temps? I've never used one of those probes before, but my thermocouples don't like metal mounts. I have to insulate them with a rubber gromet.

 

[ddave]

It is not as fast as a digi but does seem to follow the pattern reliably. When I take the lid off, and do something and replace the lid, it initally reads lower. Then it climbs a bit (normal heat spike). Then it settles back down a bit as the excess oxygen is consumed.

I'm not really sure since I haven't compared it with a digital on the grate yet. The pot clip that comes with it is metal but not nearly as heavy as the bolt. Since it is a 12" probe, I would assume the end wouldn't be affected that much by the bolt at the other end, but I can't say for sure.

As far as the drippings go, I would assume it would make it read lower than actual smoker temp. I smoked a couple of pork shoulders yesterday and they took a lot longer, but it was the first time I didn't foil at 165°. I didn't use a digital but if the dial was off and I had to guess which way, I would say it was actually reading higher. Plus, since it slides right out, it would be no problem to take it out and wipe it off from time to time.

I'll have to compare it with a digital to make sure.

Dave

 

[ddave]

Here's an update in response to Nutzman and Geek With Fire:

I have the drum going now empty and the dial thermo is dead on 250° and the digi probe (Taylor 1470) says 265°. It has been running for awhile. The tips are within an inch or so of each other with the dial thermo tip below the grate and the digi probe tip above the grate.

I'm not sure what effects the fat drippings would have but I "think" it would make cooler than the actual air temp. The bolt doesn't seem to be affecting it though.

Dave