Temperature Probe Offset observations & procedure on Bullseye Deluxe RT-380 X

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SweaT-rex

Well-known member
Messages
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360
Location
Metro ATL
Grill(s) owned
  1. Bull
  2. RT-B380X Bullseye Deluxe
I wanted to see what the actual temperature probe offset was on my new Bullseye Deluxe so I checked it with a known accurate analog thermometer today. The thermometer was placed through the meat probe hole with the tip situated about 1" from the grill's probe tip. The grill was set at 250 degrees and allowed 20 minutes to achieve steady state. The analog probe read 295 degrees. I opened the Recteq App & went to Settings, then to Advanced Settings, then unlocked it, and then gradually advanced the Temperature Calibration setting eventually ending up at +15%. This resulted in pretty much exact correlation at 300 degrees, 250 degrees, & 225 degrees. There were no flame outs. The ambient temperature was about 78 degrees with a mild breeze. Recteq Ultimate Blend pellets were used.
Hopefully, the attached pics are explanatory. In summary, my Bullseye Deluxe was running 45-50 degrees hotter than the grill probe indicated, 2) it's easiest to change the offset in the App rather than on the grill controls, & in my situation at least, the proper setting was +15 %, & 3) the grill seems to function as usual at usual smoking ranges. Also, the analog thermometer confirms that the grill has a 15-20 degree temp swing on either side of its set point at steady state which is not evident on the grill's display. This was present both before & after resetting the temperature calibration.

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Nice write-up, @SweaT-rex. Not trying to be a smart-ass, but how do you know the analog thermometer is accurate? In my experience, they usually aren’t. Did you run a cold (ice-water bath) and/or hot (altitude-adjusted boiling bath) check on it? Just my own curiosity here.
 
Nice write-up, @SweaT-rex. Not trying to be a smart-ass, but how do you know the analog thermometer is accurate? In my experience, they usually aren’t. Did you run a cold (ice-water bath) and/or hot (altitude-adjusted boiling) check on it? Just my own curiosity here.
I did the boiling water test last night & got a reading of 210 degrees. I live at exactly 1000 ft above sea level.
 
I did the boiling water test last night & got a reading of 210 degrees. I live at exactly 1000 ft above sea level.
Perfect! That’s right on the money for your 1,000 altitude. You have a good analog thermometer. Sounds like you have everything calibrated just right on your grill. Nice work!
 
I just saw this in my foraging around and it proves that there is value in everything.

I have been playing with my new 380X and have been wondering if it would be safe to route the cable on my TW RFX Gateway Ambient temperature probe through to the cooking grate. I was unsure as to the temperature of the circulating air leaving the diffuser to travel to the grill. The ambient temp probe for the Gateway has a top end of 575 so it will never work at the 380X Maximum temp ranges, but will still be viable for most cooking temps that I use.

My issue/question was whether or not the hot circulating air was going to be significantly superheated to a point hat it could melt my cable where it passed by the "open air" sides onto the "diffuser protected" portion of the grate if that makes sense.

I will simple probe the gap so to speak to confirm that it is below 575 degrees.

The RFX probes themselves are perfect for the 380X environment being cleared to 1000 degrees on the exposed ends. I might delete the rubber colored rings though. I don't know the melting points. :)

v/r r
 
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I don't know the melting points.
Just for information, Combustion Inc is now offering numbered metal flags that clip onto the probe shaft. Since the shaft on the CI probe is about the same size as the RFX, they might fit it too.

I have a set of the flags coming in a couple of weeks with my new Gen 2 CI probes and will try them on my RFX and Meater 2+ probes as well. I will post the results.

IIRC, the colored rings are made of hi-temp silicone and are rated at 550F. I think TW uses the same material for the rings as it does on its hi-temp spatula, spoonula, brushes, etc.

EDIT: Just checked the TW website and the rings (and other TW silicone products) are rated at 600F.
 
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Jim, thanks much. I would love numbered flags. I will wait till you confirm they will fit the RFX probes though. I am the master of ordering "wrong stuff". :)

v/r r
 
Oh boy....looks like the "enablers" have found a new "enablee"....

Careful rhouser, I hear its a deep rabbit hole....

🤣😂🤣
“Rabbit hole?” Not so; it is an “information portal” for those desiring to be “in-the-know.” 🙄
 
This is the most up to date (2024) "My Bullseye Runs Hot & Needs Offset" thread so just posting my experience in here rather than starting another,

Have had my RT-B380X all summer and some very mixed results with it. Especially trying to smoke, and not "hot grill". A lot of things either just plain overcooked, or, came out "OK" but cooked way faster than "they should". Only one example - what was supposed to be a long low & slow all day pot roast smoke being done in barely a couple hours like it was just chucked in a hot oven.

Well... finally this week I tossed a couple other thermometers at the grill while doing some wings, and - sure enough those readings ran 10-20% over what the RT-B380X would read for internal temp.

Now - I definitely am aware that because 1. The grill temp fluctuates a bit and thats normal, 2. The temp display is 'filtered' to slow those fluctuations (so people don't freak out if its flittering up and down too much) that any single comparison reading isn't going to be perfect, but still, over time and a lot of samples the temp inside is always too hot.

I'm also aware (mentioned in this thread) that my other thermos might not be perfect, but by using a couple and doing a few other spot tests with them, the results are close enough to confirm.

Seems like this has been a pretty consistent issue and the reports of needing an offset that's like 15-18% is super common.
I'm going to put an offset in in that range, and then run a cook with the extra thermometers and see what I get.

It sure would be nice if there was an easier way to calibrate the offset on these, and, if RT had better QC on them out of the box. I wonder what makes it such a common consistent thing. I use thermocouples in my work from time to time, and I wonder if they have an engineering fault with a "cold junction". This has to do with using standard copper instead of special alloy wire to connect thermocouples and easily could be creating this issue and also woudl explain its consistency - like if somebody at the factory cheaped out on wiring for the thermocouple signal inside the controller...
 
Did you measure the grill temperature at the location of the thermocouple, or on the cooking surface? One of the problems with most pellet grills is that they measure temperature at the very side of the cooking chamber; usually right next to a lot of metal that serves as a heat sink. As a result, the temps measured there can be significantly different from the area where you actually cook.

Not a promo here but my MAK 2-Star at least has a removable thermocouple on a shielded cable that allows it to be slipped out of the holder and placed right next to the protein being cooked. Several here on the forum rely on third-party temperature measuring devices that include an ambient temperature probe that can be similarly placed. Unless the built-in thermocouple is made moveable, it will never give you an accurate temperature reading on the actual cooking surface.

You are correct regarding temperature fluctuations and the controller averaging them out. That’s why even a quality thermometer will only give you an accurate reading at any given moment in time because it lacks averaging ability. Again, not a promo, but I have found that a 4-port ThermoWorks Signals unit is an indispensable tool for managing cooks. I have four ambient probes with clips to position them on the grill. This allows me to check four separate locations on the cooking surface. I don’t usually use the four-ambient-probe setup during cooks, but it sure does help me learn the true ambient temps in four locations on my grill.

Sometimes, it is hard to remember that these grills are not pieces of laboratory equipment and, they require us to learn their quirks and how to adjust for them. Coming from an old stick-burner background helps in this regard because we were always flying them by the seat of our pants…and a analog thermometer. :ROFLMAO:
 
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On the phone with 'customer service' this morning, he's claiming the temp probe on the 380 is correct, and anything else, third party temperature probes are wrong. He's telling me there is no problems with the 380 and temp swings, it's all in the customer's head... the temp on the controller is the temp that you set, end of story... what a tool... he did not recommend increasing the feed rate, or adjusting the temp of the unit with the offset feature... I'm assuming that this guy's bonus is a function of the number of returns he has to process... not sure what to do... I'll reset the temp offsets, set the feed rate back to 8, and try to get temps in the 225 range... if I can't, I guess initiate a return. But not sure how that is going to work, threw the box away when I unpacked the boat anchor.
 
On the phone with 'customer service' this morning, he's claiming the temp probe on the 380 is correct, and anything else, third party temperature probes are wrong. He's telling me there is no problems with the 380 and temp swings, it's all in the customer's head... the temp on the controller is the temp that you set, end of story... what a tool... he did not recommend increasing the feed rate, or adjusting the temp of the unit with the offset feature... I'm assuming that this guy's bonus is a function of the number of returns he has to process... not sure what to do... I'll reset the temp offsets, set the feed rate back to 8, and try to get temps in the 225 range... if I can't, I guess initiate a return. But not sure how that is going to work, threw the box away when I unpacked the boat anchor.
Can you get it (380 probe) into a cup of ice water to see what temp it registers? If you get stuck with it, you can maybe figure out your offset this way.
 

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