Author Topic: Temperature Test Part 2  (Read 159 times)

Offline Habanero Smoker

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Temperature Test Part 2
« on: July 23, 2020, 02:34:20 AM »
An even longer post.

Test #2 at shelves 1 & 3 rack positions (from bottom).
Ambient temperature during test 72°F – 77°F, calm, humidity 80% - 71%, damper removed; set temperature 251°F. I ran this test to check the temperature at the lowest position, and  position 3, the position I would likely use most. Shelve 1 position, the rack is about 1-inch below the sensor. Shelf 3 position is about the middle of the smoker. Using two racks and four probes, I place one probe about 1-inch from the back wall, and the other 1-inch from the front end of the rack. Ran test with empty cabinet, and the smoke cycle off.

The preheat recordings where similar to Test #1. It took about 20 minutes to reach the target temperature, then smoker overshot the temperature by 5 degrees. The difference in readings is that the ThermoWorks Signal read much higher. The highest reading difference between the Bradley sensor and the ThermoWorks Signal during the preheat; for the Bottom Rack Back (BB) 61°F; and Bottom Rack Front (BF) 24°F - Top Rack Back (TB) 40°F; Top Rack Front (TF) 20°F. Eight minutes after the temperature stabilized at 251°F the readings were pretty steady with a difference at (BB) 36°F, (BF) 20°F; (TB) 25°F, (TF) 19°F. This readings remained steady, with a 1 – 3 degree variance over the next twenty minutes. What surprised me was the front probes on the bottom and top racks were very close to reading the same. The stable readings when the Bradley was reporting 251°F; the Signal read; (BB) 288°F, (BF) 272°F; (TB) 276°F, (TF) 271°F.

Test #3 with bisquette burners on:
Next I turned on the smoke cycle. The bisquette burner is located in the rear left corner of the cabinet. The greatest difference in readings while the burner heated up was; (BB) 48°F, (BF) 18°F; (TB) 28°F, (TF) 17°F. According to the Bradley display, the smoker overshot the target temperature by 7 degrees. Once the temperatures became stable I was surprise to see the temperature on the front probes, had come within 9 degrees of the Bradley display. (BB) 38°F, (BF) 9°F; (TB) 28°F, (TF) 9°F.

Test #4 @ 200°F, with bisquette burners on:
Finally I reduced the temperature setting to 200°F. After the cabinet temperature steadied, the four probes were still reading high, but more even across the racks. (BB) 24°F, (BF) 20°F; (TB) 22°F, (TF) 20°F.

These tests are disappointing, but not a deal breaker. The difference in temperature reading during the preheat is not a concern, but the temperature difference once the temperature steadied is a concern. This was an empty cabinet test, so I don’t know how different it will perform with food in it. Although the Signal showed it was running high, it also displayed that it was maintaining tight temperatures. I just have to learn how this cooks.  It does cook a lot better than my kitchen oven. The difference in temperature ranges would be alright for hot smoking and barbecuing, but smoking sausage may be a little tricky.

Hopefully firmware updates will improve the accuracy of cabinet temperatures, or give the user the option to offset the display reading by up to 20 degrees or so. I may do a white bread test, this test consist of placing slices of white bread on all shelves and check if they are toasting evenly. Some use refrigerated biscuits, but I find using bread give you a better visual display of all the hot and cool spots.


     I
         don't
                   inhale.
  ::)

Offline manxman

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Re: Temperature Test Part 2
« Reply #1 on: July 23, 2020, 11:06:59 AM »
Interesting and useful information, the white bread test sounds like it could also be of use. Given this is advertised as a smoker for professional use I would have expected better and more uniform temperature control throughout the whole cabinet and more accurate in built sensors but I suppose as long as you are aware of potential problems then adjustments can be made accordingly as you suggest Habs? Ideally Bradley will also take an interest in your data and comments which could help facilitate a fix?

I would be interested to know the temperature and temperature distribution as measured by the same third party sensors compared to the Bradley sensor readings with just the puck burner on and both the heating elements off compared to ambient in an empty smoker, I am very dubious the P10 is suitable for cold smoking ice or no ice!?  ::)
Manxman

Offline Habanero Smoker

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Re: Temperature Test Part 2
« Reply #2 on: July 23, 2020, 01:30:57 PM »
I still can't figure out, or have any idea why the rear of the cabinet was so much hotter, when the bisquette burners are turned off. Unless for some reason they programed the PID to control each element separately, and at different temperatures. But then too, I haven't figured out the draft flow of this unit. :)

Once I realized the huge difference in the readings between the Bradley sensor and the Signal, I realized the cold smoke test needs to be redone. As soon as I get some cooler weather I'll run a test. For now and into the near future the overnight lows will not get below 65°F, and daytime highs are expected to be in the high 80's and low 90's.


     I
         don't
                   inhale.
  ::)