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c) Damper position. Keeping the damper open will result in better temperature stability
because more heat loss is created. This is important when the temperature is set below
140 °F. When the damper is closed, the temperature will take a longer time to drop if it is
overshot during initial heat up. At higher temperatures, closing the damper will not affect
the performance much because the heat loss from the wall of the tower is increased,
d) Temperature uniformity of the smoker tower. Our test showed that when all the
shelves were empty, the temperature inside the smoker tower is fairly uniform except in
the back half of the lowest shelf that is close to the heater. Users should avoid placing
the sensor too close to the heater because it does not represent the temperature of the
rest area. When the shelves are filled, temperature variation might depend on how the
foods were placed. The bottom shelf can become hotter if more food is placed in it to
block the hot air from going up.
e) Operating the controller when ambient temperature is below 32 °F (0 °C). The
controller
reading is only accurate for temperature ≥ 32 °F (0 °C). In addition, if the
ambient temperature is below 14 °F (-10 °C), the controller will not function because it
can’t read the temperature correctly. In that case, users can warm the sensor by holding
it with their hands. Once the sensor is above 14 °F (-10 °C), it will turn on the heater.
Once the inside of the smoker is heated to above 32 °F, the controller will run by itself.
3) Initial settings
In case you have changed some of the parameter but want to set the controller back to
its original condition, here is a list of the initial settings.
Symbol Display
Description
Range
Initial
P
p
Proportional band (in 0.1 degree)
0-600
70
I
I
Integral constant (second)
0-900
600
d
d
Derivative constant (second)
0-300
150
AT
A
Auto-tune
0=off 1=on
0
Cycle rate (second)
1-100
2
SC
SC
Off set (degree)
-20~+20
0
Out
Output power reduction (%)
1-100
100
C-F
C-F
Temperature unit
°C or °F
°F
Table 1. List of system parameters and its initial settings.
