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Design Consideration_Thermistors Module_measurement accuracy
Fortunately, measuring BBQ temperatures does not great accuracy or precision. In fact, external factors to the ADC can have a greater impact on measured temperatures than ADC measurement accuracy.
First, internal meat "done" temperature targets are more like guidelines. For example, smoked briskets are done when the internal temperature reaches 195-205 deg F. The exact temperature varies from cut to cut and is influenced by thickness, fat / collagen content, etc. I find that in practice, I want to set a near-done threshold temperature, say 197 deg F, and then closely monitor the meat after this temperature is reached looking for a certain level of tenderness. Often, the temperature I pull the cut off at is more influenced by how this particular cut of meat behaves; for example a perfectly cooked brisket has a certain wobble to it when it reaches an optimal doneness and is better judged by feel than any absolute temperature.
Pit (the barbecue itself) temperature has a wide acceptable range as well. For example, I generally want to maintain the pit temperature for a long and slow cook anywhere between 225 and 250 deg F, but up to 320 degF is acceptable. Any variation within this range simply impacts the cooking time.
Consequently, for my purposes, my measurement design goals are to have accuracy and repeatability within ~2 deg C (3.6 deg F) over the temperature range of interest (note that temperature calibration outside this range, say using an ice bath, does not necessarily reflect accuracy give thermistor non-linearity and bias resistor selection).