Review on Inkbird ITC-106VH - Fahrenheit and Centigrade PID Temperature Thermostat Controllers for Sous Vide, Home Brewing, Oven, Incubator (AC 100-240V) by Jathan Louis

Bought a pair of these to control an electric smoker and eventually a wood fired BBQ smoker. I had high hopes but have never been able to tune the PID controller parameters for satisfactory performance. This is probably a great controller for many applications, but I've had issues with my process - an integrating, not self-adapting, heating process. I'm an electrical engineer and I've been very careful in taking accurate and controlled measurements on my open loop stove. I used these measurements to mathematically calculate the PID parameters PB, Ti, Td, dead time, rise time, and response delay based on Ziegler-Nichols tuning, which eliminates most of the overshoot. ST. I expected it to regulate the output more effectively, but normally it would only change the control output within 10°F of SV - no matter how wide or narrow the proportional band (mathematically related to 100/Kp) or control period. Outside of 7-10°F SV it was either 100% or 0%. This oscillated and functioned like a slightly dampened on/off controller with large hysteresis. I could never get it to settle down no matter how wide or tight I tried to make the proportional band. I switched to an Arduino microcontroller and programmed my own very simple PID implementation. I fed my previously calculated PID parameters into the Arduino and got exactly the performance I originally mathematically predicted.