🔍 Key Concepts

• Dead band in a temperature controller (difference between upper and lower switching temperatures) • Relationship between band width and how closely temperature stays to the set value • How dead band width affects the number of on/off cycles of the heater over time

💭 Think About

• Look at figure A: if the upper and lower limits move farther apart, what happens to how far temperature can drift from the set value? • If the controller waits longer (bigger temperature change) before switching, will the heater turn on and off more often or less often? • If the dead band is very narrow around the set value, how close will the average temperature stay to the set point, and how busy will the heater contactor be?

✅ Before You Answer

• Compare a wide dead band vs a narrow dead band on the temperature graph in figure A – which one keeps the temperature closer to the set value? • Decide whether more precise control means a smaller temperature swing or a larger one. • Decide whether more frequent switching happens when the controller reacts to small temperature changes or only to large ones.