Understanding how the parts of your process control system work
together will help you select an approach that best manages your
Whether cooking or curing, drying or heat setting, every heat processing application requires controls to adequately manage the process and ensure that acceptable product is produced. A process control system consists of four key parts: feedback control, final control element, process heater and sensing devices (figure 1). A closer look at how these parts work together will help you understand the basics of process control.
A thermistor is a nonlinear device whose resistance varies with temperature. Thermistors are used at temperatures under 500°F (260°C). Fragility limits their use in industrial applications.