RTD vs thermocouple: choosing industrial temperature sensing
Compare RTDs and thermocouples on accuracy, range, speed, and wiring — plus when to use thermistors, IR, or fiber-optic sensing instead.
Control loop
Feedback path from measurement to corrective action.
A feedback path that measures a process variable, compares it with a setpoint, and adjusts a final control element. A loop includes the sensor, controller, output device, process, and tuning; a PID algorithm is common but not required.
See also: PID loop · DCS · PLC
Use the concept: 4–20 mA loop scaling · Compressed air leak cost calculator · Engineering unit converter
In depth
PID loop tuning: a field guide for process engineers
P, I, and D in plain language — manual tuning, Ziegler–Nichols, lambda, and the anti-windup and filtering details that decide whether a loop behaves.
Hazardous area classification, explained
Zones, divisions, gas groups and temperature classes decide which equipment may sit in a classified area. IP and NEMA ratings answer a different question.