What component of the automatic fire extinguishing system detects smoke or heat?

In an automatic fire extinguishing system, the smoke or heat is typically detected by smoke detectors or heat detectors. Smoke detectors sense the presence of smoke particles in the air, while heat detectors respond to changes in temperature caused by a fire. These devices send signals to the control system, which activates the extinguishing mechanism when a fire is detected. Together, they play a crucial role in early fire detection and response.