1. Smoke Detectors.
A smoke detector is a device that senses smoke, typically as an indicator of fire. Commercial smoke detectors issue a signal to a fire alarm control panel.
2. Heat Detectors
detector is a fire alarm device designed to respond when the
converted thermal energy
of a fire increases the temperature of a heat sensitive element. The thermal mass and conductivity of the element
regulate the rate flow of heat into the element. All heat
detectors have this thermal lag