Question

Ionization detectors and photoelectric detectors are used as part of which of the following: security systems, fire detection systems, or mechanical controls systems?

Answer

Ionization detectors and photoelectric detectors are used as parts of early-warning fire detection systems. Ionization detectors sense the microscopic particles of combustion during the incipient stage of the fire. Photoelectric detectors are triggered when smoke particles obscure a beam of light in the device.