Which type of detectors contain multiple sensors that respond separately but provide only one alarm signal?

Multi-criteria detectors contain multiple sensors that respond to different types of environmental stimuli or fire characteristics, such as heat, smoke, or gas. Each sensor within the multi-criteria detector detects a specific condition and operates independently; however, when one or more of these sensors identify a situation that could indicate a fire, the system consolidates this information and generates a single alarm signal. This is beneficial because it allows for a more comprehensive assessment of the environment while minimizing false alarms, as multiple signals must be correlated before the alarm is activated.

The other types of detectors mentioned do not capture the same function: multi-sensor detectors typically refer to sensors that have multiple detection technologies within a single unit but may provide differentiated outputs, while combination detectors usually integrate two types of single-function detectors into one device but don’t necessarily operate independently in the same way. Photoelectric detectors focus solely on detecting smoke using light scattering methods and do not incorporate other types of sensors.