What is the basic concept of a multi-criteria detector?

• A. A detector that uses multiple sensing modalities to decide if there is a fire
• B. A detector that uses a single sensing modality
• C. A detector that logs data without signaling
• D. A detector that can be triggered manually only

Answer: (A)

Using more than one sensing input to decide if there is a fire is the defining idea of a multi-criteria detector. By requiring several indicators—like smoke plus heat, or smoke plus carbon monoxide—the system cross-checks signals so a fire is confirmed before sounding an alarm. This approach reduces false alarms from non-fire conditions that might trigger on just one cue, while still providing quick detection when several indicators appear together. In practice, you might see a detector that blends optical smoke sensing with heat sensing or combines gas sensors with particle sensors, all feeding a logic that triggers the alarm only when the criteria align. The other scenarios don’t describe this cross-checked decision process: a single sensing modality isn’t multi-criteria, logging data without signaling doesn’t alert, and manual triggering relies on a person rather than automatic sensing.